Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR
ACCURACY vs PRECISION of MEASUREMENTS
AFCIs ARC FAULT CIRCUIT INTERRUPTERS
ALUMINUM SECs & WIRING
ALUMINUM WIRING HAZARDS & REPAIRS
AMPS & VOLTS DETERMINATION
AMPACITY - the LIMITING FACTOR
APPLIANCE EFFICIENCY RATINGS
BACKUP ELECTRICAL GENERATORS
BACK-WIRED ELECTRICAL DEVICES
BOOKSTORE - ELECTRICAL
BUILDING SAFETY HAZARDS GUIDE
Cadet & Encore Heater Recall
CIRCUIT BREAKER FAILURE
CIRCUIT BREAKER SIZE for A/C or HEAT PUMP
Classified CIRCUIT BREAKER WARNING
CORROSION in ELECTRICAL PANELS
CORROSION & MOISTURE SOURCES in PANELS
CUTLER HAMMER PANEL FIRE
DEFINITIONS of ELECTRICAL TERMS
DIRECTORY OF ELECTRICIANS
DMM Digital Multimeter HOW TO USE
ELECTRIC METERS & METER BASES
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRIC PANEL AMPACITY
ELECTRIC PANEL INSPECTION
ELECTRIC PANEL MOISTURE
Electric Power Frequency Table
ELECTRICAL DISTRIBUTION PANELS
ELECTRICAL GROUND SYSTEM INSPECTION
ELECTRICAL SERVICE DROP
ELECTRICAL SERVICE ENTRY WIRING
EMF RF FIELD & FREQUENCY DEFINITIONS
FEDERAL PACIFIC FPE HAZARDS
FIRE SAFETY Checklist, CPSC
GFCI PROTECTION,Testing GFCIs AFCIs
HEATING COST FUEL & BTU Cost Table
HEAT TAPE USAGE GUIDE
Hertz - Definitions of KHz MHz GHz THz
KNOB & TUBE WIRING
LIGHTING, EXTERIOR GUIDE
LIGHTING, INTERIOR GUIDE
LIGHTNING PROTECTION SYSTEMS
LOW VOLTAGE BUILDING WIRING
LOW VOLTAGE TRANSFORMER TEST
MAIN DISCONNECT AMPACITY
MOISTURE SOURCES in PANELS
MURRAY SIEMENS Recall
PHOTOVOLTAIC POWER SYSTEMS
PUSHMATIC - BULLDOG PANELS
REMOTE ELECTRIC POWER, PHOTOVOLTAIC
RUST in ELECTRICAL PANELS
SAFETY for ELECTRICAL INSPECTORS
SE CABLE SIZES vs AMPS
SIEMENS MURRAY Recall
UNDERGROUND SERVICE LATERALS
VOLTS / AMPS MEASUREMENT EQUIP
VOLTAGE MEASUREMENT METHODS
WIND ENERGY SYSTEMS
WIND TURBINES & LIGHTNING
ZINSCO SYLVANIA ELECTRICAL PANELS
Types of electrical receptacles: how to select the right type of electrical receptacle (outlet): it's important to use 20-A rated receptacles if the electrical circuit is a 20-amp circuit. Don't install a grounded electrical receptacle plug on a circuit that has no electrical ground. Remember to install AFCI or GFCI devices where they are required. This article explains how to match the receptacle type to the circuit type and use. This article series describes 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 right if you want to be safe.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved.
The proper type of electrical receptacle must be selected: some receptacles are rated only for 15-Amp circuits and must not be installed on a 20-Amp circuit.
It's generally ok to plug a 15-A appliance into a 20-A circuit since that appliance is not going to overload the circuit in normal use. But the opposite is not true. If you plug a 20-Amp appliance into a 15-Amp circuit you are risking overloading the circuit and tripping the circuit breaker, blowing the fuse, or worse, overheating the circuit and risking a fire.
Below our photographs illustrate a 15-Amp grounded electrical (below left) and a 20-Amp grounded electrical receptacle (below right). You'll notice that the heavier-duty 20-Amp electrical receptacle has that T-slot at it's wider connection opening - an easy way to identify a wall receptacle rated for 20-Amps - provided that the receptacle was properly matched to the wire size and the circuit breaker or fuse size.
Details about how to wire up an electrical receptacle are at CONNECTION DETAILS - where to connect black, white, red, green, ground wires.
Older two-wire electrical circuits, such as the two circuits depicted at the right of our sketch above may provide only the hot and neutral wires and no ground wire.
If no ground wire or ground path is provided, it is improper and unsafe to install a grounding (3-prong) electrical receptacle on that circuit.
Our photo (left) shows a conventional grounded three-prong electrical receptacle - the round hole is the ground connection - at the left end of the picture closest to my thumb.
At right in the photo is an ungrounded electrical receptacle. This is the right device to install if no ground is present on the electrical circuit. You don't want to "fool" a building occupant into thinking that a ground is present when there is not one, so you don't install a receptacle that has that third ground opening in its face. Some older two-wire circuits which are covered with a flexible metal jacket ("BX" or "armored cable" wire) may provide a ground path by means of the cable jacket itself.
We don't rely on it, and in event of certain short circuits it's unsafe: the exposed metal sheathing of the wire becomes live, risking a shock.
Details about how to wire up an un-grounded receptacle are at CONNECTION for 2-WIRE RECEPTACLE CIRCUITS - no ground
The illustration at left shows the typical wiring of an electrical outlet or "receptacle", courtesy of Carson Dunlop Associates.
Click any image to see an enlarged, detailed view of electrical wiring details for "plugs" or electrical receptacles.
Ground fault protection - GFCI's: The NEC also requires that only special ground fault circuit interrupter (GFCI) protected outlets can be installed in certain hazardous locations like kitchens, baths, garages, outdoors. A GFCI-protected electrical receptacle includes circuitry that turns the electric power off at the outlet quickly should a ground-fault (electricity flowing to earth, such as through your hand and down a water pipe) be detected. 
Arc fault protection - AFCI's: Beginning in 2002 the NEC also required arc fault protection for electrical outlets for bedrooms. 
AFCI's are similar to GFCI's discussed above, but they include an additional level of protection against fire by detecting small electrical arcing at a connection - a condition that can lead to overheating and fire.
As you can see from this US CPSC photo, you can add Arc fault protection to a home circuit by installing a special circuit breaker in the electrical panel.
By this means you can provide arc fault protection and thus improved fire safety for all electrical outlets on the circuit - for example in the building's bedrooms
In the FAQs (below) we discuss the importance of wiring the Line and Load terminals of GFCIs and AFCIs correctly.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
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
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 get rid of a four-way switch
Wanting to get rid of a four way switch not sure what wires to remove in order to remove the switch. I have three switches to control one light in my kitchen is this what they call a four way switch? Any help would be very helpful - Jim
Jim, once you've got more than one electrical switch installed to control a single device - such as a kitchen light - all of the switches and wiring can be installed using three-way switches. The wiring details are right on the package.
Question: When wiring an electrical receptacle, what do I do with the red wire? Can I ground it?
I have a 3 wire (Black, White, Red and ground) feeding a outlet and I want to add another receptacle to run further down the line. The line out is 14/2. What do I do with the Hot Red wire? Can i attach it to the ground. - Rick
After capping off the red wire, can I extend the line to the next plug by following the diagram above and adding the black and white wires to the respective second screw connections?
You see, the wiring has already been installed by the builders and they left the boxes without receptacles so all I have to do is connect them to the. I don't know why the extra red wire is there. It was done over a year ago. I want to finish the connections. It runs 14/3 and then 14/2. That's why I have the extra red.
Reply: how three-wire circuits or multiwire branch circuits with a common neutral (and ground) are used and wired
Rick often electricians run a 3-wire system into a building area using two hot wires and a shared neutral, to permit providing two circuits in an area while having to pull just one wire to the area. But to sort out how your wires were connected and are being used requires some expertise, visual inspection, and testing using a VOM.
Take a look at multi-wire branch circuit wiring information and hook-up details at MULTI-WIRE CIRCUITS.
Question: how do I install multiple electrical outlets (receptacles) along a wall?
putting in more than outlet on along a 12ft wall - Mike Tucker
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: what's the difference between "line" and "load" terminal screws on electrical receptacles? How do I hook up a quad of four receptacles to an existing circuit?
Reply: how to wire line and load terminals on receptacles (outlets)
Anon: the line and load electrical wire connections are important to get right on certain electrical devices such as GFCIs and AFCIs. Our photograph (left) illustrates the line and load markings on the back of a GFCI electrical receptacle.
Looking at the side or back of the molded case of this and other electrical devices such as AFCIs, you will see that one pair of terminals will be marked "line" and the other "load".
Which wires connect to the "Line" terminals:
The Line terminals (green arrows in photo at left) on an electrical receptacle are for the incoming hot wire - the terminal marked LINE is connected to the incoming power source or the "hot" wire (typically black or red in insulation color) that connects to the brass colored screw (marked "Black" or "Noir) at the lower left " in our photo.
And the incoming neutral (white) wire from the electrical panel connects to the "Line" and "White" or "Blanc" terminal marked at the lower right in our photo
Which wires connect to the "Load" terminals"
The Load terminals (red arrows near the top of our photo at left) on an electrical receptacle are for the outgoing wires. These wires feed electrical receptacles that are located "downstream"(farther from the electrical panel) from the device. The outgoing hot or black wire (red arrow, above left in our photo) connects to the terminal marked "Load" or "Charge" and "Black" or "Noir". The outgoing white, neutral wire, connects to the terminal marked "Load" or "Charge" and "White" or "Blanc" in our photograph.
Re-stating, terminals marked LOAD on a GFCI or AFCI are intended to be used to feed other devices (such as receptacle) that are wired "downstream" from the one being worked-on. In a string of electrical receptacles wired in series, incoming electrical power flows in to the first GFCI/AFCI receptacle and is connected to the LINE terminal. The LOAD terminals of that device are connected to hot and neutral wires that subsequently are connected to the next electrical receptacle in the series.
To hook up a quad of electrical receptacles you'll need a larger junction box. And often we wire two separate electrical circuits to the box, placing one pair of receptacles on one circuit and the other on the second circuit - that approach allows us to plug more devices into the wall at that location with less chance of overloading a single electrical circuit in the building.
Watch out: while a conventional receptacle may work with the line and load terminals reversed, a GFCI or AFCI will be unsafe if wired with that mistake, and those devices will not work properly nor test properly in all circumstances. For example, if you connect the incoming "hot" wire and neutral wire to the "load" terminals on a GFCI, and if you connect wires leading to downstream electrical receptacles to the "line" terminals (these are the incorrect connections), then pushing the test button on the GFCI will not activate that device's internal trip mechanism.
Question: Which end of electrical outlets go "up"? The ground hole should be up, down, or sideways?
Can the outlet be installed any way? For example ground hole facing up, down, or sideways? thanks, - Anon
Anon, the position of installation of an electrical outlet won't affect its operation and should not normally affect its approval by the electrical inspector.
In some areas I see the outlet installed with the ground connector always "up" as in our photo at left, though to me that's less attractive than the position shown in our electrical outlet photo at far left.
I've also seen arguments expressing the OPINION that the position of the grounding pin connector might help resist the tendency of a plug to fall out of its connection. That's nonsense. If a plug is falling out of a receptacle, one of the two objects is worn or damaged and should be replaced to assure a safe, mechanically secure connection.
Question: Is 14/3 wire ok to use to wire between the light switch and the light? What about an electrical outlet on the same circuit as the ceiling light fixture?
is it okay to use 14/3 wire for power to light to switch to receptacle?
Watch out: we do not wire fixed lighting fixtures such as ceiling lights on the same circuit as electrical receptacles ("wall plugs"). If one of the two circuits should be switched off by a circuit breaker (perhaps detecting a fault or overcurrent) we want the other circuit to remain on so that room occupants are less likely to be left in darkness.
Question: how is an electrical outlet wired to the electrical panel?
how do wire the outlet plug to the electrical panel - Anon
Anon, the electrical circuit that powers an "outlet plug" or receptacle is connected, usually through building walls, ceilings, or floors, from the first receptacle in the particular series back to a fuse or circuit breaker connection in the electrical panel. The fuse or circuit breaker, by its connecting mount in the electrical panel, receives electrical power from the income electrical service.
Question: When adding an electrical outlet in a garage, what's code: metal or plastic junction box?
I am putting outlet in garage wall that has kitchen on the other side. What is code, plastic or metal? I would think in a garage fire that a plastic box would melt and fire would go through the wall faster? - Steve Smith
Steve both plastic and metal receptacle boxes are code-approved and neither, properly installed and wired, should violate the fire-rating of the wall.
Question: can I connect a pigtail from multiple hot, neutral, or ground wires over to a receptacle
I have 2 receptacles that are both side and back wired, 3 hot and 3 neutral wires. I eliminated one receptacle (capping the 3 wires together) but want to keep the other. Is it safe to just run a pigtail from the 3 wires to the receptacle? - Greg
When wiring multiple boxes in series, how do you connect both incoming and outgoing ground wires to the back of the receptacle? With 12 ga. wire, only one wire will fit under the green screw (and not very tightly, at that - there's no washer or clamp.) - Bob M.
Yes, Greg, that's a common practice. Be sure that your junction box is big enough to contain all of the wires and twist-on connectors.
Bob, similar to Greg's question, I see two approaches to hooking up the ground wire in junction boxes and at electrical receptacles.
Question: connecting 14-3 to 14-2 wires & to the junction box
How do you connect 14-3 to 14-2 to a junction box - Moe.
Moe, twist on connectors are used to connect the incoming and outgoing hot, neutral, and ground wires, and a single pigtail length in that same twist-on connector can connect the ground to the local junction box.
Watch out: when mixing 14-3 and 14-2 wires on an electrical circuit.
If the 14-3 wires are the hot wires entering the box, and if only 14-2 is leaving the junction box, cap off the unused (typically the red) hot lead.
Do not just bond it together with the outgoing hot wire in the 14-2 group. Making that mistake would short two hot leads together, would be improper, unsafe, and a fire or shock risk.
Question: how many electrical receptacles are allowed on a 20-amp circuit? How many receptacles on a 15-amp circuit?
How many receptacles can be wired To one 20 amp circuit No. 12. Wire - John K.
Our photo (left) shows a 20-Amp electrical receptacle - you can recognize it by that horizontal opening that makes the left-hand slot look like the letter "T" on its side.
Our photo (left) illustrates an electrical receptacle intended for use on a 20-Amp circuit.
Question: how to fix loose electrical receptacles in a ceramic tile or glass mirror wall wall
Is there a way to repair electrical outlets on finished (glass and ceramic tile) walls that were not installed properly without damaging the tile? The outlets and the covers pull away from the wall when the electrical cord plug in removed?
Question: Is it safe to plug a 10-Amp A/C into an outlet that is back wired?
is it safe to plug in an ac unit that runs 10 amps , into outlet that is backed wired, i had read that you don't like this method, the outlet is on third floor and is on a 15 amp breaker - Johnny B 5/2/12
Reply: Comparing Three Types of Backwired Receptacles: 20-A Clamp Type & 15-ASpring Type & Clamp Type Backwiring Devices
Details about back-wired electrical devices (receptacles & switches) are at BACK-WIRED ELECTRICAL DEVICES.
Here we will illustrate three different types of electrical receptacles that can be wired from their back-side.
Our photo (left) illustrates a spec-grade 20-Amp, 125V rated electrical receptacle that looks as if it is "back-wired" - in fact while a wire can be wrapped around the terminal screws on this device, the screw is intended to be used to tighten a rectangular brass plate against a square metal nut (silver in color) that makes a very strong and positive connection over a good area of wire surface. This receptacle is marked on its back surface as CU Wire Only - copper only. [Click images to see enlarged details.]
Contractor-grade 15-A spring-type-connector back-wired electrical receptacles (below left) provide a single opening at each of the four terminals (two neutral wires, two hot wires) on the back of the receptacle (red arrow). The yellow arrow points to a release spring that will allow removal of the wire, but we prefer not to re-use this type of back-wired receptacle. Tightening the screw at the main wire terminal (blue arrow) has nothing to do with the spring-clamp that is securing the back-wired terminal wire.
Some newer heavy-duty 15-A back-wired electrical receptacles (above right) o not rely on a simple spring-edge to contact the electrical wire, as we illustrate in our second photo (above right). Rather, when the wire is inserted into a receiving hole on the back of the receptacle (either of the two red arrows). When the terminal screw is tightened (blue arrow) that actually snugs up a clamp that contacts a much larger surface area of the back-wired wire. That's a more secure connection mechanically. On this receptacle, instead on a single back terminal accepting a single wire, there are a pair of back terminal openings at each of the four terminal screws.
Thank you for responding, my town home was built in 1999, not sure if that is considered newer or older, lights do dim though when i use 10 amp vacuum . - Johnny B.
Backwiring electrical receptacles is a permitted installation and might be found in a 1999 home - but as we show above, there are two different approaches, the second of which is a better quality installation and is in our opinion more reliable.
Question: I don't have enough wire to lower receptacles on the wall
I recently moved into a 3 1/4 story home, and I have a basement that I am trying to finish with drywall. The room is down to the studs and the electrical receptacles are about 4' up the wall. The Romex wiring is stapled, and there isn't enough wire to lower them. It is way to much work for me to replace all of the downstairs wiring right to the breaker box, so I'm wondering if it is possible to add onto the existing wires and attach wire screws or marrets within the walls before I start adding drywall, or whether I should add some kind of junction box to contain the marreted wires in between. My building code stipulations would differ in some cases because I live in Canada, but I just want to do the job right, and I do not want to take the chance of having any fire hazards, as I also have small children. - Dave 2/10/12
Reply: if you have to move an entire string of electrical receptacles complete re-wiring is faster and cheaper than adding a splice box for every device.
Dave,. you are correct to be careful about moving outlets or any other device when the existing wires are too short. The temptation is to just splice on an extension and bury that in the wall or ceiling: an illegal, improper, unsafe as well as really aggravating approach.
The proper approach is to add a junction box at each splice - we never splice 120/240V wires without including them in a box. You can reduce the wiring work a little by using plastic boxes instead of steel - avoiding having to also connect the box to the ground wire.
The proper approach also means that you don't then bury any of these splice-boxes in the walls either. Each box has to be brought to the surface and covered.
The result is a lot of work and expense and an ugly wall with an extra junction box and blind cover all along the wall over each of the now moved or lowered electrical receptacles.
Frankly I figure that especially as you've already got the wall open to the studs, if there are more than one or two receptacles to be moved you'll probably find it is actually much less total work to re-wire the entire circuit, allowing proper lengths of wires for each box. You might carefully remove and re-route the existing wire lower in the wall or you might buy all new electrical wire - depending on the age and condition of the existing materials.
Watch out: when removing wire that appears to be in good condition, if you nick the insulation you've created a new hazard.
Question: how do I increase the projection of outlets into a room so I can add a kitchen backsplash
I am unable to find instructions on how to increase the projection into the room of existing electrical outlets so that I can tile the kitchen backsplash and have the outlets be at the appropriate depth for use and safety. Do I move forward the box to which the outlet is screwed and if so how? - Anne 3/22/12
Reply: use electrical box extenders - shop for an "electrical box extension" of the proper thickness
Building suppliers like Home Depot and also your electrical supply house sell "box extenders" in varying thicknesses, made of plastic, code approved, for the purpose you describe. The electrical box extender is sized and shaped to match the electrical receptacle box to which it is to fit. By removing the electrical receptacle from its mount on the existing box, the box extender is fit as a sort of large rectangular plastic washer, mounting between the existing box edge or surface and the mounting ears of the receptacle or switch.
Electrical box extensions are sold in plastic and steel and in thicknesses from about 1/8" up to an inch or even more. The plastic electrical "gang box extension" shown at above left is produced by Arlington Industries but there are several manufacturers. Just choose an electrical box extender that brings your receptacles far enough forward to suit the thickness of the kitchen backsplash or tile.
Watch out: don't try a makeshift substitute using washers or junk - that's an improper and unsafe repair, leaving a gap around the electrical box sides.
While I was changing a failed plug I noticed that the box was too deep. I looked into extenders, and plastic ones (Arlington BE1) are less expensive. Are CSA approved plastic box extenders code compliant for homes? - Gary 7/19/12
Question: electrical outlet height requirements
I was looking at some height requirements on electrical outlets this is a very informational site.
Jerm, in the article above at HEIGHT above FLOOR for OUTLETS we give the data you want. Let me know if anything is unclear.
Question: how do I wire a switched electrical receptacle?
I have double receptacle that has 3 wires coming in: one being the main power wire; one is incoming which feeds another receptacle, and the 3rd wire will feed a single pole switch. How do I wire the receptacle and then, how do I wire the single pole switch with 2 incoming wires? - JMS 6/3/12
JMS I don't have a perfectly clear idea of what you are wiring, but it may help to simplify: using a twist on connector and additional short wire lengths, the incoming hot and neutral can then be connected to receptacles in the same box, and any outgoing hot and neutral join the same twist on connectors.
Question: what do I do with a third white wire attached to the side of the old receptacle when I'm moving them
I have changed several receptacles in my 1994 home, but this time when removing the receptacle from the wall I see a third white wire attached to the side of the old receptacle. Can you explain to me what this third neutral wire is? - DW 6/12/12
DW, it is just too dangerous to claim to know what wiring connections someone has made in a building that is unseen and untested.
It would be common for an additional white wire connected to an electrical receptacle to be carrying the neutral line to another receptacle downstream. In other words the incoming neutral is connected to one terminal and the outgoing neutral is connected to a second screw that is electrically common with the first.
Check for a second hot wire also present in the same box.
Question: what do I do with the screws to which no wire is connected on a conventional "plug" (wall receptacle)?
At the end of a circuit, I'm only using 2 of the 4 screws on a conventional plug. What should I do with the 2 unused screws? Should they be screwed all the way in? Or left partially unscrewed? Or does it matter? - Chris Rasko 7/8/12
Question: can I add an electrical outlet on the wall where there is already a light switch?
I would like to wire in an outlet on the same wall where there is currently a light switch. Can I run wires from the light switch to power the outlet?The light switch is a 2 way switch. thank you. - Marv Walker 7/10/12
Well yes, maybe, sort-of.
Because a light switch is indeed switching a hot wire to the light, you've got power at the switch location. But depending on how the building is wired, you may not have an acceptable neutral wire, and in some still older circuits you may not have a safe ground wire.
Provided that you know how to work on electrical wiring without getting killed by electrocution, you (or your electrician) will open the switch box, carefully pull the switch assembly out enough to inspect for additional wires that may be present, and then use a VOM or DMM or even a simple neon tester to determine what wires are present.
To add a receptacle you need a proper hot, neutral and ground wire.
Watch out: if the "hot" wire in your light switch is on a 3-way circuit you may not always have power at your add-on receptacle.
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.
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.
Question: Am I allowed to add one more outlet onto an existing string?
I have an existing outlet being used for lamps I want to run one more outlet shares from the hot on is it okay? - Phantom 113 8/1/12
Question: I am trying to hook up two receptacles from a single line pair
I’m attempting to wire two separate receptacles from one (line) wire, not in-line one after the other but effectively as a “Y” from a junction box with two load lines out (one to a north wall receptacle and the other to a south wall receptacle in my barn).
Using screw-on connectors, I connected the three black wires together; the three white wires together; and the three green wires to a pigtail screwed into the junction box. One receptacle works fine, but plugging anything into the other receptacle trips the circuit breaker. If this is not the correct wiring configuration within the junction box, what is the solution? - Robert 8/9/12
Question: is it legal to convert a split receptacle into two separate receptacles
Is it legal to change a spit receptacle to two separate receptacles? - Gord
Watch out about overloading the circuit however.
Question: I've lost electrical power to the whole room after testing power at the light switch
I've lost elec to the whole room.
I tested the wiring at the light switch.
If I turn the switch off I get elec to the switch,If I turn it on I get no elec.to the switch. I've lost electricity to the whole room - Dave
Dave, your wiring or perhaps the switch itself is unsafe; sounds as if it's shorted. Leave the circuit off until the wiring has been traced, lest you start a fire or zap someone.
Question: which way is "right side up" for electrical outlets - more views
One comment regarding 'inverted' outlet mounting (ground up, vs down).
Reply: secret codes are confusing
Question: converting 2-prong to 3-prong grounded electrical receptacles on a two-wire system
I'm changing out 2 prong receptacles to two prong + ground receptacles on a two wire system. The boxes are metal. Is it acceptable to screw a bare wire to the box with a self tapping screw and hook to the ground screw? Do I need to check to make sure the box is grounded, if so, what is the best method? - Ben 10/9/12
Watch out: no, what you propose is improper and unsafe even though it would "appear" to work. To add a grounding conductor or "ground wire" to a two-wire circuit you need to add a physical wire. The dangers of using the existing metal box and BX or armored cable for the ground path (I know that it's tempting) are several:
That path, which relies on numerous parts that can often be loose, is unreliable: the path is from the new grounded receptacle's internal grounding connector through a rivet to a metal strap on the body of the receptacle, through mounting screws through the receptacle's mounting ears, through a threaded hole in the metal receptacle box, through a metal BX connector which itself relies on at least four parts to be secured to the metal box, through a set screw from that connector into the armored cable, and though god knows how many more sets of these parts down the entire remainder of the electrical circuit.
That path also is not intended to carry current, and should it do so in an emergency, someone touching the BX exterior could be electrocuted.
Finally, the receptacle manufacturer provides a ground screw on the receptacle that is intended to be connected by copper wire to a ground wire, parts and codes being ignored if you try using the box and its wire as the ground path.
On an ungrounded electrical circuit you should install only two-prong, ungrounded receptacles - that is code compliant and that also lets users know that there is no reliable electrical ground present.
Question: are receptacles wired after a GFI receptacle OK?
Are receptacles wired after GFI receptacles OK? - Denny 11/25/12
Watch out: When wiring a GFCI the incoming leads are connected to the LINE terminals and the downstream receptacles are connected to the LOAD terminals marked on the back of the receptacle. If the devices is not wired correctly it is unsafe and does not provide the intended safety protection from ground faults.
Question: how do I wire multi-way light switches so that all switches can be "down" or "up" when the lights are all off.
How should multiple way light switches be wired so that when all switches are down/up the light is off? Only some of the two-way switches in the house are working that way. With the 3-way and 4-way there's always one switch that has to be opposite the others.
Jim this is one of my favorite questions - thanks. Because a circuit with two or more "three-way" switches installed can be turned on or off from any of the switches on the circuit, it is impossible to wire the circuit so that when the circuit is "OFF" all of the switches are in a predictable position, say "down" (which we like to use to mean "off").
Imagine that all the switches are "down" and the lights are off (which is a possible case). Someone turns the lights ON at switch #1.
When someone wants to turn that light OFF, IF and ONLY IF that very same switch (now in the "up" position) is used, then by definition they are going to be using some other switch (now in the "down" position). When that "other" switch is used to turn lights off, it was "down" and is now switched "up".
You can't get there from here on a conventional 120V 3 or 4 or n-way lighting circuit.
Question: 3 plugs on one of my walls went out
Ok from everything I can tell I'm having trouble with trouble with 3 plugs on my outer wall has went out. I've did the common thing checked my breakers they are fine. Must not I have 2 switches in this room one on each wall but they do nothing I feel somehow those switches are connected to those 3 plugs. I've pulled the covers off each plug and noticed the wires are secured. I've flipped the switches in many combos with something plugged in and they still don't work at all. What can I do to fix it. I want to avoid calling a electrician if possible. - Josh DeBerry 12/11/12
Start by checking fuses or circuit breakers. If there is no tripped breaker or blown fuse, I suspect a damaged receptacle, wire, or wire connector. Your electrician will track down the location of the fault. But if you know which receptacles were all wired on a given circuit, and with power on at the electrical panel, using a receptacle tester you can check to see if any of the devices on the circuit have power.
\Since receptacles are most often wired in a daisy-chain or series circuit, the last one that has power tells you that the problem is between that receptacle and the next one in the chain.
Question: I need to add a light, fan, and fan switch to an existing bath - I can't find where to kill the power
very informative article thumbs up . I have a question though
I have one line with power coming into a box that will have one two way switch, one three way switch and one power line exiting. Is it proper to splice the incoming black wire to make 3 black wires by pig tailing with wire connectors and doing the same for the white wire and ground? - is it ok? 12/13/12
I'm sorry but I'm confused by the question. I think it's safe to say that in general it's common practice to use a twist-on connector to splice pigtails or individual wires at an individual hot or neutral wire where more connections are needed than fit with the original wire.
Just watch out to avoid violating the space or number of connectors permitted in a junction box of the particular size you're working on.
Electrical wiring are the devices that are used to generate electricity. There are different types of electrical wiring that are usually vary according to three factors - purpose, quantity of electricity to be carried, and location. All the above three factors are really very important while doing electrical wiring. - Bella Cruse, Dublin electrical contractor
Question: which circuit is better to use when adding a closet light
If I want to add light to closet, which circuit is it better to pull from? I have access to 120 plug and switches in outside wall facing away from closet that could be pulled into closet. Also, can you help explain the two different wiring configurations on my non GFI plugs. On two different plugs on different walls the plugs are 8 wire push in style (4 hot and 4 common), but the wiring configuration is different between the two plugs. One one all white and black are inserted in the bottom 4 connectors with tabs in place. On another same style plug, one set of 4 wires (2 black and 2 white) are inserted in bottom left row, and other set of 4 wires are inserted in opposite side top row. These plugs are not controlled by switches. Thank you. - Chris 12/30/12
In my OPINION, it's best to connect a closet light to the room lighting circuit if possible.
About your other question, I'm a little confused by the query, but in general, receptacles and switches often have more than one permitted connection point, such as under a screw terminal, on older devices via a back-wiring push-in connector (something we do not recommend using), or on newer devices a side-clamp operated by a screw.
In all events, regardless of which connection point you are using, receptacles and switches have a designated side or screw or connector set for the white (neutral wire) (typically the side that has a silver colored screw and that is marked NEUTRAL on the device) and for the black (hot wire) (typically the side that has a brass-colored screw and is marked LINE or HOT or BLACKI).
Question: I'm installing a box extension but the top screw won't hold - it's stripped
I started installing a box-extender on a receptacle in my kitchen because I'm tiling my backsplash and need to raise the outlet above the tile. However, the top screw connecting the outlet and box wouldn't hold. I spent way too much time bent double under my cabinets trying to get it to bite, but when I finally gave up and pulled it out it was stripped at the tip (which was as far as it'd go in). I'm sorry to bother you with triviality, but I'm new to home renovations and don't know what to do. Advice? - Julia 1/29/13
Reply: step by step tips for replacing a stripped electrical receptacle or switch box mounting screw or screw opening
If the problem is the screw itself is stripped, simply purchase a replacement screw or a hand full of them from your electrical supplier. These screws are a standard thread and length, but longer versions are available at any hardware store.
For the case you describe, if the stripped problem is the mounting hole you'll need to either enlarge and tap the hole for tine next size larger screw, or purchase a clip-on adapter that slips over the stripped ear through which the original hole passed.
Taking care to move electrical wires out of the way of your drill bit, in a metal electrical box you can drill out the 6/32 screw opening to tap and accept an 8/32 screw.
For photos and step by step details on how to repair stripped electrical outlet mounting screws, see OUTLET SCREW REPAIR.
Questions & answers or comments about how to install and wire electrical outlets or receptacles in buildings.
Ask a Question or Enter Search Terms in the InspectApedia search box just below.
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.