FLOOR OUTLETS

Floor outlets are electrical outlets that are installed into a floor area rather than into a wall. Often, a floor outlet will be equipped with a metal plate to protect the outlet and wiring, along with a cover that prevents dust and other material from collecting in the outlet when the device is not in use. Outlets of this type are usually found in dens and living rooms of homes, as well as in conference rooms or other larger gathering areas in offices and public buildings.As with any type of outlet, the floor outlet is intended to allow easy access to electrical current. Because the plug can be placed at any point along the floor, it is possible to strategically position several outlets within a space, creating easy access to electricity even when a power source is needed somewhere other than along a wall. When not in use, covers snap or slide into place in order to protect the outlets and also to allow the floor to retain a smooth surface.

Beneath the surface of the floor, the configuration of the floor outlet is similar to that of a standard wall outlet. The plugs are housed in an outlet box and normally connected to a central junction box that helps regulate electric power flow. Wiring runs from the outlet box to the central junction in the same manner that electrical wiring runs through walls to a central power source.While it is possible to use plastic or porcelain plates with a floor outlet, the general recommendation is to utilize metal plates. Durable metal is much less likely to be damaged if the outlet is stepped on when not in use. The metal covers can hold up well to a lot of weight, which will help to keep the general appearance of the outlet simple and clean. When necessary, the metal plates can be outfitted with covers that are spring loaded to snap closed when the outlets are not in use.In terms of function and appearance, a floor outlet can be helpful in many situations. In a conference room, an outlet in the floor under the conference table makes it much easier to plug in audio visual equipment without running extension cords to a wall outlet. In the home, the presence of a floor outlet in the living room aids in arranging the furnishings, since major seating areas do not have to remain near a wall in order to include the presence of accent lamps in the grouping.

Installing a floor outlet is very similar to the installation of a wall outlet. As with any type of electrical wiring project, it is recommended that the installation only be conducted by a properly certified electrician.

Floor Outlet Covers on wiseGEEK: Floor outlets are electrical outlets that are installed into a floor area rather than into a wall.

Typically, a spring-loaded door covers each plug contained on the outlet unit, making it easy to seal off access to each plug when the outlet is not in use.

Stumped by the Code? Using Floor Receptacles and Wall Outlet Requirements, Placing Receptacles on Countertops, and MoreDec 18, 2012

by Mike HoltNEC Trainer / Consultant, Mike Holt Enterprises

822 Articles

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COMMENTS 1Your most pressing National Electrical Code (NEC) questions answered

 

All questions and answers are based on the 2011 NEC.

Q. What are the Code rules for using floor receptacles to meet the

receptacle wall outlet requirements in a dwelling wall space?

A.Floor receptacle outlets are not counted as the required receptacle wall

outlet, if they are located more than

18 in. from the wall [210.52(A)(3)].

 

Q. What are the NEC rules on placing receptacles for countertops in a

dwelling unit kitchen?

A.A receptacle outlet must be installed for each kitchen and dining area

countertop wall space 1 ft or wider, and receptacles must be placed so that no

point along the countertop wall space is more than 2 ft (measured horizontally)

from a receptacle outlet [210.52(C)(1)].

Exception: A receptacle outlet isn’t required on a wall directly behind a range,

counter-mounted cooking unit, or sink, in accordance with Fig. 210.52(C)(1) in

the NEC, as shown in Fig. 1.

Fig. 1. Don’t space out when determining the receptacle locations in a kitchen space.

If the countertop space behind a range or sink is larger than the dimensions

noted in Figure 210.52(C)(1) of the NEC, then a GFCI-protected receptacle

must be installed in that space. This is because, for all practical purposes, if

there is sufficient space for an appliance, then an appliance will be placed

there.

At least one receptacle outlet must be installed at each island countertop space

with a long dimension of 2 ft or more, and a short dimension of 1 ft or more

[210.52(C)(2)].

At least one receptacle outlet must be installed at each peninsular countertop

with a long dimension of 2 ft or more, and a short dimension of 1 ft or more,

measured from the connecting edge [210.52(C)(3)].

The Code does not require more than one receptacle outlet in an island or

peninsular countertop space, regardless of the length of the countertop, unless

the countertop is broken, as described in 210.52(C)(4).

When breaks occur in countertop spaces for range tops, refrigerators, or sinks,

each countertop space is considered as a separate countertop for determining

receptacle placement [210.52(C)(4)].

If a range, counter-mounted cooking unit, or sink is installed in an island or

peninsular countertop, and the depth of the counter behind the range, counter-

mounted cooking unit, or sink is less than 12 in., the countertop space is

considered to be two separate countertop spaces.

GFCI protection is required for all 15A and 20A, 125V receptacles that supply

kitchen countertop surfaces [210.8(A)(6)].

Receptacle outlets required by 210.52(C)(1) for the countertop space must be

located on or above (but not more than 20 in. above) the countertop surface.

Receptacle outlet assemblies listed for the application can be installed in

countertops [210.52(C)(5)].

Note:Receptacles must not be installed in a face-up position in countertops or

similar work surface areas in a dwelling unit [406.5(E)].

Exception: The receptacle outlet for the countertop space can be installed

below the countertop only for construction for the physically impaired or when

wall space or a backsplash is not available, such as in an island or peninsular

counter. Under these conditions, the required receptacle(s) must be located no

more than 1 ft below the countertop surface and no more than 6 in. from the

countertop edge, measured horizontally.

Receptacle outlets rendered not readily accessible by appliances fastened in

place, located in an appliance garage, behind sinks, or rangetops [210.52(C)(1)

Ex], or supplying appliances that occupy dedicated space don’t count as the

required countertop receptacles.

An “appliance garage” is an enclosed area on the countertop where an

appliance can be stored and hidden from view when not in use. If a receptacle

is installed inside an appliance garage, then it doesn’t count as a required

countertop receptacle outlet.

 

Q. What is the Code rule for mixing conductors of different systems in

the same raceway, cable, or enclosure?

A.Power conductors of alternating-current and direct-current systems rated

600V or less can occupy the same raceway, cable, or enclosure, if all

conductors have an insulation voltage rating not less than the maximum circuit

voltage [300.3(C)(1)], as shown in Fig 2.

Fig. 2. Conductors of different systems can occupy the same raceway, cable, or enclosure if the insulation voltage rating is not less than the maximum circuit voltage.

Control, signal, and communications wiring must be separated from power and

lighting circuits so the higher-voltage conductors don’t accidentally energize

the control, signal, or communications wiring:

• CATV coaxial cable [820.133(A)]

• Class 1 [725.48]

• Class 2 and Class 3 control circuits [725.136(A)]

• Communications circuits [800.133(A)(1)(c)]

• Fire alarm circuits [760.136(A)]

• Instrumentation tray cable [727.5]

•  Sound circuits [640.9(C)]

Class 1 circuit conductors can be installed with associated power conductors

[725.48(B)(1)], if all conductors have an insulation voltage rating not less than

the maximum circuit voltage [300.3(C)(1)].

A Class 2 circuit that’s been reclassified as a Class 1 circuit [725.130(A) Ex 2]

can be installed with associated power conductors [725.48(B)(1)], if all

conductors have an insulation voltage rating not less than the maximum circuit

voltage [300.3(C)(1)].

PV system conductors, both direct current and alternating current, are

permitted to be installed in the same raceways, outlet and junction boxes, or

similar fittings with each other, but they must be kept entirely independent of

all other non-PV system wiring [300.3(C)(1) Note 2 and 690.4(B)].

 

Q. What are the GFCI protection requirements for a receptacle installed

in a non-dwelling location if it is under a counter with a sink above it?

A.All 15A and 20A, 125V receptacles installed within 6 ft of the outside edge of

a sink in non-dwelling occupancies must be GFCI protected [210.8(B)(5)].

Exception No. 1: In industrial laboratories, receptacles used to supply

equipment where removal of power would introduce a greater hazard aren’t

required to be GFCI protected.

Exception No. 2: Receptacles located in patient bed locations of general care

or critical care areas of health care facilities are not required to be GFCI-

protected.

 

Q. How does the Code address the spread of fire or products of

combustion in regard to fire-rated assemblies?

A.Electrical circuits and equipment must be installed in such a way that the

spread of fire or products of combustion won’t be substantially increased.

Openings into or through fire-rated walls, floors, and ceilings for electrical

equipment must be fire-stopped using methods approved by the authority

having jurisdiction (AHJ) to maintain the fire-resistance rating of the fire-rated

assembly [300.21].

Fire-stopping materials are listed for the specific types of wiring methods and

the construction of the assembly that they penetrate.

Directories of electrical construction materials published by qualified testing

laboratories contain listing and installation restrictions necessary to maintain

the fire-resistive rating of assemblies. Outlet boxes must have a horizontal

separation not less than 24 in. when installed in a fire-rated assembly, unless

an outlet box is listed for closer spacing or protected by fire-resistant “putty

pads” in accordance with manufacturers’ instructions.

Boxes installed in fire-resistance-rated assemblies must be listed for the

purpose. If steel boxes are used, then they must be secured to the framing

member, so cut-in-type boxes aren’t permitted (UL White Book,Guide

Information for Electrical

Equipment,www.ul.com/regulators/2008_WhiteBook.pdf).

This rule also applies to control, signaling, and communications cables or

raceways:

• CATV [820.26]

• Communications [800.26]

• Control and signaling [725.25]

• Fire alarm [760.3(A)]

• Optical fiber [770.26]

• Sound systems [640.3(A)]     

How to Install a Floor OutletSay goodbye to hazardous extension cords Print Share:

     

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Step-by-Step Tools & Materials

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Sometimes electricity is just not where you need it, especially in big rooms and in older houses. A floor outlet may be the perfect way to solve the problem.

By the DIY experts of The Family Handyman Magazine

Step-by-Step

Put an outlet where you need it

Until someone comes up with a better idea, we're stuck with plugging lamps into outlets to get light. But what if you want a lamp in the middle of the room where there's no outlet? You don't have to resort to ugly and dangerous extension cords. We'll show you how easy it is to put the power where you need it by installing a handsome, stampede-proof, moisture-proof outlet in your floor (assuming your floor's not concrete!).

Cutting in and mounting the steel outlet box is a job anyone with basic carpentry skills can handle. Connecting the power is a little trickier because it requires you to locate a suitable circuit and make electrical connections. If you're uncertain how to do it, consult a basic house wiring book or a local electrician for help.

Before starting any electrical work, contact your electrical inspections department for a permit. A permit fee is a small price to pay for the assurance that the wiring is safe, and you might even get some free advice from the inspector. (See Top 10 Electrical Mistakes to see some common mistakes to avoid.)

Besides basic tools like a hammer, tape measure and screwdrivers, you'll need a drill and a 3/32-in. bit, 3/8-in. and 5/8-in. spade bits and a jigsaw. You'll also need a needle-nose pliers, a pocketknife or utility knife, a wire stripper and a voltage tester.

CAUTION!

If you're pulling power from an existing junction box or receptacle, check the color of the bare wire ends. If they're gray rather than dull brown, they're made of aluminum rather than copper. Call in a licensed electrician to connect the old aluminum wires to the new copper wires.

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Buy a special floor assembly – a regular wall outlet won't do

Photo 1: Find a location

Measure from a reference point, such as the radiator heating pipes shown, to locate the floor outlet so it falls between the 2x10 floor joists. Then use an 8-in. straight length of clothes hanger, snipped off at an angle to form a point, as a locator bit. Start the drill slowly while holding the hanger to keep it from whipping around as you drill through the flooring.

The National Electrical Code requires floor outlets to be a part of an approved assembly consisting of a metal box, gasket seal, special receptacle and strong cover plate with a moisture-proof cover. You can't just mount a regular wall outlet in the floor. The first time someone stepped on it, it would break. Besides, mopping a floor around an outlet that doesn't have a moisture-proof cover could cause corroded connections, or worse, give you a lethal shock.

The residential floor box assembly we're using may be available at home centers, but if you can't find one there, you'll find a selection at a local electrical supply store that caters to professionals. You can find aTamper Resistant Receptacle Floor Box Kit online, available through our affiliation with Amazon.com.

In addition to the floor box assembly, buy enough cable to connect the outlet to the power source. With a few local exceptions, you can use plastic-sheathed cable (technically called Type NM-B). Use 14-gauge wire if the circuit you're connecting to is protected with a 15-amp fuse or circuit breaker (12-gauge wire for 20-amp circuits).

You'll also need at least one plastic cable clamp (Photo 6), wire connectors (Photo 10), 1/2-in. plastic staples (Photo 10) and 1/2-in. x No. 4 flathead screws.

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Pick a location you can reach with the power cable

Photo 3: Cut a hole for the box

Outline the outlet box on the floor. Drill two 3/8-in. holes at the corners where the screws protrude from the sides of the metal box and two more where the outlet mounting screws go. Now use a jigsaw with a wood-cutting blade to complete the box cutout. Apply masking tape to protect the floor finish.

You can put a floor outlet anywhere, but getting the cable there can be tough. So keep routing problems in mind when you choose a location. Floors over unfinished basements or crawlspaces are easy to reach from below. Concrete floors are tougher because you have to cut a trench to the nearest power source. Floors with a finished ceiling below present a challenge that can usually be overcome with some ingenuity. SeeFishing Electrical Wire for details on how to pull cable through finished walls and ceilings.

Locate the floor joists before you cut the outlet hole. Use heat vents, cable or plumbing pipes that penetrate the floor and are visible from below as reference points. Drill a small hole through the floor (Photo 1) where you intend to place the outlet and locate the bit from the open ceiling below. If you drilled directly over a joist, you won't be able to see the bit. Move over a few inches and try again. Patch the misplaced hole in the floor with matching wood putty. We used a cut-off clothes hanger as a drill bit because it's cheap, handy and easy to spot from below. This homemade clothes hanger bit is a must for carpeted floors because the smooth sides won't catch the carpet fibers like a regular drill bit.

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Find a circuit to supply power

Photo 5: Run the cable

Run plastic-sheathed cable from the floor outlet to the power source. See the guidelines in the next step for drilling and stapling the cable.

Most open ceilings have light-fixture boxes and metal or plastic junction boxes where a number of cables are joined. Both offer potential sources of power for your floor outlet, but a ceiling light box like the one shown (Photo 9) that's switched with a pull chain rather than a wall switch is most likely to contain “hot” wires suitable for connecting the floor outlet.

Turn off the circuit breaker or unscrew the fuse that controls the circuit you've chosen. If your light fixture box is like ours, just turn on the light and have a helper watch it as you switch off the circuit breakers one at a time until the light goes out. Leave this circuit breaker switched off.

If the electrical junction box you've picked doesn't have a light fixture, you'll have to use a voltage tester to determine which circuit breaker or fuse to turn off. This process can be complex. If you don't have electrical experience or are unsure how to do this, don't hesitate to enlist the help of a licensed electrician.

A word of warning is in order here. Some electrical boxes contain more than one circuit. Before doing any work in the box, test all the wires in a box with a simple neon voltage tester (Photo 9) to make sure they're “dead.”

The electrical code requires two additional steps to ensure safety:

1. Determine if the circuit you want to use can handle the additional outlet without overloading. Do this by shutting off the circuit at the main panel. Then go through the house turning on lights and other electrical items. Add up the wattage for everything that doesn't go on, including things that are normally plugged in, such as stereos and televisions. Then add the wattage of the lamp you'll be plugging into the floor outlet. The National Electrical Code (NEC) allows a total of 1,800 watts for a 15-amp circuit; 2,400 for a 20-amp circuit. The amp rating of the circuit is printed on the circuit breaker or fuse. If the total wattage exceeds these amounts, you'll have to find a new circuit. Also, as a rule of thumb, don't use a circuit if it has any device drawing more than 7.5 amps either plugged in or directly wired to it.

2. To figure out if there's enough space in the box for the minimum box size required by the NEC, add: 1 for each hot and neutral wire entering the box, 1 for all the ground wires combined, 1 for all the clamps combined, and 2 for each device (switch or receptacle) installed in the box. Multiply this figure by 2 for 14-gauge wire and 2.25 for 12-gauge wire to get the minimum box volume in cubic inches. Plastic boxes have their volume stamped inside. Steel box capacities are listed in the electrical code. Call the electrical inspector for that information. If the box you want to use isn't big enough, add a box extension or replace the box with a larger one. For more information on sizing an electrical circuit, seePreventing Electrical Overloads.

CAUTION!

The electrical code prohibits any connections to “dedicated” circuits, such as 20-amp small-appliance circuits in kitchens and dining areas, 20-amp laundry circuits and 20-amp bathroom circuits. If you're unsure about your circuit, ask the electrical inspector.

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A first-rate electrical job mostly means getting the details right

Photo 7: Wire the receptacle

Snip off the wires so they're at least 6 in. long and protrude from the top of the metal box at least 3 in. Strip 5/8 in. of insulation from the black and white wires with a wire stripper. Connect the bare ground wire to the metal box by looping it once in a clockwise direction around the green grounding screw and tightening the screw. Loop the end of the same bare grounding wire clockwise around the grounding screw on the receptacle and tighten the screw. Connect the black wire to the brass screw and the white wire to the silver screw.

Photos 2, 3 and 4 show how to cut in and install the steel outlet box that's included with the floor outlet assembly. Mount the box. Then run the cable from your power source to the floor outlet.

Follow these rules if you have to drill through joists.

Avoid drilling holes in the center one-third of the span or length of the floor joist. Holes must be a minimum of 2 in. from the top and bottom edge of the joist. Staple the

cable with special 1/2-in. plastic NM cable staples every 4-1/2 ft. where it runs along the joist. (TIP: For a neater, easier job, unroll the cable and remove the twists before installing it.) Don't staple either end of the cable yet, and leave at least 1 ft. of extra cable on each end.

Photos 6 – 8 show how to wire the new outlet. For more information, see How to Make Safe Wire Connections.

When the floor outlet connections are complete, move to the basement and connect the other end of the wires to the power in the ceiling box (Photos 9 and 10). You'll have to remove a “knockout” plug with a screwdriver or needle-nose pliers to provide a hole for the cable to enter the box. Attach the cable to the box with a cable clamp. Many boxes have built-in clamps. Connect the wires as shown in Photo 10. Match the wire connectors you're using to the number of wires being connected. Red connectors like the ones we're using can usually connect up to five 14-gauge or four 12-gauge wires, but check the manufacturer's specifications on the package to be sure. Replace the light fixture or cover plate to complete the wiring job.

For outlet installations on carpeted floors, the top edge of the outlet box must be flush with the carpet. Flipping the outlet ears over before mounting the box is one easy way to accomplish this.

Your new floor outlet is strong enough to withstand occasional abuse, and with the cover and gaskets in place you'll be able to damp-mop the floor without worrying about getting shocked or damaging the wiring. Keep a record of the manufacturer's name in case you lose the cover and have to order a new one.

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Tools & Materials

Required Tools for this ProjectHave the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

Cordless drill 4-in-1 screwdriver Needle-nose pliers Drill bit set Jigsaw Voltage tester Non-contact voltage tester Utility knife Wire stripper/cutter Wood chisel

Required Materials for this ProjectAvoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

Electrical cable Metal coat hanger Floor box assembly Plastic cable clamps Wire connectors Plastic staples No. 4 x 1/2-in. flathead screws