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Questions tagged [electrical]

Distribution and use of electricity throughout the home. Electrical standards vary greatly worldwide, so providing your location in your question or your profile helps 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.

16
votes
2answers
3k 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?
18
votes
3answers
530k 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 ...
26
votes
9answers
200k 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 ...
27
votes
5answers
30k 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 ...
37
votes
10answers
51k 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 ...
23
votes
6answers
5k 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 ...
24
votes
5answers
271k 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 ...
30
votes
12answers
180k 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 ...
24
votes
6answers
68k 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 ...
9
votes
3answers
207k 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 ...
12
votes
2answers
14k 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?
10
votes
8answers
140k 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 ...
35
votes
6answers
168k views

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

A few days ago I asked an electrician if I could run Romex 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 a wide ...
8
votes
4answers
106k 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 ...
25
votes
6answers
91k 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 ...
9
votes
1answer
139k 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 ...
7
votes
1answer
68k 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. ...
8
votes
2answers
38k 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 ...
33
votes
3answers
237k 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 ...
11
votes
2answers
3k 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 ...
8
votes
3answers
15k 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 ...
7
votes
3answers
3k 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 ...
42
votes
8answers
118k 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 ...
22
votes
2answers
116k 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 ...
31
votes
7answers
8k 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 ...
23
votes
8answers
260k 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 ...
19
votes
2answers
114k 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 ...
15
votes
6answers
167k 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 ...
14
votes
1answer
56k 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 ...
6
votes
5answers
71k views

Why am I getting 50V at a light when the switch is off?

I am trying to put in a switch and a light it controls in a storage building and this is how I wired it. Click for larger view When I checked the wiring it registered 120V when the switch was on, ...
1
vote
2answers
3k 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 ...
21
votes
4answers
74k 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 ...
19
votes
8answers
49k views

Does a homeowner need a permit for electrical work in Massachusetts?

Does a homeowner need to obtain a permit from the town in order to do electrical work on his own house in Massachusetts? The unofficial answers I can find online (e.g., this forum and the websites of ...
17
votes
4answers
120k views

I have a 3-pronged receptacle but no ground wire connected to it. Is this ok?

I removed the plates from outlets to paint walls and noticed that some of my electric boxes have ground wires connected to outlets while others do not have a green wire at all. Is this ok? I know ...
34
votes
7answers
74k 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 ...
18
votes
4answers
189k 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 ...
13
votes
5answers
109k 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 ...
12
votes
1answer
19k 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 ...
8
votes
5answers
79k views

Why would my TV image turn black when electrical appliances turn on?

I have my computer connected to my TV via HDMI. Every time something electrical happens (fridge turns on, stove sparks, etc), the image on the TV goes black for a second and then comes back on. And ...
16
votes
5answers
60k views

Where *shouldn't* I use GFCI/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 ...
9
votes
7answers
61k 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, ...
8
votes
1answer
62k views

How can I install this programmable switch where a neutral is not present?

I'm trying install this programmable switch but the instructions do not match reality. The instructions refer to the existence of a black (load) cable and a white (neutral) cable supposedly coming out ...
13
votes
1answer
1k 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 ...
9
votes
5answers
181k views

Can different gauge wiring be used in the same circuit?

I am extending a lighting and outlet circuit in a basement. The current setup has the following characteristics 15 amp. circuit breaker (200 amp service) 4 existing lighting fixtures using CFL bulbs (...
9
votes
3answers
86k views

Is it code-legal to have a circuit breaker box within a storage room?

I am currently in the process of planning a room remodel to convert an existing bedroom into a home office and storage room. One thing that makes this conversion a little bit tricky, is the existence ...
6
votes
2answers
16k views

How do I convert a light circuit with a single pole switch to use two 3-way switches?

I have a box in the hall which includes a 3-way switch (with another switch at the other end of the hall), a single pole switch to the garage lights and a single pole switch to the exterior lights on ...
5
votes
6answers
33k views

Can I install a Subpanel (in a seperate building) using a 3 wire connection (2 hots and 1 grounded neutral)?

Can I use a 3 wire connection (2 hots and 1 grounded neutral) to install a sub panel in a separate structure if I install a separate ground rod to the grounding bus in sub panel? I have 8/3 w/o ...
8
votes
2answers
44k views

Insufficient voltage to dryer receptacle; what next?

I just moved into a home and I am hooking up a used dryer (which I'm told works). The dryer spins, but I get no heat. I bought a multimeter, and it tells me that the receptacle provides insufficient ...
6
votes
4answers
6k views

Can I run a ground wire of a single circuit to the panel outside the house?

This is a follow-up to this question. I am adding (outlets) on to a 2-wire 12AWG (no ground) circuit and I want the new outlets grounded. Can I run a ground wire to the panel along the outside of ...
6
votes
6answers
38k views

Why does my GFCI circuit breaker trip with any small load, even after replacing the breaker?

I have a 20A 240V GFCI breaker in my main breaker box going to a conduit to another breaker box outside. All worked well last summer. Now, when I put any load (weed-eater, light, etc.) on an outlet ...