Common Wiring Methods Used Concerning Wiring a Dwelling (NEC 1999) — Self Help and More

Common Wiring Methods Used Concerning Wiring a Dwelling (NEC 1999)



Upon entering your home, and in preparation of wiring your structure you should first mark out your switches and receptacle placement that you desire and that is required to meet the minimum safety standards of the NEC. This section is for marking the receptacles in living areas. Take a tape measure, with a friend, and measure from the end of a wall to 6′ along the wall, from an opening [doorway ] and then measure 12′ from that receptacle to the next receptacle as long as that wall is unbroken by an opening [doorway ] in the wall.210/52/A/1

Now continue measuring until you have reached the end of that unbroken wall. You must make sure that the last receptacle marked, is within 6′; of the end of that unbroken wall. As you measure, the required distances, you should mark, with an ink pen, on the stud, and at eye level with an R, for reference only, not height. This R marking will represent the need for a receptacle at that point, but will not represent the height that you will mark later with a measuring stick. Watch out for any obstructions such as windows going down to the floor, or doors, or cold air ducts, or a bad place to get a wire to that position, as you mark for receptacles [you may wire crossways only <perpendicular > but not long ways <parallel > through a cold air duct ]. 300/22/C/Exception You must not place a receptacle or switch in a cold or hot air duct.

If you hit an obstruction [examples are a doorway, window installed ceiling to floor, or built in cabinet ] back up to the nearest convenient position on the wall that a receptacle can be easily mounted. You must then measure 6′ [from the other side of the obstruction or break in the wall the same as it was a new wall ] to the next receptacle that is required, and repeat this process until you reach another door, or the end of the wall. Keep in mind that what you are doing is setting these receptacles so that you will not be beyond the maximum Code distances allowed, between the end of the wall [6′] and between each receptacle [12′], in the living areas. Living areas are as listed but not limited to, a living room, a bedroom, a dining room, the kitchen area that is not over a counter area, a den, a residential office, a play room, an enclosed sun room, etc. 210/52/A Remember that a garage, a laundry, a utility room, a hallway, a closet, or a foyer are not considered living areas and are not required to be included in the 6′ / 12′ rule. In these nonliving areas receptacles are installed in an as needed bases.

The Code requires that no wall [ in a living area ], over 2′; long, can be without a receptacle. 210/52/A [with the exception of behind a door or in a non-living area such as a hallway ], and any wall must have a receptacle within 6 of the end of the wall [including doorways, to be considered as an end of the wall ], and the distance being no more than 12′ between any two receptacles along an unbroken wall. Remember that in areas such as lofts, that have a long railing, half walls, etc. has the same requirements as a full size wall. 210/52/2/C These type walls may be served with a surface mounted receptacle mounted on a post or an approved floor receptacle as long as the floor receptacle is located within 18 of the wall or railing. 210/52/3 Each receptacle will serve 6′ each direction from itself. Two receptacles 12′ apart will serve 6′ each, towards each other, fulfilling the 12′ allowance to be covered by both receptacles. Rooms such as garages, laundries, utility rooms, etc. are exempt from the 6’/12′ rule. These non living area style rooms are considered work areas and not living areas. 210/52/A through H

The 6’/12′ rule is intended for the wiring design of receptacles along all walls within the living areas to be within 6′ of any lamp, television, radio, etc. You should find that all apparatuses designed for living areas that you may buy will have a 6′ cord. [designed for a light duty and low amp usage ] You should also find that all small appliances designed for the cooking areas [small appliance branch circuits] that you may buy will have a 2′ cord. [designed for a heavy duty higher amp usage ] Now you should be able to see the intent of the master designs in the whole picture for safety, as per the NEC minimum safety standards.



Next in preparation to wiring your structure, you should nail on one example of the following boxes, to set up a measuring stick for production purposes. I would nail these example boxes onto the wall at the height suggested, [as accepted practice, <Code mute on height of receptacles and switches > ]. A switch box 48 [in the living areas ], a receptacle box 12 [in a living area ], a receptacle box, or switch box, to be used over a counter 42 [in a kitchen counter area ], a washer, or dryer receptacle box 36 [in a laundry area, to be installed behind an appliance ]. These suggested heights are designed to be measured at the bottom of the box, from the floor to the box. All of these example boxes should be at the height that you prefer, just stay uniform with other boxes, of the same usage design. The above suggested heights can be changed to meet your desires, just stay uniform to avoid a roller coaster look on the finished product. A variation shows up on the finished product and then you would get to look at that misplaced receptacle or switch for the life of the structure.

In the past, some electricians used the following as a personal rule; hammer height, chest height, eye level, etc. These are not normally accurate, and will usually show uneven boxes, throughout the structure, for the finished product.

I suggest that you make a measuring stick using the above mentioned example boxes in order to set up this measuring stick for use in measuring the rest of your dwelling. Material such as a 2 X 2 board or even smaller in diameter about six feet tall should work fine as a measuring stick. Set the new measuring stick next to the first example box that you nailed on. Be sure to set the stick on the bottom plate of the wall, not the sub-floor. The subfloor may not be level, and this sub floor may change, as you move through the dwelling, thus, changing the height of the boxes. The change in height can happen, without you noticing the uneven boxes, until it is too late! While making the stick, mark a line on the measuring stick with a fine line pen or pencil for accuracy, so that it is even with the top of the example box that you just nailed up. Write above that line, on your measuring stick, identifying the intended usage of that box that the line represents with an R for a receptacle, or an S for a switch, or a T for a thermostat, etc. The reason for marking the top of the box on the measuring stick and onto the stud where a box is to be nailed is so that the line set that you marked is more easily seen while nailing on the boxes. Now proceed to mark the measuring stick with the height of the rest of the sample boxes that you nailed on previously.

You have now made a measuring stick to mark the box heights for the rest of the boxes to be installed throughout the remainder of your dwelling. You will refer to these markings after you mark the studs throughout your dwelling, reminding you as to where, and how high each box is designed to be installed, and their designed usage, later in your wiring procedures.


The kitchen is special pertaining to the maximum allowed distances between counter receptacles. They are as follows; The sink, refrigerator, oven, and cooking range will break the counter creating a new [end of counter ], the same as a doorway in the living area. 210/52/C To start marking your counter receptacles you should measure from the end of the counter that you are going to start measuring and then measure along the counter to reach 24 and mark a receptacle. Then measure a distance of no more that 48 to the next receptacle, and continue marking the counter receptacles at a maximum distance between receptacles at 48 unless you reach a stove, refrigerator, oven, or sink that breaks the counter area. If you reach one of these mentioned appliances you must then start over with the 24, because the appliance made a new end of the counter. Remember to look back to make sure that your last receptacle that you marked is within 24 of the end of the counter that you just encountered. Now look for any counter space that is less than 24 but more than 12 and also mark a receptacle over this counter space. 210-52-C-1 Each counter space wider than 12 must have a receptacle serving that counter area. 210/52/C/1

Next watch for a peninsula, or island.

The peninsula or island must have a receptacle serving any and all counter space that has a short dimension of 12 or greater and a long dimension of 24 or greater. 210/52/C

Peninsula counter spaces 210/52/C/3

If any peninsula is shorter than 24 inches from the connecting counters edge to end of counter <24 from the front of the adjoining counter to the end of the peninsula>, or if the peninsula is shorter than 12 in width from the front to rear or the counter. then a receptacle is not required to serve that peninsula .

Remember that both the width and the length of the peninsula counter space must exceed the minimum measurements before a receptacle is required

If the total length of the peninsula counter area is 24 or longer from the connecting counters edge, — and - if the peninsula is 12, or wider, in width from the front to rear of the peninsula counter area. then at least one receptacle is required to serve the entire area of this peninsula counter space. If an appliance or sink breaks that counter area then you would have two counter areas, each area having to meet the minimum length of 24″ and width of 12″ before a receptacle must serve either counter area made by that appliance or sink that split that peninsula or island into two separately treated counter areas. Each side of that appliance or sink are considered stand alone counter areas. If either separated counter area is 24″ long and 12″ wide then a receptacle must serve that separated counter area. If that separated counter area does not meet both minimum length requirement of 24″ long and 12″ wide by itself then a receptacle does not have to serve that separated counter area.

Remember that both measurements [width and length ] must be more than the minimums before a receptacle is required to serve that counter space of the peninsula.

Remember that any peninsula counter space can be as wide or as long as it wants to be with only one receptacle required to serve that unbroken peninsula counter space

Island counter spaces 210/52/C/2

Island counters spaces are treated the same as the peninsula counter space except that they are measured from end to end instead of from any connecting counters edge.

Remember that any appliance installed in the island counter creates two island spaces that are treated, separately, as two islands. These separate islands must have their own measurement which exceeds the 12 width and 24 length minimums before a receptacle is required.

Remember that any island counter space can be as wide or as long as it wants to be with only one receptacle required to serve that unbroken island counter space

More rules of receptacle installation serving a counter space 210/52/C/5

A receptacle must be installed above the counter space but not over 18 above the counter space. No receptacle is allowed to be installed in a face up position in or on a countertop. Receptacles that are behind an appliance or otherwise made not readily accessible can not serve the counter space as a required counter receptacle. 210/52/C/5

If your counter space is flat and there is no place to install a receptacle over the counter, a receptacle may be installed below the counter area with intent to serve a counter top requirement but only if the counter top is flat with no back splash or walls connected to the counter top, and no cabinet within 18 above the counter that a receptacle may be mounted under that cabinet and within that 18 limit. This receptacle below the counter area can only serve as the required receptacle serving the counter area, if it is installed not more than 12 below the counter top surface and only if the counter top does not extend more than 6 beyond the supporting cabinet base. 210/52/C/5 Exc.

Special Note Many AHJs feel that there is an inherit danger when a receptacle is mounted in the wall of a base cabinet below the counter surface. If you would plug an electric skillet, etc. on the counter area into a receptacle mounted in the wall of the base cabinet there would be a danger to small children. This danger is felt to be present even if the receptacle is mounted below the counter and within the maximum distance of 12 from the counter top. A small child can play with that skillet, or other appliance. cord and pull this hot appliance, and its ingredients, down on his or her head which could cause a severe injury due to burning of their skin. I have drawn some alternative option examples that should meet the minimum safety standards set forth by the National Electrical Code. 210/52/C/5 Exc.

Examples of some alternative options for installing a receptacle serving as a required counter receptacle

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