Monday, February 13, 2006
Same Blog New Site
I would like to alert all of you that I have set up a new website at http://www.ElectricalAdviceBlog.com - A homeowner's guide to electrical wiring and lighting design. The new site is covering the issues facing homeowners when building a new home, adding on to their existing home, or simply rennovating or remodeling.
The three main subjects covered are the electrician's work in the design stage if there are no electrical plans for the job and how the homeowner can engage themself in that discussion. The engineering of the electrical work, code rulings governing plug separation, switching necessities, main service calculations and more. Plus the challenges of doing the work itself, with how-to guides for the do-it-yourselfer.
The web address again is http://www.ElectricalAdviceBlog.com.
The present site, http://www.electricaladvice.blogspirit, will be deleted on February 28, 2006, sign up now to the new blog.
Also, see: http://wwww.stcroixbuilding.blogspot.com, Homebuilding in the Virgin Islands. Where the author is building a home in St. Croix, U.S. Virgin Islands. Check it out!
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Saturday, September 10, 2005
New Site Ready For The Blogging
Finally, our new site is up and running. All old entries to you old comers, all new for the newbies. I hope you enjoy!
Please go to: http://www.ElectricalAdviceBlog.Com
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Saturday, June 25, 2005
IAUL Episode 2
The Ambiance installation I will use for this "episode" is one I did in my workshop, where I have set up my digital camera and tripod to take the various photos for use in this blog, I use it as a shadow box.
After measuring and cutting the 48" track section to fit in between the sides of the cabinet, I snap a 1-hole clip over the track section about 1" in from the edge of the cabinet. I then apply double stick tape to the back of the cut piece. Using as the clips as guides, I adhere the track to the underside of my cabinet with the clips flush with the cabinet face. I can use as few as two or as many as six clips snapped on to the track, for use as guides, if need be, do whatever is easiest for you. Keep in mind that you will have to un-snap each clip at some point, to insert the Ambiance cable, but you can also slide these clips along the track if need be to get them out of the way. Anyway.. You can see that I have cut a 45 degree miter (sort of, roughly) where the track meets the inside of the cabinet and joins with a vertical piece, also cut at (woof) 45 degrees; don't worry, it's under the cabinet where no-one can see it except you! The vertical side track is also adhered to the side of the cabinet with the double stick tape.
Peeling the backing tape off as you go, align the track section against the style and press it hard against the cabinet surface for full adhesion. In some case the tape will have to be supplemented with a 1-hole clip, permanently mounted in place.
Once the track system is complete the Ambiance cable can be persuaded into the track base. If you intend on using the segmented cable markings, this is the time to line them up as you wish.
The cable should snap tightly into base and pushed into the corners with an insulated tool handle, in this case the insulated grip of my diagonal cutting pliers, or dykes. Pushing the cable into the corner in this manner is necessary especially when using the track cover piece, in order to make a crisp 90 degree turn, be extra careful not to damage the cable in any way.
If desired, the cover for the track can be cut with a power mitersaw and made to fit perfectly. This is a good idea in places where the undercabinet can be seen from another part of the room and the installation wants to be neat and clean. If each cover pieces are cut to the exact length necessary the individual sockets can be snapped to the track base, fit tight to the track cover on each side, and thus they are automatically spaced in exact increments . This takes careful measuring and cutting to pull off, but it is possible to do.
Pushing the lamp socket over the cable within the track the socket should be pressed down firmly until the unit seats and a snap is heard. This is to ensure a good connection. Be careful of those points, they are very sharp!
For the purpose of greater clarity, in this installation you will see the sockets and lamps from the front of the cabinet face, I will attach a cabinet rail later on which will hide these items.
Under normal circumstances, these items would be assembled behind the bottom rail of the cabinet door, while you were standing on your head, a lot like putting a radio in a '57 Chevy's dashboard! It should be clear that anything you can do before-hand to eliminate any space-time delirium while inverted, confusing left from right, up from down; that kind of thing, is very helpful. Unless you're a tree dweller!
Notice the socket has a reflector which must reflect thelamp's light back into the cabinet, don't put these in backwards, or the light would be reflected back at the cabinet rail.
For all intents and purposes, this installation will demonstrate how a china cabinet can be side-lit with this system, or a bookcase, stereo cabinet, etc.. Do you have trouble reading the label on a CD? Add Ambiance lighting to the CD cabinet and illuminate it!
These products are from Wiremold, a surface raceway system sometimes used in conjunction with the Ambinace system.
A functioning system actually roughed in by myself at another location, is presented here to illustrate a slightly different installation requirement.
the junction box, trac base, cable and a 1-hole clip are installed under a cabinet. The junction box, or splice box, is installed here to change over from a 14/3 romex cable, to Ambiance cable.
This photo shows how the trac can be bent around corners, a unique lighting scheme indeed.
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IAUL Episode I
The Ambiance lighting system is a low voltage application, in that the voltage feeding the lamps is 12 volts. Lighting can be designed for virtually any voltage (literally, too), however, normal house power for lighting use in the United States is 60 cycle / 120 volts / Alternating Current (AC). The 120 volt power source is then "transformed" to 12 volts AC, and this is accomplished through the use of, you guessed it, a Transformer!
A transformer you ask, what is that? A long story I don't want to bore you with, so the short of it is thus: A transformer is an electrical device that consists of two coils of wire, each with two "phase" conductors, or, at this juncture, simply two connection points or terminals.
A set of these phase conductors would be labled the input, or primary coil and the other the output, or secondary coil. As I obey the rules of basic electricity whilst building this device, I place the two "coils", primary and secondary in close proximity to one another, say like a pair of water wheels, side by side, immersed in a river of water.
This first coil, or water wheel, is energized (the wheel caused to move) by an infeed of electrical energy (read: water) filling successive buckets at the top of the wheel's motion, with gravity doing the rest of the work by dragging the wheel along with it as each filled and weighted bucket wends it's way to earth again @ 1-gravity.
The second wheel is without water filling it's buckets, but due to the movement of the first wheel and the current it stirs in the swirling water it rides in, the second wheel is pulled along with the first, in the same direction, perhaps with a little less energy than the original.
The first coil of wire, or waterwheel, is energized by an electrical current and a magnetic field is produced around it. If a second coil is in the same pool of weater (read: in the magnetic field of the first coil) then it, too will produce a current flow (read: wheel movement) in the second coil, perhaps with a little less energy than the original.
Enter Electrical Engineer with notebook, pencil and calculator, adjust figures to accommodate for losses in secondary coil by adjusting wire size in the coils of the primary coil. Eventually produce a "transformer" that converts the 120 volts of electrical energy we feed into the primary coil into 12 volts available at the secondary coil. Well, if you are not confused now, you will be shortly.....
So, our system uses these step-down transformers to produce the 12 volts necessary to energize the light bulbs.
I will start by identifiying the various system parts for you, and, along with photos of an actual installation, guide you through the process.
These are the individual lamp sockets for the system, the lamp installs in between the two posts in the front view (l), while you can see the two "spears" that pierce the cable and make electrical contact in the rear view. Trust me, these are very sharp and will cut your skin just as easily as it slices into the cable jacket (r).
This next view (below) shows the 2-conductor cable, inside the track assembly. The socket, shown snapped over the track section, actually helps to hold the cable in place, eliminating the need for the cover in this particular installation.
In this view notice the cable is marked in 2" intervals. The warning of using the wrong lamp in the system should be heeded also, overheating can cause fires; which is the result of using incorrectly sized lamps.
In this photo you can see the junction box, Sea Gull # 9459-15, this item is used in installations where the cable from the transformer to the track is run in a different cable type, in this case I used a piece of 14/3 non-metallic cable (romex). The splice allows me to change from one cable type to another; keeping the splice hidden behind a cover. When doing this, I consider the red and black, together as one phase; the neutral and the bare ground wire as the second phase. This allows for the use of the larger, combined conductor size of the two # 14 AWG, which can span greater distances without losing power.
The double-stick tape (sticky both sides) is very useful for fastening the track to the cabinet, but it must sometimes be supplemented with a clip, such as this use shown here.
The box, with cover is shown installed. The use of double stick tape and a one hole clip secure this set-up to the cabinet. When twisting the cable to make it fit into the track, it puts added stress on the other components, necessitating a secondary means of adhesion. There is also a short piece of track cover in use here, to further secure the cable in the track base.
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Installing Ambiance Undercabinet Lighting (IAUL)
The Ambiance undercabinet lighting components shown here are actually the parts of the undercabinet "fixture" that you will custom build in-place, in your own kitchen.
As mentioned previously, the components of the "fixture" are the transformer, trac base, trac cover, 2-conductor cable, light sockets, lamps, clips that hold the trac in place, as well as double-stick tape.
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Friday, June 17, 2005
Ambiance by Seagull Lighting
Undercabinet lighting in a kitchen can be a very effective means to light the countertop workspace. Over the past several years (13) I have been utilizing an application of undercabinet lighting system called "Ambiance", manufactured by Sea Gull Lighting; with fantastic results. I say an application of the Ambiance system, because there are many different products in the line, adaptable for a great number of uses. I will be take you through an installation of one of the systems, including track, cable, sockets, lamps and transformers, and I will be talking strictly about the undercabinet installation application amd considerations.
The Ambiance system consists of a flexible nonmetallic base trac, two wire low voltage cable, sockets that stab into the cable and snap on the track, a track cover piece and a transformer to drop the voltage from 120 volt line voltage to the 12 volts necessary to power the lamps.
The flexible track section is predrilled along it's length at six inch increments for fastening with flat head wood screws to the underside of the kitchen cabinet. This 48" trac section can be screwed in place, as mentioned, it can be adhered with two-sided tape, held in place with snap-on 1-hole clips, or a combination of all three.
The Ambiance cable, a flexible cord with two #10 AWG stranded conductors, is designed to snap into the base track and is held in place by friction, the lamp sockets and/or the snap-on track cover.
The Ambiance sockets snap onto the trac while simultaneously two very sharp angled points pierce the insulated conductors in the cable and make contact. A zenon lamp, 5 or 10 watts apiece, of very white high intensity lamp designed for the socket being used, is snapped in place.
The Ambiance trac cover can be used (or not) to hold the conductors in place, or to neaten up the work. The sockets are placed at whatever distance apart that is necessary, and in this way I will actually build the lighting fixture in-place, customizing each installation as I go.
Stay tuned for this tomorrow..
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Monday, June 13, 2005
Service Ready
Rough-In Continued
With the home runs installed, the panelboard installation is almost complete. We have the panelboard mounted in the wall, roughly 60" to the center off the finished floor. This allows for easy access to everyone for utilizing the circuit breakers when necessary, such as a problem with a tripped circuit breaker. Tripping circuit breakers due to overloaded circuits should not happen in a new house, it is the electrician’s job to ensure that overloaded circuits not occur at any time, for any reason, with the designed-in-place circuitry he crafts. But they sometimes do and for that reason, and the safety of the maintenance people, there are a whole set of do’s and do not’s for the electrical panelboard installation and related service equipment.
An area designated as space for the electrical panelboard must have these attributes:
An adequate horizontal space (side to side) of not less than 30", or 2'-6". The panelboard can be mounted anywhere within this 30" horizontal space, although in most cases it is mounted near the center of this space. Above and below the actual foot-print of the panelboard a space of 14-1/4" or greater width, by the depth of the panelboard enclosure itself (usually 3-1/2" - 4") is reserved space for the electrical wiring. In this zone, which extends from floor to structural ceiling, no other system is allowed to penetrate or pass through this space. That means no heating ducts or pipes, no plumbing pipes, no vacuum system pipes, no telephone or alarm wires, no cable tv wires, or speaker wires, notta thing, Nuttin! But that is not all.
For the safety of the installer, the maintenance people and the homeowner, working space for panelboards and other electrical device and/or equipment installation is such:
In the space from floor to structural ceiling in the area defined as 30" (2.5') wide and 36 inches (3') deep and 80" (6.5') there shall be no other obstructions to the electrician (or anyone for that matter) working on a panelboard installation. If a usable space for the panelboard is available that meets the 6.5' height clearance requirement, it is best to utilize it. NO other obstructions is a reference to any bookshelves, desks, work benches and the like, that could be built under, or around the electrical equipment. No Can Do!
The thinking is that the user, leaning over a work bench or bookcase is in peril of falling into the live electrical parts, left exposed while under going any number of electrical tasks, including testing and resetting a blown circuit breaker. The idea is to allow the person room to stand in front of the equipment without banging his head, bending over, or squatting on one knee. Logical, don’t you think?
The next item that we consider for installation on the electric service, is the device that keeps track of all of electricity you use in your household, the receptacle if you will, for the electric meter. This socket, described as having two line and two load terminal jaws, or opposing parts that close to hold fast a connection between itself and the flat spade terminals of the electric meter, and a terminal buss for the Grounded or Neutral Conductor. These meter sockets or pans as they are also known to some, are rated for voltage and amperage, for residential work the most common are 100 amp and 200 amp versions and sometimes in the bigger homes a 400 amp model.
Housed most often in a steel enclosure, usually raintight since it will be mounted on the exterior of the building, or out in the weather. Line and Load lugs (connection tabs) are mounted on an non-conductive ceramic yoke to keep them insulated from the grounded connection made at the neutral buss, which is fastened directly to the steel enclosure. The two top terminals are the Line or the street side of the electric meter, the two bottom terminals are the load side. The neutral conductors are not metered, the connection for the neutral is made on a two-terminal strip, as mentioned, which is fastened to the steel enclosure, making it part (electrically) of the grounding electrode system. For the purpose of an additional connection, there is an additional lug on the neutral buss, for the connection of the grounding electrode conductor.
Photo / Meter Socket
Since we sometimes do overhead cables to the street for power, from a telephone pole and we sometimes do underground cabling to a pole, a hand hole or transformer vault, the raintight meter enclosure must be adaptable for these two uses. Some companies make a single, overhead meter socket and sell you a blank plate to use when you are going underground and don’t need the top knockout; others make both an overhead and underground socket for each use.
In the overhead version of the socket, there is a large hole at the top of the enclosure which will have four mounting holes for the meter hub, or raintight collar; which at once closes in the gaping hole and allows a threaded hub for the insertion of a rain tight PVC connector, or terminal adapter.
I use Poly-Vinyl-Chloride (PVC) Schedule 40 conduit for all of our service installations, it allows for a better installation, with longevity in mind. Also, when you have to re-shingle, or re-side your home, the conduit is much easier and safer for the subcontractor, be they roofer, siding installer, or painter. At this point in our house, I will use the 2" PVC, Schedule 40 conduit between the panelboard, located in the laundry / back entry, to the meter socket, located on the back of the house.
The panelboard is mounted between two wall studs, on an interior partition, this mandates that I enter the enclosure from the bottom, and shoot outdoors through and within the wood stud wall, with the 2" conduit. Directly below the panelboard, I glue a male terminal adapter (fancy word for 2" PVC connector) on a 90 sweep fitting. Adding a lock nut and plastic bushing inside the enclosure I tighten fast the lock nut with a screw driver and a hammer. Turning the 90 sweep to face the opposing stud, in this case to the rright or outside of the building I mark the centerpoint of the sweep end, and bore a 2-9/16" hole. I continue boring 2-9/16" holes through adjoining studs until I reach the exterior sheathing and stop. With a smaller, 1/4" drill bit, I continue boring through the exterior sheathing and shingles or clapboard siding, until I am through all of the material. I can then locate, on the exterior, where that 1/4" bit came through, lining up a pilot bit for a 2-9/16" hole saw to continue the larger size through the last of the siding and sheathing. By doing this, we eliminate tear-out of the shingles, caused on the outside of the house from the brawn of the larger, more destructive wood-boring bit. It may be necessary to adjust the height of the horizontal holes for the conduit so that they better match the position of the hole and it’s relation to the shingle courses on the outside of the building.
All this done, we can then calculate the size of the grounding electrode conductor, and the bonding jumper for bonding; to make one - electrically, the water pipes and the electrical service ground. One conductor, the bonding jumper, must be sized in accordance with NEC rulings in relation to the size of the service entrance conductors. The Grounding Electrode Conductor is sized according to a prescribed table in alignment with the total amperage of the Electric Service.
In both cases, these cables for the ground and the bond, must be in-place in this service, because the panelboard is mounted on an inside partition and accessing it later on will not be easy, once the finish (wallboard, etc.) is applied.
In our house, for the Bonding Jumper I run a #4 stranded bare copper (as opposed to solid conductor) to a cold water pipe, and I attach it with an approved grounding clamp at the pipe and attach it to the neutral buss in the panelboard. For the Grounding Electrode conductor, because I am using two ground rods for grounding electrodes, I run a # 6 stranded bare copper and attach it to the two rods, unbroken if possible, with an acorn ground clamp and the neutral buss in the panelboard.
Photo of Ground Clamps and Ground Rods
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Friday, June 10, 2005
Winding Down The Rough In
Clean Clothes and Cooked Food
The Laundry
Since both the clothes dryer and the cooking range in our house are electric, we must run cable to these two major electric appliances. For the Electric Clothes Dryer, which utilizes a 30 amp, 120/240 volt 4-wire receptacle, we use 10/3 romex. Size 10/3 romex is a cable assembly which consists of four conductors, all # 10 American Wire Gauge (AWG); with an insulated black and a red, considered current- carrying conductors, an insulated white, or neutral conductor (the ground-ed conductor) and a bare (no insulation) ground-ing conductor, called an equipment ground, to properly ground the circuit or device.
This 10/3 cable is pulled in between the electrical panelboard in the back hall to the dryer receptacle. With the washing machine and clothes dryer inside the closet, adjacent to the panelboard, this isn’t a very long pull. The cable is run into usually a 2-gang switch box, mounted around 36" above the floor, or so as to best serve the appliance. When the appliance is set in place, a proper 30 amp 4-wire cord must be used to bring the two live conductors, the neutral, ground-ed conductor and the ground-ing or equipment ground conductor to the appliance.
Cooking for Starters
The Electric Range requires a heavier cable than the Clothes Dryer, and utilizes a 50 amp, 120/240 volt 4-wire receptacle. This is served to the appliance with an 8/3 romex cable, which like the 10/3 cable has four conductors, in this case all # 8 AWG. An insulated red and black, or current-carrying conductors, an insulated white, neutral conductor, ground-ed conductor and a ground-ing conductor, to properly ground, in this case the receptacle and subsequently the range itself.
The range cable, as it is called at this point, requires the use of larger staples to fasten it to the studs and joists and the connectors are larger where this cable terminates in a deep 4-11/16" square steel box.
It utilizes a 4-wire receptacle mounted on a raised box cover and fastened so it stands proud of the wall by the depth of the box itself (2-1/8") plus the raised cover (½") and device (1/8") and the 50 amp 4-wire cord and cap (5/8"). This assembly must be mounted so that the appliance can be plugged into the receptacle and the range itself located such that the two don’t compete with each other for space, you’ll want to make sure there is a void at the back of the range to accommodate the depth of this assembly.
Another way to accomplish the range receptacle installation is to mount a 4-wire 50 ampere surface mount self-contained receptacle, these are available for the 30 amp clothes dryer receptacle and the 50 amp electric range receptacle. Like the electric dryer receptacle, where the box is mounted inside the wall cavity, the same installation technique can be applied.
Clamping for Lack of Mobility
I will mention here that all cables entering electrical boxes; most especially steel electrical boxes, per NEC must be installed in an approved connector with a clamp and two screws to tighten down and hold fast the cable in the connector. In some cases, where the connector is larger than 3/4", a non-metallic bushing is required to further protect the cable from the chafing effects caused from a cable left loosely in the connector. The point here is that, if there is a sharp steel edge against which the cable assembly scratches, there will be physical damage inflicted upon the cable sheath and eventually cutting through the insulation and eventually (and inevitably) causing a short circuit.
A Little Vibration
I should mention that I have encountered some of these cables left in loosed connectors and found in some cases that vibration has done most of the damage. What vibration? Consider that a large truck, driving by your house, cause a rumble in the earth that you can feel, applying these same factors to the electrical box situation, you can see the problem is a very real one.
Home Runs Without Rounding the Bases
The home-run cables are all brought to the main panelboard for connection to the power source, through the eventual use of circuit breakers. Each cable must be run through an approved two-screw connector and, if the connector is 3/4" or larger, we also need to install a non-metallic bushing, over the end threads of the connector to protect the cable from chafing damage. The reason that smaller cables don’t require non-metallic bushings? The larger cables are much stiffer and weigh more and thus cause more damage when pressed against a sharp steel edge.
Once inside the panelboard, the individual conductors of the cables are separated from each other and connected to the various electrical busses. An electrical buss is basically a terminal strip, or a common place to terminate the various sized conductors, held tightly in place under set-screws.
Public Transportation It is Not
A Ground Buss is a terminal strip for the ground-ing conductors. Bare copper; sometimes with green insulation; sometimes green and yellow striped. Solid copper or stranded conductors each one is placed under a set screw and tightened down fast. Assuring the screws are turned in tight is essential to electrical safety, a loose connection causes a voltage drop, as the current flow soars conversely, overheating and arcing, or sparks caused from the “chatter” of the loose connection. This condition is the number one cause of electrical fires, through-out the world. More on that later.
A Neutral Buss is a terminal strip for the ground-ed, or neutral conductors of the 120/240 volt system. I do not understand why they do this, but the NEC does not use the term “Neutral” for the Ground-ed conductor, they simply refer to this conductor as the Gound-ed conductor. This simple lack of definition cause a great deal of confusion, even for the veterans (like me) who skim the text of a dog eared Code Book and find themselves confusing the two terms. Anyway, the neutral conductors are individually connected to the terminal strip with a single conductor, solid or stranded, each under it’s own single set-screw.
Power Please
The remainder of the conductors are the power connections to the individual circuit breakers within the panelboard. Each “circuit” has it’s own characteristics, as I have mentioned before, with each conductor size warranting it’s own properly-sized circuit breaker (over-current) device. A # 14 conductor is protected at 15 amps; #12 at 20 amps; a #10 at 30 amps, and a 38 at 50 amps, etc., etc.. Over fusing is another area that causes a great deal of confusion also, not to mention fires, but this time it is not the electrician that is mistaken, for he knows better. This time it is the unaware homeowner that does the deed (overfuses) and cause an unsafe condition, - overheated conductors causing insulation failure, or worse, and eventually a very hazardous situation for the occupants.
A 120 volt circuit, having it’s white and ground conductors connected to the neutral and ground buss, is powered by a properly sized single-pole circuit breaker. A 240 volt circuit, such as the electric range and the electric dryer we have in our house, is powered by a properly sized double-pole circuit breaker. At this stage of the job, the rough in, we are not installing circuit breakers, that will come later.
The panelboard must be covered to protect it during the construction period to keep contaminants (construction debris and water) from damaging the electrical connections and components.
We will be installing the service to this house soon, stay with us......
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Absentee Blogger
Sorry that I have been absent from this blog this month and part of last, I am busy closing down my Electrical Contracting business (Old Harbor Electric, Inc.) and taking care of loose ends. But that is all behind me now, I will have weekly entries from here on in.
DH
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Sunday, May 15, 2005
Rough Wiring III
Two Wire Cables
After the 3-wire (14/3) cables are pulled in to the various 3-way and 4-way switches, I begin with the circuit feeds and interconnecting 2-wire (14/2) cables in the circuits, running between the devices in each room. Again as you can see from the 2nd floor electrical plan, the circuits themselves contain up to nine items, or utilizations. A utilization is a place where electricity is consumed by an electrical load of some sort, a light fixture, a ceiling fan, or simply a table lamp plugged into a receptacle are examples.
Circuitry Simplified
Again, if you follow the circuitry around the 2nd floor rooms, you will see that circuit # 14 picks up the vanity light, the fan and light unit in the bathroom, then it runs to the receptacle under the window in the hall, to the 2-gang switch at the top of the stairs, where it feeds the hallway recessed lighting (note lighter circuit line from 2-gang switch to the first fixture in the hallway array).
The same 14/2 cable is then run to the front of the house, where it feeds the 2-gang box at the base of the attic stairs. This makes nine uses, or utilizations, on that particular circuit.
Circuit # 15 feeds the two receptacles in the hallway, then the ceiling fan in bedroom two, where the cable is run to the 2-gang switch just inside the bedroom door. Notice the lighter cable from the switch location to the ceiling fan, this is how the fan would actually be fed, from the switch to the fan unit. If you also notice that there is no wire depicted any longer from the 2nd switch in that 2-gang location and doesn’t have a lighter circuit line leading to an outlet or another switched device.
The reason for this is that the other plan depicted the switching arrangement, not the circuitry, the difference you ask? Simple, if you follow the lighter circuitry line from that same 2-gang box to the first receptacle, on the adjoining wall to bedroom one, you will see that it continues around the whole room and ends up feeding the switch for the closet light. Keep in mind that these are circuit lines only, and they only tell you half of the story regarding the method we use to make things work.
In every receptacle and switch box there must be at least one cable to utilize when connecting a device, this cable containing the required conductors for the use intended.
Line and Load Conductors
We have discussed using 3-wire (14/3) cable between the 3-Way and 4-Way switches, and between the smoke detectors. We haven’t discuss the other uses for this same cable; that is to carry live power and a second switched conductor within the same cable assembly.
Going to the first receptacle on the adjoining wall to bedroom once again and consider the cable (again) that runs back to the 2-gang switch box at the door. If we use a 3-wire cable (14/3) in this cable run, instead of a 14/2, we could bring to that location a constant feed conductor and a switched conductor . We could then continue to the next receptacle in bedroom two, on the same wall, with the 14/3 cable. In so doing we are able to switch those two bedroom receptacles (actually half-switched) and provide continuity for the un-switched conductor to continue around the room and activate the other devices and light fixtures.
Multiwire Branch Circuits
A third use for 14/3 romex, or any three wire non-metallic (NM) cable is to bring two separate circuits to the same location, each of theses two circuits would use the same white, or neutral conductor. Without getting too technical here, suffice it to say that the single white conductor, feeding both circuits, only carries the unbalanced load of the circuit. Un-balanced load? What does that mean?
Well, I should explain this for you in finer detail, especially since I haven’t even mentioned, as of yet, what a balanced load is, so here goes.
Balanced or Unbalanced?
A balanced load would be a circuit where the electrical load (amperes) is equal in both conductors of a 120/240 volt, three wire circuit, and where no current at all would flow in the neutral conductor. In this manner the circuit is just exactly that, a complete path for electrons to flow in a complete lap from start to finish. This balanced load would then be acting as a series circuit, using the neutral conductor of the three wire cable to complete the “circuit”, when actually it is a connection, on the neutral buss inside the panelboard that accomplishes that. The circuit would be made without drawing current from the neutral buss at all, as long as the load amperage was matched evenly on each individual conductor.
If the circuit were to become un-balanced, such as what would occur if turning off a part of that electrical load, like a single light bulb, the neutral, or white conductor, would then carry that un-balanced portion of the current. In any case the neutral will never be subject to overload, as long as the three wire circuit was connected properly at the panelboard. More on that later.
240 Volts and Cable Assemblies
To dispel a myth, although most people think you must have large cable to carry 240 volts, as if 240 volts was somehow bigger than 115 volts, this is not true, all NM sheathed cable, from 14/2 romex and up is rated for 300 volts, maximum between conductors. Large cable, with large conductors, can carry more amperage than cable with smaller conductors. This larger cable is used usually to feed an electric dryer, or electric range, where the amperage is between thirty and fifty amperes, and they both use 240 volts. Conclusion, large conductors - more amperage, small conductors - low amperage; conductor size is not a consideration when used to carry 240 volts, conductor size relates to amperage capacity of conductors in the various cable assemblies.
Home Run Is Not Just Another Baseball Term
As we near the end of the rough-in portion of this house, and before we are finished running power and lighting cables, we must install the home runs, or circuit feeds to each of these circuits. From the plan, we have circuits # 12, 14 and 15, all 14/2 cables, that must be brought down to the panelboard location, and, in this case, the main electric service equipment. Remember that the circuit feeding the bathroom outlet, # 13, must be a separate 20 amp circuit to meet NEC, so circuit it is run in 12/2 romex, to handle the higher amperage (20 amp).
Location Of Service Equipment
At some point during the siting of the house, the location of electric service to the building will have been decided upon. Factors that affect this process are then considered, the first being each particular building site and the source of electric power. Is the electric power delivered overhead on poles, or underground in trenches including the conduits, if required? Usually the decision is made to go to a particular pole, or underground connection box or transformer. Usually, but not always, the distance is the major consideration and the cost the motivating force.
Although the sight of an electric meter on the side of the house facing the street isn’t the prettiest of things, the sight of the overhead cables for cable television, telephone and power are even less inviting a sight! Therefore, asthetics does play a role in some situations. But I don’t want to wander too far off-station when I just wanted to locate the service equipment in this particular house. Once we locate the panelboard, this is to where we pull all of the cables, or home runs, from each individual branch circuit.
Knowing the panelboard location, the electrician would then determine the best route for all of these home runs. Usually a series of holes are bored above the location, in this case the service panelboard is located in the back hall, in the closet partition, facing in to the hallway.
Busy Spot That Kitchen!
Another consideration when determining the panelboard location its the proximity to the major loads. In this case the laundry, with washer and dryer are right there in the closet behind the panel location, also, the kitchen, with the various appliances and appliance circuits, is also close by. This is considered a great spot for the panel, especially in regard to cabling for the much busier kitchen area, circuits-wise (six circuits total) than any other part of the residence.
All this said, the electrician now has a “home” to go to for power for each of the individual branch circuits. From the drawing of the first floor you can see circuits #8 through #11, circuit #6 is the homerun for the required 20 amp GFCI protected receptacle at the bathroom vanity.
Telephony and Cable TV
Once the 14/2 circuits are installed, and the kitchen appliance, 12/2 or 20 amp circuits, are also pulled in to their respective locations, the cutting in and splicing of all of the cables into all of the electrical switch boxes can commence. While the electricians are doing that, I will explain the next cabling jobs we do in the home.
In 1982 or so, back when a telephone system monopoly existed in the United States, laws were passed to de-regulate the telecommunications industry, or Ma Bell - as the amalgamation - American Telegraph & Telephone was called at the time. The de-regulation itself caused a shift in policy at the old AT&T, whereas the phone workers no longer did the cabling inside the home for a new customer.
More Work For The Electricians
This work was left to us, the electricians, to perform the task of installing telephones in homes and businesses, as a part of our services. We now do all of the interior telephone system installations and the telephone company only brings the dial tone to the interface on the side of your home. This was a sort of boon for electrical contractors, but the benefit to the consumer was short-lived, as companies re-structured and got around the monopoly policies of the new system.
Today we have the same monopolies, but the telephone workers themselves are increasingly harder to find. Downsizing has caused a lot of union telephone workers, from the International Brotherhood of Electrical Workers (IBEW) to lose their jobs, oh well!
Cable Television Went The De-Regulation Route Too.
This same downsizing and restructuring has had the same effect in the cable television industry, whereas the electricians now do the in home installations, the Cable TV companies simply provide a place to connect our in-house TV system of splitters and cables and sometimes signal amplifiers for the larger installations.
That said, the cables for the telephone are now installed in the dwelling.
In the second floor bedrooms you can see the locations for the telephone, on what will be the bed wall, and the cable television outlet is across the room. Makes sense right? The phone is near you and the television is across the room?
Each telephone location is fed from the main telephone lines, called an interface, usually installed on the outside of the house, ultimately near where the power will enter the building. Each telephone has a single cable from each location to the interface, the telephone cable I have been using for twelve years is known as Category 5e. This cable assembly consists of four twisted pairs of wires, which allows the connection of up to four lines, such as a home line, a business line, a fax line, and an internet-connection line, if necessary. These “pairs” are twisted around each other at different rates, say five twists to the foot, then four twists, etc., to eliminate cross-talk between pairs. Cross-talk is the ability to hear the conversation, or conversations, of other users, on the different pairs of un-twisted conductors.
This is also true for the cable television cables, where they, too are connected to an “interface”, supplied by the service provider. Each television location is separately cabled back to the interface, where the Cable TV guys hook up our system of splitters and amplifiers.
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Wednesday, April 27, 2005
Rough Wiring II
Pulling Cables
So, with the holes all bored out in the studs, plates and shoes of the walls, it is time to actually pull in some wire. Again, on the second floor, the various cable assemblies are “run out” to speed the installation time, as well as keep the cables from twisting as we pull them through the bored holes. This is a process that can be simplified by buying an uncoiling device, such as the one in the photo, a sort of lazy susan on which the coil of non-metallic sheathed cable is placed. The cable is then threaded through the outplay arm, or bailer, to avoid tangling. The unit itself is held in place by a friction connection of two steel arms which straddle the wood framing members; actually designed for use with the vertical 2 X 4 framing studs, see photo.
Photo of Cable Reeler
While the unit splays out the cable as you pull it, the spinning motion uncoils the wire just as it was manufactured (actually in the reverse), flat, kink free, and ready for stapling neatly along the framing members. Keeping the wire straight in this manner simplifies the installation, and keeping the wire straight is a much easier task than making it straight again once you’ve tied it in a square knot! I have been asked how I am able to do such a neat job of cabling and stapling; the answer is always the same, don’t foul the line and it won’t ever need untangling. (A bit of maritime humor here, I come from a long line of fisherman, beginning in 1848, in Gloucester, Massachusetts).
Photo of Smoke Detectors, a 3-way & a 4-way Switch
3-Way Switches And Smoke Detectors
Beginning with the 14/3 cable, I will pull in the 3-way wiring for the 2nd floor hallway lighting. I drag a cable up through the bored hole above the 2-gang switch box at the end of the hallway, at the base of the stairs to the attic. Pulling across the top plate of the framed 2 X 4 wall, the cable is kept inside the framing members, woven under the ceiling joists and between the furring strips of the ceiling construction. Once the cable is pulled across the hallway, it is then routed in a manner parallel to the joists, above the furring strips, to the area above the electrical box for a 4-Way switch. The 4-Way switch, which is part of the upper hall switching system, is located between the two bedroom doors. It is then pushed down through the bored hole above the switch box, gathering enough wire to reach the switch box, plus an extra 12 - 14" of slack. To prevent pull back of the cable it is stapled to the wood stud, just below ceiling height. The cable is then neatly stapled parallel along the ceiling joist until it reaches the crossing point in the hallway. It is then stapled across the underside of the joists, to the location above the initial 3-Way switch. The cable can then be pulled back taut and cut to length, leaving 12 - 14" of extra cable.
This done, a second 14/3 is pushed up through the bored hole above the same 4-Way switch and it is led down the hallway, over the furring strips toward the bathroom, until it reaches a point across the hallway from the 2-Gang switch box. From there it is woven under the ceiling joists and pulled down through on of the bored holes in the wall plate above it. Leaving the appropriate amount of slack, the cable is then cut off and it is stapled back to the stud, again just below the ceiling level, to prevent pull back. Stapling the cable to the underside of the ceiling joists, the cable pulled taut as I go across the hallway, for neatness. I finish stapling the cable parallel to the joists down the hall and back to the 4-Way switch box. These cable staples are the insulated variety, so as not to damage the cable. These are staples we are driving here, not railroad spikes, we don’t drive them in so far that they cut into the cable (I’ve seen apprentices do this).
I am not going to demonstrate the installation of each cable in this way, but you get the idea that this is the way to run cable, parallel to the framing members where possible, following the contour of the object being traversed, crossing at right angles otherwise. Always follow this method, keeping the cables parallel to the members and stapled back, away from the finished surface by 1-1/4", per NEC rules. For cabling in basements, running across ceiling joists is limited to # 6 AWG or larger (the smallest allowable size / conductors in the cable).
Photo, 2nd floor circuits
If I show you the 2nd floor circuit layout, you can see how we might feed the various devices. The single, darker lines between items depicts a 14/2 cable, as it enters, and sometimes also leave each electrical box, at every duplex receptacle location, as well as some of the switch boxes. No, these items are not wired like the old Christmas tree lights - where if one lamp goes out - they all go out, that would be a series circuit. These various electrical load devices (light bulbs in lamps plugged into wall receptacles) are wired in parallel, but they are none the less on the same circuit! If the circuit breaker trips, or if a fuse blows, the entire circuit will go off (eight or ten electrical items) and nothing will work.
Trouble Shooting With Ease
A key factor to understand and consider when doing your own electrical system work, and that is the fact that every wire, connection or device is part of a larger schematic diagram. Therefore if any of these elements fail to perform, the electrician may have to search through every electrical box, checking splices and such - while trying to troubleshoot, and therefore it sometimes does take some time to determine the source any problem. Believe me, for a professional like myself, finding trouble in a circuit that has been tampered with, either by the homeowner or an otherwise inexperienced person, is up there with the most time consuming and frustrating of endeavors! Nothing that the novice has done makes any sense to the pro, not the order, the method or the end result.
Existing Electric Wiring & Remodeling Or Renovation
You should consider that the licensed electrician responsible for the existing wiring in your house probably knew what he was doing and interconnected the various electrical elements according to accepted codes and practices, at least those codes that were in-force at the time of the initial installation. (most licensed electricians are well qualified, no matter how immensely unsung their feats; the least of which include hazard and intrigue) Therefore, the electrical cables running in between the studs and joist of your home, are a portion of those many circuits.
Interrupted Circuits
When a renovation project requires that a new window or a new door (or the old in a new location) be installed, a cable or series of cables might be found in the wall cavity in which the new opening is to be located. They might be serving other needs besides those in that particular room; the found cables could run to the 2nd floor, the basement, or elsewhere in the building. Interrupting the circuits (severing any cables) would cause the loss of power to all or some of the devices and/or utilizations that are a portions of any particular circuit. For this reason, remodeling or renovation electrical work is more costly than similar tasks being performed on new buildings; especially while under construction.
Feed Through Devices
In a duplex receptacle location, the conductors are connected to the duplex receptacle on one set of terminal screws (black to brass & white to silver) and fed out of the receptacle on the other set of terminal screws, these receptacles are therefore connected in parallel and are known as feed-through devices. There is a “tab” connecting the two screw terminal screws to each other; break off that tab, the connection is broken, and the device ceases to feed out to the next receptacle or electrical device. We use this broken tab feature to enable a switched receptacle, and, when necessary, the feed-through feature is accomplished with a splice and pigtail.
Switches And Their Place In The Home
Switches are housed in electrical boxes from 1-Gang to 4-Gang or 5-Gang and sometimes larger. The switched loads, or lighting fixtures, can be supplied with power through a number of configurations; in the case of a 3-Way system, at the first or second 3-Way switch location, or even at the fixture itself.
Back to the 2nd Floor plan again, where circuit 14 is routed to the 2-Gang box at the vanity where it powers the vanity fixture and the 14/2 is spliced-through to the 2-Gang switch box inside the bathroom door, where it powers the fan / light unit; on to the 2-Gang switch box at the top of the stairway, where it powers the upper hallway lights, and, finally, to the 2-Gang switch box at the base of the attic stairs.
Follow circuit 12, as it first hits the 2-Gang switch box inside the door in bedroom one. In this switch box is the load wire out to the bedroom ceiling fan as well as a line wire out to the 1-Gang switch box, a load wire out to the fluorescent closet fixture, a line wire out to the bedroom receptacle, and so on.
The cables we have just pulled-in to the multitudinous switch and receptacle locations now serve as the network for the next step in wiring the building, entering the cables into the boxes and connecting the circuit conductors, the switch loads, the 3-Way switch travelers, the Single Pole switch returns, the switch legs, comes right now.
A Bunch Of Spaghetti You Say?
As any good electrician should do, I have labeled the cables as I pulled them in to their sundry locations; through way too many bored holes. One at a time the cables are neatly stapled down the stud, with insulated staples, keeping the cables away from the finish side of the stud and out of harms way; kept from impalement by drywall screws, or picture-hanging nails.
Stripped Of Their Dignity
One by one, the cables are stripped of their outer jacket, untwisted and disentangled from the various nonconductive packing materials or components, and pushed in to the plastic, knock out cable entries available on plastic switch boxes. The cables are usually entered into the multi-gang switch box in the actual location where the switch is to be; that is, if the cable was for the first light in the room, the cable would enter into the 1st “box” or “ganged” location, if there were a 3-Way switch location, both cables would end up in the same box or “gang”. I usually would mark the load from these switch locations to ease identifying them later. The various conductors of these cables would be spliced together, starting with the grounding conductors. In the plastic box we would have to provide a pigtail to be connected to the ground screw on the device, for grounding purposes, therefore the two copper conductors from the two cables and a third, loose conductor, suitably long for the job, are twisted together, in a clockwise direction, an appropriately sized wire nut would be threaded on and the whole thing pushed to the back of the box. The next conductors to tackle would be the neutrals, or white conductors. The whites are gathered together, and one by one they are bundled together neatly, formed so as to facilitate conforming them to the shape of the ganged switch box most efficiently. They are stripped to their proper length for splicing, twisted together, a wire nut installed and the whole thing folded back neatly into the box. The conductors that will be affixed to switch terminals are pushed aside; the remaining black, sometimes red conductors will then be spliced together in the same manner and, if need be, pigtailed for use to power a device or multiple devices. At the rough-in stage, the individual conductors are wrapped to one another, to label, or distinguish, the use of a Single Pole, 3-Way or 4-Way Switch, and pushed back into the box.
Repetition Is The Answer
This method is repeated time and again, for circuit after circuit until the whole house is interconnected and ready for inspection by the Local Authority Having Jurisdiction, or, perhaps more succinct, the local Inspector Of Wires.
All of the homeruns (branch circuits)are pulled in to the location of the panelboard for connection for power.
At this time however, the rest of the cables can be routed throughout the structure, for cable television, maybe a satellite dish, telephone locations, including both desk and wall mount phones. Or, these days, maybe a network for the Personal Computer users in the house, an ethernet system for a home office, fax lines, etc., etc..
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Rough Wiring I
Once The Walk Through Is Over And Done With
With the Walk-Through complete, the final layout of the electrical system can begin, even if there are a few details to iron out. At this point the rough-in wiring of the house’s electrical systems can begin.
On Your Mark, Get Set, Wire! I always start my wiring jobs in the area the furthest away from the electrical panelboard, from which all the electrical feeders and branch circuits within the house will originate. If there is a sub-main panel board, this is where some of the branch circuits will originate; a sub-main feeder from the panelboard supplies power to it.
Remember these words "feeder" and "branch circuit", they are very important, distinctive and descriptive words. The definition of a feeder is: All circuit conductors between the service equipment, the source of the separately derived system, or other power supply source and the branch-circuit overcurrent device. The definition of a branch circuit is: The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
There are also several types of branch circuits within a dwelling, or for that matter in any building being wired.
An Appliance branch circuit is one that supplies energy to one or more outlets to which appliances will be connected and has no permanently connected luminaires (light fixtures) that are not part of an appliance. A branch circuit supplies two or more receptacles or outlets for lighting and appliances.
An Individual branch circuit that supplies only one utilization equipment. A Multi-Wire branch circuit consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of that system.
A large building may have a main service panelboard and a sub-main panelboard at a different location, as part of the electrical distribution system. Some of the largest buildings will have many feeders and sub-main panelboards, spread throughout the building. In this way, all of the circuits (home runs) do not have to originate in the same panelboard. Our small house, has only the main service panelboard, where each and every circuit in the building will originate.
In this view of the 2nd floor, you can see the “circuit cable” feeding power to the actual devices and lighting switches by following the darker lines running between the individual units. The lighter lines you see run from smoke detector to smoke detectors, is actually the cable powering and interconnecting to each of them at once. Some of the lighter lines from switches to various devices represent the uses of the circuit, such as bedroom fans, hallway lights, etc.
Bath GFCI Receptacle. Notice that Circuit # 13 feeds the GFCI receptacle in the bathroom, and per NEC will be served with 120 volts, 20 amperes.
Bedroom Circuits And Smoke Detectors
Circuit # 12 is for receptacles and fan, as well as the closet light and receptacles in Bedroom One, but, can you also see the heavy line to the smoke detector, from that same bedroom circuit? That is the “power feed” for the detector system. This is a common way to feed the smoke alarm system, in that the fire detection system is required to be fed from a lighting circuit, instead of a circuit alone and by itself. The thinking behind this rule is, if the homeowner, tenant, or occupant wants to turn the smoke detectors off, they must also have the inconvenience of losing a lighting circuit. In this way the homeowner isn't as liable to turn the smoke detectors off and leave them off indefinitely. So, in this case bedroom one is the master bedroom and, if circuit 12 were turned off, there would be no power in that master bedroom, no fan, no lights, no television, nothing but darkness. Get the point? In most cases the detector can be taken down by the homeowner and reset, you'll see how shortly.
Battery Back-Up
These days the smoke detectors we install are self-contained, with battery back-up. This is an excellent way to ensure fire detection coverage even when the power is off! But, the batteries don't last forever, so if your own smoke detector in your present home is chirping at you, it is usually, but not always, an indication that the battery needs to be replaced.
It is always recommended that you replace all of the batteries in all of the detectors at the same time. Ergo, if one battery is dead the others can't be far behind. Local weathermen usually insist we check our smoke detectors batteries each time we toggle between Standard Time and Daylight Saving Time, in the Spring and Fall. What is that, Fall down Spring up, no, Spring forward, Fall over, or is it Fall back, Spring forward? Whatever, remember to change the batteries in your smoke detectors!
Each of these smoke detectors has to be hard-wired together, or daisy-chained, so that they alarm in tandem with one another; so if one goes off, eventually they all will go into alarm mode and nearly shatter your eardrums at a sound level of at least 8.5 decibels, the minimum required audio level. Okay, so it won't shatter your eardrums, but it certainly will wake you up!
Re-Setting A Smoke Detector that Has Gone Into Alarm. To clear a smoke detector that is in alarm; that is not involved with a fire, simply turn off the circuit that is feeding it for several moments. Allow the smoke chamber to clear, and, via the printed circuit board, reset itself. If when the circuit is re-energized, the detectors still will not reset, it may be that one or more of them are dirty, contaminated, or simply have an insect crawling inside them (a common problem).
Placement Of Detectors
Notice the lighter lines (representing cables) connecting the smoke detectors in the bedrooms, hallway at the base of the attic stairs and on up to the attic, if a detector is required there in your town. From the light switch, there is a cable for the attic light. Note also that the other end of the smoke detector system the cable heads down the stairway to the first floor detector, mounted on the ceiling near the bottom of the stairs A Little Physics LessonIt is common knowledge that hot air rises, as does the smoke from that incendiary source. Therefore the smoke detector at the ceiling of the lower level, near the base of the stairwell will be activated by the smoke wending its way to the second floor. This smoke, heated from the fire, rises to the ceiling and once there, spreads laterally across the ceiling. At the point where the ceiling meets the wall, there is what is known as a dead zone, in regard to the smoke and the now-heated ambient air. This "dead" zone doesn't allow the air currents to reach all the way into the corner, therefore it is best to mount the detectors at a minimum of 12" away from adjoining walls, and, for cathedral ceilings, three feet down from the highest point. The same law of physics applies here, in that eventually the super-heated air will fill the airspace at the roof peak, and actually block out the smoke, rendering a detector mounted at that level useless. Cleaning Smoke Detectors Cleaning smoke detectors is a project you, the homeowner, can do yourself. It is always best to take the detectors down on at a time. They all unscrew or twist counter-clockwise from there ceiling mount and unplug from the power source, with a safe and easy to operate plug mechanism. Use a vacuum cleaner to either blow or suck the dust or bugs out of the unit. Once cleaned, reconnect the plug and reinstall them as they were previous. Once all detectors are installed, the Smoke Detectors must be tested for functionality. Somewhere on the face of each detector there is a small push button for testing the detector. Pushing this test button should activate the smoke detector in your hand first; holding the button down until you can hear all of them chime in together is a simple way to ensure your family's protection from a fire. Releasing the button will allow the detectors to recover by opening up a relay in the detector itself; it may take several minutes before they are completely silent.
The building department, or fire inspector, will schedule an actual fire test, by introducing smoke directly to the smoke detector with a smoking torch. He will then check that all of the detectors are ringing, as is the code.
The electricians begin on the second floor, by first nailing all of the electrical boxes in their respective receptacle and switch locations as per the electrical plan (e-plan). From the e-plan can be identified all of the elements included, and these elements are then transcribed to the wall studs of the building, usually with a felt tip pen. The electrician would go around and mark an S1, S3or S4 on the stud closest to where each item, the switch, light or receptacle, would be mounted. Remember that we are talking about wood studs and that these are usually set at 16" on center and our 'locationing' is limited somewhat by support members that cannot be drilled through, chiseled into, or removed entirely.
Receptacles can be mounted at virtually any height, but, to comply with NEC an outlet must be mounted below 5'-6" to be considered a required receptacle. Receptacles serving the kitchen countertop, a bathroom vanity, or wet bars can be a maximum of 18" above the counter, vanity or wetbar to be the required receptacle. That said, we follow these general rules, but we all (each individual electrician) have our own heights for these different units.
Hammer Height?
In new construction, I ask the guys to mount the receptacles at 14" to 16" above rough floor, or hammer-height, as long as the installer use the same hammer in each room, of each house, bar none.
Hammer-height is achieved by placing the box against the stud we are mounting the electrical box to, lining up the depth of the wall covering with the gauge that is etched on each individual box. By laying the hammer head on the floor, with the handle held vertically against the chosen stud, the box can be set atop the handle for the height. Each hammer manufacturers length varies by an inch or so, from tool to tool, but they are all roughly 14 - 15" long. Switch boxes I like to mount at 42" above the rough floor, or 41-3/4" above the finish floor. This may vary from room to room, to accommodate special wall treatments like wainscoting, beaded paneling, or some other architectural feature that must be recognized and reconciled into the placement of these devices. Some designers and architects will make there electrician line up the elements that he/she installs, for example switches aligned one above the other, fixtures and smoke detectors in the center of the hallways, etc..
If we are doing a remodeling job, or partial renovation, I try to match the existing switch heights within the original structure. As to the receptacles, they can also be mounted in the baseboard, or mockboards, to remain unseen as they perform their function for compliance and convenience. Or, they can be mounted to match the existing detail of the building being remodeled. Telephone, Cable TV, and Data locations can follow the receptacles and be mounted at so called hammer-height, or be in the baseboard. In the kitchen, they can be mounted at the counter top height, matching the switch height for general congruity, or you can have a wall-hung telephone, mounted at 60 or so inches above the floor, 24" above the counter top. As with most everything else these days, telephones are cordless, everyone uses answering machines, and, if you have a data line you have a PC; therefore, it is a good idea to place these data, telephone and catv outlets next to a duplex receptacle, or, in the alternative, place a duplex receptacle next to them!
After the rooms are marked out for the boxes, and the boxes are all hung, 1-gang for the receptacles, some 2-gang boxes, as well as some 3 or 4-gang boxes for the switches. The rooms are then drilled-out for the non-metallic cable (romex) that will course through, between and behind the buildings inner sanctum; the framing and finish construction components. Usually a single hole is drilled above every single switch or receptacle box (1-gang), two holes for a double switch box (2-gang), etc. If some of the switch and outlet locations are accessible laterally, through the adjoining studs of a wall, we drill horizontally only when it makes sense to do so. No matter how the wall and ceiling members are drilled out, each hole must occupy the center of the framing member being drilled through. Also, when stapling the romex, the cable must not ever be closer to the finish side of the wall than 3/4". These rules are an effort to prevent a cable or group of cables being pierced by a nail or a drywall screw. In the case where the wire is run closer than these guidelines, a metal plate must be used, of at least a 1/16" thickness, to prevent this hazard. Remember, that if a nail or screw pierces the cable, and doesn't trip the circuit breaker, that nail head or screw head is now electrically alive. If you were to paint over a screw that is so-energized, especially with latex, water-based paint, you would recieve a small shock. I know this first hand!
The electrician and his apprentice continue to mount electrical boxes, for the various devices, switches, receptacles and light fixtures. The second floor has the recessed lights in the hallway, a fan & light unit in the bathroom, one closet fluorescent in each bedroom closet and the smoke detectors.
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Click On Plan To Enlarge
Once the switch boxes, recessed lighting frames, ceiling boxes and smoke detector boxes are all mounted, and the holes are bored throughout, the electricians will then start to pull in some of the cables for the connection of the various elements that comprise the electrical system. So, as they prepare to pull the circuits, switch legs, light returns, cabling for the smoke detectors and 3-Way light switching systems, I will explain the tasks at hand in more detail.
Before I go there though, I should explain to you the cable assemblies themselves, how they are constructed; what they are designed to do. This is a many faceted subject, that I will explain here briefly, as well as make other references and add further explanations of their make-up and uses for you, as we go along.
American Wire Gauge, or AWG, is a standard for conductor size, adopted as American Standard early in the developmental stage of wire and cable manufacturing. For all intents and purposes, we will be talking mainly about the following AWG sizes in the residential wiring sphere, I will list them by size and briefly explain the uses of each. Keep in mind that the lower the number, the thicker the AWG size and the higher the amperage they can carry. For the intention of this article, only copper conductors are being discussed, unless stated otherwise.
Thermostat wire, or low voltage control wire, comes in both 18 and 20 gauge, with configurations of up to 8 multiple conductors. An 18 gauge, two conductor cable is expressed as 18/2; a 20 gauge, three conductor cable is expressed as 20/3, etc. Ergo, gauge / conductors. As the name implies, these cables are used for thermostats and controls such as garage door openers, doorbells and buttons, furnace wiring, zone valves and dampers, among other uses. Thermostat wire can be used for voltages up to 300 volts (between conductors), but generally in the uses mentioned they carry only 16 volts for your door chimes; or up to 24 volts for your heating or cooling thermostat. Non-metallic sheathed cable (romex) is available in gauges from 14 to 2, with configurations of up to 4 multiple conductors, plus a grounding conductor. A 14 gauge, two conductor cable is expressed as 14/2 Romex; a 2 gauge, three conductor cable is expressed 2/3 Romex. Not expressed, but none the less included in the cable, is the grounding conductor. These cables can be used to wire receptacles, lights, switches, small appliances, etc., mostly used in wood frame construction. Service Entrance Cable (SEU) or (SER), comes in gauges from 10 to 4/0, in configurations of up to 4 multiple conductors, and a grounding conductor. A 10 gauge, two conductor cable is expressed 10/2 SE; a 10 gauge, three conductor cable is expressed as 10/3 SER. . The 2-conductor cable is called SE cable, for Service Entrance, the 3 or 4-conductor cable is called SER cable, for Service Entrance, Round. The 2-conductor is more or less flat, or oval cable, and the SER is round. These cables are used excusively for service entrance conductors, usually installed from your electric metering equipment to your panel board. SE cables can also have aluminum conductors; they are also sunlight resistant. Metal Clad, (MC) cable is available in gauges from 14 to 2, in configurations of up to four conductors plus a grounding conductor. A 2 gauge, three conductor cable is expressed as 2/3 MC cable; a 12 gauge, 2-conductor cable is expressed as 12/2 MC cable. The sheath is made of either steel, or aluminum. MC cable is used in rough service areas, where a flexible cable is preferred, on heating and cooling equipment and controls. Underground Feeder, (UF) cable is available in gauges from 14 to 2, with configurations up to four conductors and a ground conductor. A two conductor 14 gauge cable is expressed as 14/2 UF, etc. UF cable is used in direct burial conditions, for post lights, ground lights, for feeders and branch circuits; UF cable, like SE cable is also sunlight resistantAll of the cables above are constructed similarly, with the insulated conductors and the uninsulated ground conductor sheathed in an outer wrapping of plastic, aluminum or steel (MC cable).
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Wednesday, April 06, 2005
An Electrician's Walk-Through
Ironing Out The Details
If you were wondering - what if the owner wants a special recessed light fixture, or two light fixtures at the front door instead or the one I specified? At this point in time, the reason for the walk-through for the electrical work becomes crystal clear, and that is to give the customer, or homeowner, an opportunity to fine-tune the various elements in their new home, item by item. Just as you would have control of the paint colors of the various rooms, walls and trim paint for example, the plumbing fixtures in the bath and kitchen, etc., likewise you do have control of the electrical elements. If you are building a custom home, or even buying so-called spec house (being built on the speculation that it can be sold) you may be able to catch a builder with a house in-the-works such that you can have control over some of these selections.
When you think about it, is the telephone in your present home in a good location, or would it work better if it were somewhere else? How about the cable tv outlet, is it in a good spot, or would it be much more convenient in a different area? Maybe the phone location in a home isn’t as important these days as it once was, but nonetheless there are considerations for that even now; with cordless and cellular phones. In this day and age, all telephones need power sources in the home for a cordless or cellular telephone, for recharging or for powering an answering machine. As you can see, there are a lot of little decisions you can make at this stage of the game, that will help or hinder you for years to come.
The homeowner arrives and we begin by looking at the floor plan that I had marked out and discussing the job I had done making decisions for them (even though they weren’t factored-in with the design equation) basically finding out what were there likes and dislikes.
I ask them questions like:
1. Are they accustomed to their new spaces?
2. Have they taken time to locate or arrange their for example?
3. Do they have concepts regarding how they will utilize the various spaces?
4. Can I help them in presenting the variables on any given electrical item?
5. Do they have any previous knowledge about this process, or anything related to electrical, from a previous project?
6. Have they given thought to the various elements that we will be discussing for installation?
In this view of the 2nd floor, complete with smoke detectors, telephones and cable television outlets, you can see all the switching arrangement for the spaces. I have labeled the switches at each location, if not designated w/ 3 or 4, assume others are single-pole switches.
I mentioned that electricians have to be home traffic consultants to do their job well in the residential marketplace. Which way will you likely turn when you come in the back door into the kitchen, O.K., assuming you are not carrying groceries? Would you likely to cross the room to the hallway, to the bathroom, or the right to go up the stairs to the second floor? What about when you were carrying groceries, which way would you turn to off-load them, to the right to the pantry, or into the kitchen first? If you were coming down from the second floor where would you most likely head when you got to the bottom of the stairs? My vote? Probably the kitchen, to start the coffee. Which way do you open the basement door, away from the kitchen so you have to walk around the door, or toward the kitchen, where you will more likely be coming from. Electricians’ know these things, because it’s their job!
Once the customer shares their thoughts and I get a basic feel for the items that they may want to include for installation in regard to electrical items, I give them a basic course in National Electrical Code (NEC), or at least information relative to the residential installation at hand.
Wall Switches
I tell them that at every entry door to the house I need to have at least two switches, one for the exterior light on the porch for example, and one for the interior kitchen light. The idea here is that you would leave your house and turn the outdoor light on as you left, conversely turning off the kitchen light behind you as you leave the room. By NEC dictum this switching arrangement occurs every time you enter and exit a room, for example leaving the kitchen and going down the hallway to another part of the front door. As you left the kitchen you would turn the kitchen light off at one of the three switches that are at the start of the hallway. The second and third switches would be to turn on the light(s) of the room you were entering, in this case the back or the front hallway.
So, you have a switch inside your bedroom, and one in the hallway outside your room, for the hallway lighting for example. This arrangement is typical, in that it satisfies the lighted-way code issue by providing access to a switch to control the lights in the hallway with the hall switch, and have a switch inside the room to that now lighted-way. What if you don’t have a light in a bedroom you say? Well the NEC provides for that also by allowing us to switch a portion of a duplex receptacle, for example the lower half. Usually a lamp is plugged into the switched ‘half’ of the receptacle and the lamp itself is left ‘on’. Follow the lines from the bedroom switches, to the receptacles in each adjoining wall of the two bedrooms. In each of these bedrooms there are two receptacles switched by the door. I will go into more wiring detail about this in a How To” segment in later entries.
This switch ruling is actually enforced as a building code issue, as a lighted-way is a safe way, and adhered to in this case by the electrician, a typical crossover of National Building Code and National Electrical Code. So that covers the switching ‘have to’s’, but let me go on with a little more of this switching stuff, before I walk out and leave the kitchen light burning!
The Gamut On Switches
The Single Pole Switch
Ah, switches; there are several to choose from, starting with the Single Pole Switch. The Single Pole switch has two terminals and the toggle action of the switch closes and opens a circuit that it is controlling (turns on the light, turns off the light).
The 2-Pole Switch
The 2-Pole Switch is used in applications where it is necessary to break two poles or phases of power. These are used when a 240 volt circuit, like a water pump, or an electric heater, must be disconnected from its source of power. These are not found in your home as wall switches, but they may be used in your basement, or in your workshop. A 2-Pole switch, a term interchangeable with Double Pole switch, make and break two phases, and therefore has an ON and OFF written on the toggle handle; the switch should always be mounted so that you can read the words.
The 3-Way Switch
This name of this switch, a 3-Way, sort of suggests switches in three locations for the same light switch, but the expression is actually a misnomer. A 3-way switch allows the user to control a particular light fixture, or half-switched receptacle, from two locations, as in the switching configurations I mentioned, passing from one area to the other, throwing the light off behind you as you turn the lights on ahead of you. The 3-Way switch has three screw terminals, with one of these three terminal as a pivot point; the flipping action toggles between the other two terminals. The 3-Way switch has nothing written on the toggle handle, and can be mounted in any manner, since there is no top, no bottom, and no OFF position on a 3-Way switch
The 4-Way Switch
Not to add confusion, but there is also a 4-way switch, which by its name implies switching at a fourth location, but that is only half-true. Although you can use this 4-way switch as the fourth switch for a given light fixture, you can also use this switch as the third switch, the fourth and then the fifth switch, a sixth switch, etc., with one, two, or three 4-way switches wired in between the two 3-ways in the system.
The 4-Way Switch has four terminal screws, for the connection of four conductors, two from each cable assembly. The flipping action toggles the connection between two red conductors, one from each cable, with the connection of two black conductors. So sometimes the switch will be connecting red / red, black / black; other times black / red and black / red. The 4-Way switch does not have anything written on the toggle handle and can be mounted in any manner, since there is no top, no bottom, since there is no OFF position on a 4-Way switch.
You would also see this switching system in common stairways of multiple storied buildings, and mandatory for the lighting within such stairwells, whereby anyone entering the stairway from any level, can turn the lights on when they enter the space. So, that covers wall switches and NEC issues, are you still with me?
Duplex Receptacles
Good, let us now move on to another electrical element that must be installed in a concise and consistent manner, that is the convenience outlet, or duplex receptacle. These are the electrical units that will eliminate the need for extension cords, keeping your home free of hazards involving an overloaded and overheated extension cord. There are strict rules as to the minimum requirements for the installation of these power sources; but you can always add more than the NEC requires.
I just did hit on a major reason for the need for plenty of duplex receptacles, to eliminate the need for extension cords, both for the overheating hazard as mentioned, but further, considering the physical presence of extension cords, running under the rug; scary means necessary to getting power to that lamp, window air conditioner, fan, curling iron or hair dryer.. ...whatever! Extension cords are bad news and they shouldn’t be used to keep the electrician away. Because faulty extension cords are still the leading cause of house fires; the NEC has made a change recently about the safety of extension cords and what is now required to eliminate that fire hazard. Read more on “Arc Fault Protection” in future entries.
Receptacles Where?
NEC reads that every wall space larger than 24" wide, or that short section of wall between two closet or bedroom doors, measuring 24" or more, requires a duplex receptacle.
Now suppose that there was a closet, or a bathroom door, adjacent to the entry door to the bedroom, and, if the width between the two doors was 24" or greater, there would be a NEC requirement for a duplex receptacle to cover that space. If the space was less than 24" wide, a receptacle would not be required. Now we come to the other side of the closet door, as the wall continues along, enclosing the room. Measuring from the further edge of that door to the first receptacle the distance must be no greater than six feet, measured along the wall surface; from that receptacle the spacing to the next receptacle must be no longer than 12 feet, and, again measured along the wall surface.
The receptacle spacing in the kitchen, bathroom, hallways and foyers differs slightly, as the various rooms are treated not dissimilarly, since they have specific uses, and specific requirements, and the NEC is tailored to address those inherent electrical power needs and the hazards they bring into being. We spoke earlier in the conversation about providing GFCI protection in kitchens, bathrooms, unfinished basements and outdoors. See our kitchen plan below.
Notice the receptacles are spaced 2' from the sink edge, and 4' in between them; this is the code requirement for receptacles on kitchen counter tops. The reason is a pretty clear one, there are a lot of electrical appliances these days, and the lot of them come with only 2' cords, see the need? Also these days there is a new feature on kitchen countertops, and that is the so-called appliance garage, yes, appliance garage. These cabinets are brought down all the way to the counter top, and with a duplex receptacle or two inside them, the individual appliances can be used outside the garage, without unplugging them. The remaing counter top area must still be wired with duplex receptacles, as before, with the same stated distances. I include the following plan to demonstrate receptacle spacing on the kitchen counter top.
I will touch on the exterior receptacle requirements here and mention that in the receptacle count for the dwelling, by NEC rules I have to provide a weather-resistant duplex receptacle at the front and rear of any dwelling unit, and there must be one mounted at each grade level in the building. If there was a walkout room in your basement, which delivered you to a different grade on your property, you would be required to add a weather-resistant GFCI receptacle at that grade level. Also, the idea from the Code Making Panel, as to what hazardous situation you are trying to prevent, is the convenience of running an extension cord through the door or window and plugging into a receptacle that is not GFCI protected. This would leave the user in peril in regard to protection from electrocution.
Walk On
I always start walking through the house with a client by suggesting we start at the second floor, or the furthest reaches of the structure, and work our way out to daylight and the lower floors. By doing this I can often walk the person or persons through as if they were getting out of bed and beginning their day.
Being on the upper floors, I usually find a bedroom to begin the tour. For the homeowner it is usually best to know the spaces beforehand, the window placement, possible furniture layout like locating the bed wall, and where the dressers will be. The switch at the door can control a receptacle in the room, one conveniently located behind a dresser is usually the place for the lamp that will be activated by the switch, you choose. A Cable Television outlet can be mounted opposite the bed, and a telephone outlet can be located on a bedside table, with a telephone jack behind the bed.
I usually don’t recommend any light fixtures in the bedroom ceilings, since that was a practice that went out of favor years ago, but, although I don’t promote bedroom lighting, others do like them. A recessed over each headboard for reading, or sometimes swing-arm lamps are utilized, I recommend that the light fixtures be switched at the lamp, and not at the switch by the door. Overhead lighting for reading can also be a disaster, I should mention that you would get glare off the page that you wouldn’t be able to direct, making reading uncomfortable in bed, not to mention reflected light on your sleeping partner.
Closet Lights A Must
The two bedrooms in this view also feature closet lighting, restricted to fluorescent lighting strips, open lamp or housed within a plastic lens; open lamps of the incandescent type are no longer legal. The problem with the open lamp of yesteryear is the excessive heat created by the lamp; when considering the fire hazard of an over-filled closet, teeming with items, stacked high, touching the hot surface of the lamp. So it goes that the next thing you know, there is fire.
Ceiling Fans In Summer
Also in the bedrooms you will see ceiling, or paddle fans. Ceiling fans are used the world over, most especially in the warmer climate zones. Moving the air around, ever so lightly on a hot evening, cools the body down nicely, without air conditioning. Although in these Northern climes, when sitting around the woodstove, or fireplace, which is commonplace come Autumn, you wouldn't use the ceiling fan to recirculate the warm air, as most people assume. In fact, the moving air serves only to cool your body down, while evaporating moisture from your skin. The very perception of losing body heat in this way in Winter boggles the mind, but it's true! Keep in mind that a ceiling fan must be hung at a maximum height, usually 7'-6" above the finish floor from the lowest point of the fan blade in order to pass code. If the fan manufacturer says that you can hang their fan at a lower height, you may do so. Underwriters Laboratory (U.L.) sets the standard as the manufacturer's recommendations for use, always follow the guidelines that come with an electrical product. It is the law!
End Bedroom Befuddlment
In a bedroom I ask the client if they have a habit of reading before it’s “lights out”. If so, the swing arm lamps I mentioned earlier would be suggested now, and I would also give them a little idea that works for some people. It has to do with the switch at the door, controlling one or more of the outlets in the bedroom. If the answer is yes, they do read before retiring at night, I will suggest that we use the switch at the bedroom door to control the receptacle(s) behind the bed, switching only half of the device. The swing arm lamps can be plugged into these switched outlets, but what then? We have all had the problem, and that is what do you do every time you want to use the switch at the door to turn on your swing arm lamps, and the lamps are still turned off, as you left them the night before. I suggest to them that we install two 3-Way switches and a 4-Way switch in the room in stead of the single switch at the door, now you have three places to control these lamps, one at the door, one at each night stand. Leave the swing arm lamps in the “on” position and use the wall switches to control the lamps! Or, if there is only one reader in the house, you can put in two 3-Way switches, with one 3-Way switch behind the reader’s night table and one at the door! Now I have to know who sleeps on what side of the bed! Yikes!
Bathroom Solutions
Inside our bathroom, there is a small vanity cabinet, with a sink, a full fiberglass bathtub unit and a toilet. I generally recommend a switch, just inside the door, for a light source. The light source can be a ceiling light, either recessed or surface mount. Whatever is chosen, it should be placed near the center of the room, for general illumination, as shown. Another bathroom lighting option is that the required exhaust fan can also be combined with a light fixture, a unit called, not surprisingly, a fan/light! More on that below. In this house, the 2nd floor bathroom has a recessed light over the toilet area, this light is shown switched with the light portion of the fan/light unit, but it could warrant a separate switch.
At the sink, or vanity, I suggest using sconce fixtures, usually two mounted at an average height, somewhere between 60" or 72", depending on personal preferences. The object of these additional light fixtures is to provide ample light at the vanity sink. Men will use the additional light for shaving, women for putting on makeup. A single fixture could be mounted above the mirror or medicine cabinet; you probably have seen multi-lamp varieties; some would use or suggest an overhead recessed or surface lighting scheme, but this arrangement would cause facial shadowing and, I think Martha Stewart would agree, that is not a Good Thing! In order to make an accurate decision as to the location of these sconce fixtures we leave a cable inside the wall cavity, to be pulled out of the wall later on, when the vanity sink, the vanity mirror or the medicine cabinet are installed, when we can pinpoint the location of the two fixtures. I will get into that wiring procedure in a future blog, with a hands-on rough wiring segment. As to the switch location for the vanity fixtures I always suggest we put the switch at the vanity location.
Bathroom Exhaust Fans A Must!
I tell the client that they must have an exhaust fan in every bathroom space, regardless of whether or not there is an operational window in the room. The first question from a customer is always, can we have a separate switch for the fan? The answer of course, is yes; there is only the need for the exhaust fan, even if it's on a separate switch. As far as I know there are no exhaust fan police to arrest you, or your child, for not utilizing it!
There are myriad choices in the fan, or fan/light market, all with different configurations of air movers, light sources; types, not to mention the ultra-quiet models. And, since a bath exhaust fan can sound much like the clatter of an approaching freight train, the whisper quiet models get the most consideration these days. I sometimes suggest a fan/light unit and mount it within the bathtub enclosure, where it can light an otherwise dark area and immediately exhaust the moist air from your hot shower.
In the quiet division, there are now available so-called remote located, multi-space ventilating fans, or single source, multi-station intake/exhaust fan systems. but, whatever moniker they carry, the concept is to remove the sound source as far from the ventilated space as possible, with a fan motor actually installed in your attic, or crawl space, the single fan can serve one or more bathrooms. The individual rooms are connected, with wye fittings and flexible duct hose, to ceiling intake vents and dampered exhaust caps on the exterior of the building. These fans are available in several sizes, with their uptake/output measured in Cubic Feet Per Minute (CFM), according to the size (cubic feet) of the room(s) being ventilated. No matter what the situation, there are building codes which must be followed that mention minimum air movement, this is expressed in air changes per hour. The object of the building code and the practicality of a system to exhaust odors and humidity is a simple one -more air movement - less mildew and mold. Clearly a health issue.
As shown, this 2nd floor bathroom gets a fan/light combination, and, getting back to the separate switch for the bath fan, yes, we can put in that separate switch, but, since the fan should be used when showering, it is utilized most effectively if turned on before you start your shower, and turned off fifteen minutes after you turn off the shower. I usually recommend a timer, a simple spring wind-up type. They fit in the box like a switch, you can set it for 10 - 15 - 20 minutes, towel off, and walk away! The unit shuts down for you in the desired time frame, keeping your room's air quality in the fresh and healthy zone. My clients with children breathe a sigh of relief when they hear this solution!
Required Ground Fault Receptacles
Then there is the bathroom receptacle, which must be accessible to the sink area, or vanity top. This receptacle must be a GFCI receptacle, and, if a new house, it be on a 120 volt 20 amp circuit, that said, the same individual 120 volt circuit can service all of the bath receptacles in the house, although your electrician might find this troublesome from an economical standpoint. If the budget allows, I suggest the use of multiple GFCI devices, protecting each location. This method is the most convenient for the end-user, since when the individual device trips, the reset button is easy to find. The GFCI is almost always ganged together with the vanity light switch, at least on my watch! Make sure you have plenty of “receptacles” into which to plug all of your bath appliances, electric toothbrush, hair dryer or curler, a night light?
Out in the hallway, but still on the second floor, we discuss the lighting possibilities for the upper hall area, and lighting in the stairs down to the first floor. If there is a hall closet, the ceiling light source can be located nearby. Locating the stairwell light fixture so it not only lights the steps, but does so without creating too many shadows.
Hallways and Corridors
In this plan of the 2nd floor hallway and the lighting locations; in this case the hall fixtures are recessed. There are also three duplex receptacles, only one is required by the NEC. In some cases these hallway outlets can serve as a power source for a lamp, perhaps on a small table. It makes sense to place the required duplex so that it could serve that purpose, by placing it where there is adequate space. Other receptacles in hallways can be utilized when vacuuming, or using some other household appliance. In some older residences, where there are no hall outlets, the outlets are often hidden behind furniture and not exactly accessible.
Now, as we are about to turn off the lights in the upper hall, you will see another switch that will light your way to the bottom of the stairs, flip it on the way by.
1st Floor Switching and Power Plan
The Foyer, Or Entry Hall
As you came down the stairs you would turn off the stairwell lighting with the 3-Way switch at the bottom of the stairs, next to the window. The switch for the lighting in the back hallway, is one of the two 3-Way switches is at the front door. Some would want a second switch at the bottom of the stairs, to control those recessed lights, but, the owner decided they didn’t mind the reach. I think it is fine the way it is, only an arms length away. The front entry, or foyer, is lit by the array of recessed lighting, heading to the back of the house and the kitchen. Chosen for these locations were 5" incandescent recessed fixtures. Corridor receptacles are practically non-existent, save the one at the base of the stairs, where there may be room there for a small table under the window.
In some homes, the front foyer is the centerpiece of the house, where guest are greeted. A suitably elegant fixture could be chosen for this space, to accentuate an architectural detail, or merely blend with its surroundings.
bloghouse 1/2 bath
The Half-Bath
Inside the bathroom are two switches at the door for the exhaust fan and the general illumination is provided by the same overhead location, as part of the fan light unit. There is the required GFCI receptacle, to the right of the sink (some items have been hidden for clarity) and a switch for the single fixture over the mirror, as this one is shown. I will try to talk them out of the single fixture, we’ll see.... I will instruct the guys to leave a cable in the wall cavity, as always, so that two fixtures can be mounted exactly where they belong, measured off the mirror or medicine cabinet, once they are hung..
The Laundry
In the back hall, or laundry, the double duplex receptacle in the small coset is set in behind the washing machine and clothes dryer, a stack unit; two outlets for two appliances. If this were an electric clothes dryer, there would be a 30 amp / 240 volt circuit, just for the dryer, but in this case the clothes dryer is a gas appliance. The general area is lit by the ceiling light, but the owner wanted an extra fixture to light the area in front of the laundry. Notice th