Questions tagged [electrical]

Distribution and use of electricity throughout the home. Electrical standards vary greatly worldwide, so you need to provide your location in your question or profile to ensure you get answers that are relevant to you. Posting photographs of wiring junctions or drawing a wiring diagram and posting it is also highly recommended.

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36 votes
2 answers
23k views

What is a tandem breaker (aka duplex, cheater, twin, double-stuff, etc.)?

I keep hearing about tandem breakers, and how they won't work with 240V loads and how they should never be used for a multi-wire branch circuit. Aside from those issues... What is a tandem breaker? ...
20 votes
3 answers
2k views

First time changing switches and outlets (receptacles). Anything special I should know?

I am replacing a bunch of switches and receptacles in my house. While I understand the basics, this is pretty much my first electrical project, and I figure there must be some hidden "gotchas" or ...
27 votes
3 answers
929k views

What wire gauge do I need for a 100 Amp subpanel at the end of a 60' wire run?

I am adding an attached garage to my house. I'm going to be putting in a 100 Amp subpanel which is about 60 feet away and run through the basement joists. What gauge wire do you recommend for ...
30 votes
6 answers
8k views

Electric shock - was I stupid, unlucky, or a combination of both?

One of the double sockets in our garage needed replacing (damaged after a washing pole hit it) - a pretty trivial job that I'd done before. So I flipped the MCB for the ring main, used a non-contact ...
  • 301
29 votes
9 answers
294k views

How do I install a GFCI receptacle with two hot wires and common neutral?

In my kitchen, I want to replace a regular 120V receptacle with a GFCI-protected receptacle. The instructions describe what to do with a regular 2-wire + ground feed, with and without daisy chaining ...
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48 votes
10 answers
68k views

Should old knob and tube wiring be replaced?

I have been doing some electrical work in my house and I noticed it has old knob and tube wiring that is still hot, should this be replaced as found or is it fine to just leave it? It seems really ...
  • 130k
31 votes
5 answers
466k views

Is it ok to have mixed grounds and neutrals on bars in a breaker box?

So to continue my line of electrical questioning (and perhaps narrow down my flickering light problem), I took a look through the two panels in this house. There is a 200amp main service in the ...
  • 5,045
30 votes
5 answers
55k views

Is it OK to borrow a ground wire from a different circuit?

I've got a circuit in the basement carrying a handful of outlets. This circuit has no ground wire. I want to add a couple of outlets and want them to be grounded. I may even want gfci outlets on ...
  • 2,330
29 votes
9 answers
133k views

Is there a way to simply splice in an additional length of 12/2 NM-B cable?

Is there a way without using junction boxes to simply splice in additional length of 12/2 NM-B cable? Can I use twist caps? I'm putting in a dog door and as it so happens, there is some 12/2 right in ...
  • 557
41 votes
12 answers
300k views

Is using 15 amp components on a 20 amp breaker against code?

I have noticed in a few different houses in Oklahoma that 20 amp breakers are used, but all of the outlets and switches only seem to be rated for 15 amps. This goes against everything I know to be ...
  • 2,020
31 votes
4 answers
150k views

Should all Federal Pacific panels be replaced?

I understand that Federal Panel Stab Lok breakers have the potential for becoming stuck, overheating, and starting fires. My home has a Federal Pacific panel but no outward markings of being a Stab ...
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59 votes
7 answers
443k views

Can Romex (NM-B) cable be run through conduit?

A few days ago I asked an electrician if I could run cable through conduit - he gave me a funny look and said "No, Romex is not allowed in conduit." When I searched online, there seems to be ...
4 votes
2 answers
96k views

Unexpected voltage with switch turned off

I am doing some work on a ceiling light and I notice that, even though the light-switch is off, my voltage tester shows voltage present. Answers to other questions (below) explain about phantom ...
13 votes
4 answers
302k views

Where does the ground wire go in a 3-prong dryer cord configuration?

We moved to a new place where the dryer connection is 3-prong instead of 4-prong. The dryer was originally 4-prong, so we bought a 3-prong cord and installed it. It works fine, except I am not ...
13 votes
2 answers
68k views

Why am I measuring 16 volts on a wire that should be at 0 volts?

I am replacing a power receptacle at my apartment. It has the standard four wires, with one of the two reds going to a nearby toggle switch. I am concerned because when the toggle switch is off, I ...
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11 votes
8 answers
181k views

Do the breaker amp readings sum up to dictate my current panels total / possible amperage?

So I know practically nothing about houses having rented for many years, just bought a house and was told by my inspector the panel is only a 70 amp panel and will need to be upgraded before I go to ...
39 votes
8 answers
490k views

Why Do 240V Circuits Not Require Neutral?

Someone told me that a 240V circuit does not require a neutral wire in the cable. Can anyone explain this phenomenon from the electricity perspective and generally explain why circuits do and do not ...
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36 votes
8 answers
10k views

How best can I discover what is up with my electrical bill?

This might be subjective, I don't know. However, it's a serious problem for me. My electrical bill is outrageous. It's three times as large as my next-door neighbor, and four or five times the size of ...
  • 503
17 votes
10 answers
268k views

Why would a GFCI trip on refrigerator circuit?

My refrigerator is tripping the GFCI on the socket into which it is plugged. Searching about this topic seems to indicate that this is a reasonably common complaint. However, I can't find any ...
  • 273
22 votes
7 answers
223k views

What is the proper 'per code' method for running nonmetallic sheathed cable above a ceiling in the attic?

Can the wiring be run over the top of the ceiling joist, or must it be run through bored holes when running perpendicular to the joists? This is a non-habitable space, will have an attic entrance ...
  • 221
13 votes
2 answers
17k views

How can I replace 2-prong receptacles in a code compliant way?

I have some 2-prong non-grounding type receptacles, and I'd like to replace them with 3-prong grounding type receptacles. According to National Electrical Code, what are my options?
  • 130k
40 votes
4 answers
320k views

How should I rewire a miswired 3-way switch?

I have a 3 way switch that was wired incorrectly when the switches were replaced with a different color switch. Is there a methodical way for me to identify which wires represent which piece of the ...
27 votes
3 answers
7k views

Now I realize I used too many GFCI outlets. How can I reclaim them?

Yeah, so the building inspector redflagged a bunch of outlets for not being GFCI. Before I understood how the LOAD terminals work, I just replaced every single one with a GFCI outlet. Most had a ...
26 votes
6 answers
135k views

Where should I NOT use a GFCI or AFCI?

There is a lot of information out there about the benefits of GFCI and AFCI and the places where they must or should be used. But are there any circumstances where you're better off without them? If I ...
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11 votes
5 answers
80k views

Can different gauges of wire be used on the same circuit?

My father-in-law is a builder. He has put in 20 amp and 15 amp breakers, and ran 12-2 as the home runs to the switch's and the first plug to make them hot. He then ran 14-2 to feed the rest of the ...
  • 121
30 votes
7 answers
100k views

Extension cord and power strip safety

I've heard that there are some safety and building code issues involved with using extension cords or power strips (surge protectors) for anything other than temporary use. What are the issues, and ...
  • 811
13 votes
1 answer
184k views

What size wire should I use to feed a subpanel in my garage?

My main panel has been upgraded to 100 amps. I would like to add a subpanel in the garage which would supply: 20 amp Mig welder running on 120 volts, but later upgrade to a larger Mig welder as i ...
  • 131
13 votes
4 answers
169k views

How to properly ground a subpanel in detached building?

I Will be installing a subpanel in a detached garage. The subpanel will be 60 amp. The garage is about 30' from the main-panel in-house, and I will of course get an exact length before selecting the ...
  • 1,074
11 votes
3 answers
9k views

Can ground shock me? It's bonded to neutral in my panel

I have no outdoor outlets. I want to install a GFCI outlet underneath my main service panel. Inside the panel there is only one bar with both ground and neutral wires connected to it. If I connect ...
  • 111
8 votes
1 answer
91k views

How do I wire a GFCI/Switch Combo?

I'm replacing an old GFCI/Switch combo. In the old one there are two wires coming into the line side, a hot wire and a neutral. On the load side there is one wire leading up to the lighting fixture. ...
20 votes
4 answers
284k views

Which Kitchen outlets do NOT need GFCI?

I have the 2 circuits in the kitchen with GFCI outlets, but I'm not quite sure which other ones do NOT need GFCI. Other circuits in the kitchen include Microwave, Fridge, and Dishwasher. It makes ...
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20 votes
7 answers
141k views

Why is it safe to use 15 A receptacles on a 20 A circuit?

OK, the one answer I got was way off target, and another commenter couldn't figure out what I was asking, so I'm restating the question... Are 15A 3-prong grounded outlets actually rated to 20A, ...
  • 14k
17 votes
1 answer
3k views

Can cable splice devices be concealed?

Devices exist that claim to be able to splice nonmetallic sheathed cables together outside of a box, and in concealed locations. Are these types of devices allowed by National Electrical Code? Here's ...
  • 130k
16 votes
3 answers
99k views

What is electrical code for number of wires in a breaker?

US, Georgia I am adding some new ciruits to add some additional outlets. The closest place is to run a wire to the main panel box. My question is, can I connect more than one wire to a breaker and ...
16 votes
2 answers
27k views

What is a multiwire branch circuit?

What is a multiwire branch circuit? (also known as "multiwire circuit", "multiwire branch circuit", "split phase shared neutral", "two circuits fed from one 12-3 or ...
  • 4,774
14 votes
4 answers
4k views

Why not use a plastic receptacle box for an outdoor outlet?

This answer says "... it should be possible to cut into the wall and install a metal box (don't use plastic, please) [for an outdoor outlet]." What are the problems associated with using a ...
  • 1,025
12 votes
2 answers
4k views

What are the pros and cons of different types of smart switches (that are on the US market) ?

When putting in a new switch for a light it is often less work to put in a smart switch than run the mains cables. However, how do you choose the type of smart switch to use? See also "What are ...
10 votes
3 answers
387k views

How should I connect the ground wire for my light fixture?

I am replacing a light fixture in my bathroom and have the following setup: The electrical box is plastic The wire coming from supply has black (hot), white (neutral) and copper (ground). The light ...
9 votes
2 answers
5k views

Can I run stripped Romex/NM through conduit?

If I have NM cable running into a junction box, can I strip the sheath of the NM cable starting inside the junction box and run the conductors without a sheath through conduit that is connected to the ...
  • 113
8 votes
3 answers
23k views

Can you run a junction inside an outlet or recessed light

I have been working on finishing my basement and am starting my rough in electrical. I am learning as I go and have gotten most of the basics down.. calc load, box size, stapling, supports etc. One ...
1 vote
2 answers
9k views

multiple motion detectors wired together

I would like to wire multiple motion detector light kits in parallel, so when one motion detector is tripped it will turn on all three lights. Each light kit has 2 LED lights on it. Schematic and ...
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51 votes
10 answers
32k views

Which way is up? (electric outlet)

My house has electric outlets in both orientations. Which one is correct? Should the ground hole be at the bottom or the top? OR
  • 1,312
45 votes
8 answers
127k views

How do I run wires for a wall-mount flatscreen TV?

Like a lot of you, we have several wall-mounted LCD HDTVs in the house. The TVs have two wires -- power and HDMI -- running down the wall to the power outlet and cable box. I've historically been too ...
  • 1,079
41 votes
7 answers
140k views

Are push in connectors up to code?

Just came across a neat product at the local hardware store, but I wonder if they are up to code and safe to use. They are a wire nut that allows you to simply push the wires in, instead of twisting ...
  • 130k
27 votes
5 answers
120k views

Do I really have to fasten interior-wall electrical wire to a stud to keep it from moving?

I am fresh out of cable staples and would rather not go all the way to Lowe's just to get a box. What are the implications of not fastening loose electrical wires to a stud? It's not like there's ...
24 votes
2 answers
126k views

How do you plan capacity for electrical circuits?

I'm finishing a section of my basement, which currently only has one bulb for bare light. In planning the electrical arrangement of things, how do I estimate the load of light fixtures or electrical ...
  • 2,078
16 votes
6 answers
235k views

Can I connect ground to neutral in a 3 wire outlet?

I have a 3 wire outlet with the entrances for hot, neutral and ground. But I know that the ground entrance is not really grounded, so in effect useless. Now, since the neutral is grounded, could I ...
15 votes
1 answer
87k views

Can I add a standard receptacle on a GFCI circuit

So, I want to add a receptacle in the bathroom (I tend to run out of batteries on my phone while crapping at the end of the day). There's a GFCI outlet on the other side of the crapper wall that ...
  • 343
12 votes
3 answers
273k views

Is a ground required when replacing an old single pole single throw switch?

I need to replace a switch that controls a single light source in a bathroom. The switch has two wires connected to it. I bought a replacement switch that has two screws (one for each wire), and a ...
  • 499
12 votes
1 answer
22k views

How exactly does a 3-way switch work?

I just finished replacing all of the switches and outlets in my apartment, after fighting a long war with a weird 3-way switch. Needless to say, I won, but I'm still trying to grasp the concept of how ...
  • 1,151

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