Height & spacing of electrical receptacles or "outlets" FAQsL

Frequently-asked questions about the proper height, spacing, and clearance distances for electrical receptacles commonly also referred to as wall plugs or electrical outlets.

This article series gives the requirements for electrical receptacle (outlet or wall plug) spacing, height, and clearances in buildings, and how to choose, locate, and wire an electrical receptacle in a home. Electrical receptacles (also called electrical outlets or "plugs" or "sockets") are simple devices that are easy to install, but there are details to get r

ight if you want to be safe.

Q&A on Spacing, Location & Height for Electrical Receptacles (Outlets)

These questions & answers on electrical outlet (receptacle height) were posted originally

at ELECTRICAL RECEPTACLE HEIGHT & CLEARANCES - be sure to review the outlet height specifications given in detail there.

On 2018-11-06 by (mod) - maximum height of the socket outlet from the ground

Timon

In the ELECTRICAL RECEPTACLE HEIGHTarticle where we discuss your question use the Ctrl-F function in your browser and search for "Maximum" and you will find fourteen height specifications - as there is not one "right answer".

On 2018-11-06 by Timon.M

the maximum height of the socket outlet from the ground

On 2018-10-13 by (mod) - allowing rehabbed 1930 - 1940 construction outlets both on the floor and in baseboards.

Help me help you by pointing to the US NEC code section that prohibits floor or baseboard receptacles - I haven't found that, though special materials are needed for floor receptacles.

On 2018-10-12 by Real Estate Broker

Local inspectors are allowing rehabbed 1930 - 1940 construction outlets both on the floor and in baseboards. Has the National Code changed or is our city not in compliance ?

On 2018-09-07 by (mod) - US Electrical Code Article 201.21 (B) permits the use of a 15A receptacle on a 20A circuit PROVIDED ...

Thank you for your comments Lighthouse. In our commitment to accuracy and reliability, we can use all editing and critique we can get.

You are correct that the US Electrical Code Article 201.21 (B) permits the use of a 15A receptacle on a 20A circuit PROVIDED that the maximum load to be connected to the receptacle by a cord-and-plug-connected device is 12A or less.

If the building occupant might connect to the receptacle a device that produces a load of up to 16 Amps, then the receptacle on the 20A circuit must be rated for 20A.

You are right that it is merely my OPINION that it would be good practice to install 20A-rated receptacles on a 20A circuit.

My opinion is based on my reasoning and experience in nearly 50 years of building inspection, troubleshooting, failure investigations, and first-hand wiring.

A normal building occupant who purchases and connects cord-and-plug-connected devices has not the slightest awareness of nor pays any attention to the ampere load that the device is going to produce on the circuit.

Rather, a standard consumer assumption is that "if the plug fits the socket it's ok to plug it in".

Example:

a 120V 1440-Watt King electric heater using a cord-and-plug connector will draw 12A and can be connected through a 15A-rated receptacle to a 15-A 120V circuit
while
a 120V 1920-Watt King electric heater using a cord-and-plug connector will draw 16A and must be connected through a 20A receptacle onto a 20A electrical circuit

King provides an electric heater selection guide that explains those restrictions.

However it is very common for a consumer to buy a heater whose cord-and-plug connector simply fits their circuit, take it home and plug it in without giving a thought to making the ampacity distinction given by the US NEC and by the heater manufacturer.

It is indeed just my OPINION that the best design for building features and safety is one that anticipates what people DO, not what people SHOULD DO.

Over the life of most buildings it is absolutely impossible to predict or assure that the explicit limitations given in the US NEC by Table 210.21 (B)(2) cited below are going to be known-by and respected by building occupants.

Here are the code citations:

In the U.S. the NEC - National Electrical Code, sets guidelines for installation of electrical receptacles on branch circuits. It's helpful when offering statements about what is or is not permitted in electrical codes to cite specifics.

Article 210.21 Outlet Devices. Outlet devices shall have an ampere rating that is not less than the load to be served and shall comply with 210.21(A) and (B).

I read this to mean that presuming we are talking about a 20-A electrical circuit (wired with #12 copper wire) in a building, if an occupant might connect to that circuit a device or appliance that can in fact draw 20-Amps, then the outlet device (receptacle) should also be rated for 20A.

Using the US 2008 NEC for example, we also have the following:

NEC 210.21 (B) Receptacles.

(1) Single Receptacle on an Individual Branch Circuit.

A single receptacle installed on an individual branch circuit shall have an ampere rating of not less than that of the branch circuit.

Exception No. 1: A receptacle installed in accordance with 430.81(B)/

Exception No. 2: A receptacle installed exclusively for the use of a cord-and-plug-connected arc welder shall be permitted to have an ampere rating of not less than the minimum branch-circuit conductor ampacity determined by 630.11(A) for arc welders.

NEC 210.21 (B) Receptacles. (continued)

(2) Total Cord-and-Plug-Connected Load.

Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cord-and-plug-connected load in excess of the maximum specified in Table 210.21(B)(2).

That table specifies the following:

Circuit Rating (Amperes) 15 or 20, Receptacle Rating (Amperes) 15, Maximum Load (Amperes) 12

Circuit Rating (Amperes) 20, Receptacle Rating (Amperes) 20, Maximum Load (Amperes) 16

Circuit Rating (Amperes) 30, Receptacle Rating (Amperes) 30, Maximum Load (Amperes) 24

At InspectApedia.com see BUILDING CODE DOWNLOADS https://inspectapedia.com/Design/COPIES-of-BUILDING-CODES.php#Electrical to download copies of various electrical codes and standards

At King's website this page https://www.king-electric.com/pdfs/helpful-hints-sizing-chart.pdf provides the heater sizing advice I cited.

I appreciate that you took time to write about this and I will edit the article above on this page to distinguish between OPINION and CODE.

On 2018-09-07 by (mod) - The use of multiple 15 amp receptacles on a 20 amp circuit is permitted.

The National Electrical Code, in article 210.21 (B) 1, 2, and 3, includes this remark: The use of multiple 15 amp receptacles on a 20 amp circuit is permitted.

On 2018-09-07 by Lighthouse Energy - 13 receptacles on a 20-amp (#12 copper) wire circuit."

Also I see this reply:

"10 electrical receptacles to be wired on a 15-Amp (#14 copper) wire circuit, and the Electrical Code [NEC] allows

13 receptacles on a 20-amp (#12 copper) wire circuit."

Well this is a miss again, if wiring a home, the max outlets that can be on a 15A or 20A circuit is 10, the MAX load to a circuit is 80% on a 20A home outlet circuit. 100% @ 2400W -20% = 1920W / by 185W = 10.37, round down is required here, so the answer is 10 outlets. now in a commercial installation, you need to look up the buildings occupancy classification to answer that question.

On 2018-09-07 by Lighthouse Energy

I see the comment reply to a question:

"Watch out: When purchasing the receptacles to use on a 20A circuit, be sure to also buy receptacles that are themselves rated for 20Amp use."

This reply is wrong in part. If your installing outlets on a 20A circuit, you can use 15A rated outlets. only if you are installing one outlet are you required to install a 20A outlet. if you are installing more then one outlet on a 20A circuit you can use 15A rated outlets.

On 2018-02-19 by (mod) - required spacing (in terms of maximum feet between outlets) of electrical wall outlets in a retail store space?

By NEC code since 1956 spacing needs to be as given in the article above.no place more than 6 ft from an outlet.

However depending on the particular nature of the commercial space their requirements may be different than that.

You may need receptacles at closer spacing, for example for feet, and you may need multiple circuits along the wall depending on what needs to be powered.

On 2018-02-18 by Bob Gross

What is the required spacing (in terms of maximum feet between outlets) of electrical wall outlets in a retail store space?

On 2017-09-30 by (mod) - move an electrical receptacle to where it is needed

Your electrician can indeed move an electrical receptacle to where it is needed, provided the fire clearances required by your furnace are respected. Those will be described in the installation manual for your new furnace.

On 2017-09-30 by Amy P

We are installing a new gas furnace as back up to a new heat pump. We had a gas furnace previously. The small utility room where the furnace is located has electrical conduit coming in from the ceiling and the only outlet in the small room is located 60 inches above the finished floor.

The room also used to house an electric hot water tank which has since been removed and replaced with an externally located on-demand gas hot water unit.

We'd like to relocated the outlet to a lower location but are wondering if code requires this high placement in a utility room/closet or in close proximity to a gas furnace. Thanks.

On 2017-09-01 by (mod) -

Sharon,

To have space I repeat your question and give a detailed reply in the article above. You may need to clear your browser cache and it can take some time for the updated page to appear on your server to see the new article addition, so I include a summary remark here:

Typically in an insulated wall we want to see the electrical receptacle boxes offset from one another by a distance equal to no less than the depth of the wall cavity.

Example: in a 2x4 framed stud wall the boxes would be offset from one another horizontally (assuming they're along the same horizontal line) by no less than 3 1/2" (that's the actual depth of a 2x4).

On 2017-09-01 by Sharon

In new construction, can there be an indoor (into kitchen) and outdoor outlet (on back porch) in the same bay?

On 2017-08-29 by Mike Curry

You state NEC requirements or suggestions of 10 receptacles for 15 amp. wiring and 13 receptacles for 20 amp. wiring. That is the code for commercial installations, NOT for residential installations. Basically there is no limit as to number of receptacles in residential wiring. Common sense should prevail, but the NEC has no such restrictions.

On 2017-06-07 by Anonymous

what should be the minimum distance of passing the wire above the window in wooden frame?

On 2017-04-25 by (mod) - How many outlets are required above counter height on a kitchen wall (back splash) with a sink?

Kami

Let's use the California state electrical code as a model (since we don't know your country, city, province or state)

The answer will depend on the kitchen size or total horizontal wall lengths involved.

Typically we want to see two separate 20A appliance circuits, with GFCI protection, but the actual number of receptacles can vary. No place along the wall should be more than 24" ft. from a receptacle.

Details, based on CA's adoption of the 2010 National Electrical Code in the U.S.

1) At least two 20-ampere branch circuits shall supply kitchen countertop receptacles.

2) Wall Counter Spaces

a) A receptacle shall be installed for any counter that is 12 inches wide or greater; and,

b) No point on the kitchen counter, measured at the wall may be more that 24 inches away from a receptacle. Also known as the 2ft. / 4ft. rule

3) Island and Peninsular Counter Spaces

a) At least one receptacle is required for an island or peninsular counter with dimensions of at least 24 inches by 12 inches;

b) An island counter with a rangetop or sink installed where the dimension behind the rangetop or sink to the edge of the counter is less than 12 inches is considered as two separate island countertops; and,

c) A peninsular countertop is measured from the connecting edge.

4) Receptacle installation

a) Maximum of 20 inches above countertop;

b) Maximum of 12 below island or peninsular countertops;

c) Island or peninsular countertops may not extend more than 6 inches beyond the cabinet housing the receptacle; and,

d) Receptacle may not be installed face-up in the countertop.

5) Ground-Fault Circuit-Interrupter (GFCI) protection is required for all receptacles serving kitchen countertops, as well as pantries, breakfast rooms, dining rooms and similar areas.

6) Countertops separated by sinks, ranges, or refrigerators shall be treated as separate spaces. The wall behind the sink or cook top is not to be treated as wall space unless the distance exceeds 12 inches to the wall or 18 inches to a corner

On 2017-04-25 by Kami

How many outlets are required above counter height on a kitchen wall (back splash) with a sink?

On 2017-03-05 by (mod) re: leaving the un-used punch-outs in an electrical box in place

Jim

Normally we leave the punch-outs in place except where they must be removed to install a cable connector clamp. Leaving holes in an electrical box may in fact violate local electrical and fire codes.

On 2017-03-05 by Jim

Do the punch outs on the back of the outlet boxes have to be broken off completely or do they stay in to pass code

On 2017-01-29 by Randy

HI: I'm installing an outside outlet to supply power to a fountain. The wire will be run in conduit 18" below the surface, at the vertical point, a second pipe will be run to support the waterproof box, both set in concrete.

Is the 6 1/2" minimum clearance above grade level for a box installed on the side of the house the same minimum height for the outlet on a free standing outlet?
Thanks

On 2017-01-27 by Tanner

Is there a measurement requirement for receptacles when furing out basement concrete walls. Is the minimum 4" from concrete?

On 2016-11-30 by (mod) re: overcurrent protection for service entry wiring

Chris I don't understand your situation,
But in general, you'd want a breaker to protect the wire between pole mounted meter and building.

On 2016-11-29 by chris

Do I need a shut off switch at the pole with the meter. can I use treated plywood for backing on meter.

On 2016-11-26 by Mark

As per your conversation about ground prong up or down. I prefer to have the ground prong up for the simple reason, if the plug works its way out it is not hanging by just the ground prong but rather the two "active" lines.

How many extension cords have you seen with the ground prong broken off. Ever since I went to ground up, my cords don't seem to lose their ground prongs. Go figure.

On 2016-10-19 by David

Height of indoor receptacle

On 2016-10-10 by alfred

What is the minimum distance between GFI outlet from a kitchen sink.

On 2016-09-18 by (mod)

Dennis,

Please see ELECTRIC BASEBOARD HEAT INSTALL at https://inspectapedia.com/heat/Electric_Baseboard_Heat_Installation.php where we repeat your question and give a detailed answer (at the article bottom) as part of our discussion of clearances from electrical receptacles

On 2016-09-18 by Dennis

I am installing electric hydrostatic baseboard heaters, which they do not get hot enough to damage or burn anything. how far offset must the outlets be from the side of the heater? im on a limited budget, and the last thing I need is to fail inspection.

On 2016-08-26 by Doris - electrical outlets be installed below the bathroom mirror.

Can electrical outlets be installed below the bathroom mirror.

On 2016-06-29 by Jamey

Thank you. I'll go with a weather proof box.

On 2016-06-28 by (mod) re: reqirement to protect electrical wiring and devices from water from a shower

Jamey, see some basics at

in the U.S. 1997 NEC Section 18 "Switchgear and Metal-Enclosed Bus" we find the following (excerpting)\

180. Switchgear Assemblies

A. General Requirements for All Switchgear

3. Piping containing liquids, or corrosive or hazardous gases, shall not be routed in the vicinity of switchgear unless suitable barriers are installed to protect the switchgear from damage in the event of a pipe failure.

If you have concern that your installation trips over advice such as the above, you could install weatherproof electrical boxes to contain all of the nearby wiring; that would add protection should a plumbing leak occur nearby.

ELECTRICAL RECEPTCALE WIRE CLEARANCE DISTANCES is your reference.

But I note there are no notes about wired distances to plumbing; Plumbing is discussed under different topics such as rules about grounding ("Water systems with non-metallic non-current-carrying pipe or insulating joints are not suitable for use as grounding electrodes")

2008 NFPA 70 110.26 does not explicitly address your question about electrical wire distance to plumbing pipes

F Dedicated Equipment Space. All switchboards, panelboards, distribution boards, and motor control centers shall be located in dedicated spaces and protected from damage.

Exception: Control equipment that by its very nature or because of other rules of the Code must be adjacent to or within sight of its operating machinery shall be permitted in those locations.

1 Indoor. Indoor installations shall comply with 110.26(F)(1)(a) through (F)(1)(d).

(a)Dedicated Electrical Space.

The space equal to the width and depth of the equipment and extending from the floor to a height of 1.8 m (6 ft) above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation. No piping, ducts, leak protection apparatus, or other equipment foreign to the electrical installation shall be located in this zone.

Exception: Suspended ceilings with removable panels shall be permitted within the 1.8-m (6-ft) zone.

(b)Foreign Systems.

The area above the dedicated space required by 110.26(F)(1)(a) shall be permitted to contain foreign systems, provided protection is installed to avoid damage to the electrical equipment from condensation, leaks, or breaks in such foreign systems.

(c)Sprinkler Protection.

Sprinkler protection shall be permitted for the dedicated space where the piping complies with this section.

(d)Suspended Ceilings.

A dropped, suspended, or similar ceiling that does not add strength to the building structure shall not be considered a structural ceiling.

On 2016-06-27 by Jamey

We are renovating a shower adding a new shower head in addition to the existing hand held. The stud/framing to install the drop ear elbow for the new shower arm is two feet above the inside of an electric switch box.

The switch is on the outside wall of the shower that services the light/fan inside the shower. That wall with the electric and plumbing is only 26 inches wide with the mixer valve, the new diverter and new copper tubing up to the shower ell. Is this a bad idea, not code, or is it okay.

If there's a leak at the shower arm joints the water could get into the switch box. That doesn't sound like a good idea to me. Any suggestions would be appreciated. I'm very limited on the location of the new shower head since there are 2 outside walls and this 26 inch wall.

Originally, the mixer valve was installed 6 inches away from and about the same height as the inside of the switch box in that wall. How should this be configured?

On 2016-04-28 by Anonymous

Ground outlet hole ontop or on bottom? Is it a Minnesota code to have it one way or another?

On 2015-11-23 by (mod)

Thank you anon.

It's long been the case that two views of the 12' o.c. spacing for receptacles can also be stated as equal to "nowhere are we more than 6 ft. from an electrical receptacle" since that's what 12' o.c. also provides.

On 2015-11-19 by Anonymous

you have errors in here, the code spacing for residential is 12' o.c., not more than 6' from the end of a door/opening/fireplace/etc

On 2015-11-18 1 y (mod)

Thanks for the comment, Shane.

I have not found a Canadian electrical code with the provision you name, so I would be very grateful for an actual code citation reference.

On 2015-11-18 by Shane

In canada there is a code that states receptacles must be with ground up if covered with a medal cover as in a garage. This rule use to apply to all receptacles. It is often(never not passed) missed during inspections. It appears more pleasing to the eye with ground down.

On 2015-09-2 by Daniel

Yes but it has to meet all electrical code specs on GFCI, clearance distances, etc.

On 2015-09-25 by Doug

Can I install an electrical outlet on a bathroom mirror frame?

On 2015-09-16 by Chris

I'm adding a kitchen island to our room and need to cut into our slab to bring wires to it.

What type of wires should be sent to the two outlets and what type of conduits should I run the wires through.
PVC or metal. Is THWN or THNN the preferred wires? Can I tie those into the 12-2 or 14-2 wires to the other outlets?
Thanks,
chris

On 2015-08-10 by (mod) - national electrical code does not specify electrical receptacle heights

Thank you for the question, Jay.

Generally the national electrical code does not specify electrical receptacle heights though you will find some recommendations for a minimum height above the interior floor for receptacles and switches in the Americans with Disabilities Act (ADA).

Mike Holt's forum, a resource we often consult on electrical questions, and Redwood Kardon / Doug Hansen over at Code Check, another resource, repeatedly state that there is no NEC-given minimum height. Mike adds that "common sense would place the device above the high water mark"

There are maximum heights (with possible exceptions for special-use receptacles such as for roof edge ice dam heat tapes), tyically 6ft 6 in. Max.

At a very minimum, no outdoor receptacle cover or junction box should be in ground contact if the specific box, cover, and components are not rated for wet or buried applications. But that's a bit of a cop-out I realize.

The devices must be GFCI protected.

On 2015-08-10 by Jay

I looked at the page - https://inspectapedia.com/electric/Electrical_Outlet_Height.php
Great info but what about for the exterior (outside a house)?

What is the minimum distance from the bottom to the ground for an exterior outlet?

More specifically for my case, the minimum from the bottom of a junction box (closed with waterproof gasket) to the ground. Thank you in advance, Jay - Miami, FL

On 2015-08-02 by (mod)

Thanks for the suggestion, John, I've included it along with a detailed reply in the article above.

On 2015-08-01 by John

Our electricians at work told me that they prefer to install the outlets with the ground conductor up because it reduces the chances of a metal object (i.e. paperclip) falling off of a desk and landing between the neutral and phase conductor.

With the ground conductor up, there is a better chance of such an object getting deflected or falling between the neutral and ground, which would be safer than falling between the neutral and phase conductor.

Although there is still a chance that an object might fall between ground and phase, it would be less likely than if the ground conductor was down. Because a typical 3-conductor plug is triangle in shape, an object is more likely to be deflected falling on the ground side than the phase / neutral side.

Question: what is the minimum height that indoor house wiring must be above the ground or floor level?

When running wire for a basement, is there a min height the wires must be off the ground? Not the outlet box, but the wire running through the joists. Justin Sheppard

Reply:

No, Justin. But if there is the slightest danger that wires will be nicked by someone driving a nail into a stud though which the wires are run be sure to use steel plates to protect the wire where it passes through the studs. Simple nail plates are available at any building supplier.

Question: how do I install multiple electrical outlets (receptacles) along a wall?

putting in more than outlet on along a 12ft wall - Mike Tucker

Reply:

Mike, if your comment is a question of how to put in more than one outlet along a 12 foot wall, yes it's perfectly permitted to exceed the minimum number of receptacles along a wall.

The wiring system is unchanged except that in some cases I recommend installing two different circuits and alternating which outlet is served by which circuit. That avoids overloading one circuit if you are plugging in lots of devices in one area.

Question: electrical outlet height requirements

I was looking at some height requirements on electrical outlets this is a very informational site.

thanks Jerm 4/19/12

Reply:

Jerm, in the article ELECTRICAL RECEPTACLE HEIGHT & CLEARANCES we give the data you want. Let me know if anything is unclear.

 

Question: armor around wire through concrete?

I am running a new 15A outlet into the back of a bookcase in a 50 year old house with updated electrical. The wire runs out the back of the retrofit box and down through the concrete foundation into the crawlspace to a wire I plan to splice into. Do I need to put armor around the wire run through the foundation? It goes through open air for about 2 feet and there is no way to secure it to anything.

Thanks!
Tom - 7/19/12

Reply:

You need to look at the type and rating of the electrical wire to determine if it is permitted to bury it in concrete or not.

...

Continue reading  at ELECTRICAL RECEPTACLE HEIGHT & CLEARANCES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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