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.

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6
votes
9answers
24k views

How do I put a fluorescent light on a motion sensor?

I have a couple closets in my basement that I have outfitted with a fluorescent light attached to a motion sensor (this one). The idea was that when you open the closet door, the light comes on ...
13
votes
6answers
79k views

Can I backfeed a portable generator into my house's electrical system?

Is there a safe way to power my house using a portable generator? The power rating for the generator is 6kW, and I want to run my electric water heater (4.5kW) and my refrigerator (0.5kW) and possibly ...
9
votes
1answer
22k views

How can I determine circuit breaker requirements for an electric range?

I recently had a new range installed and when an electrician was visiting, he pointed out that the circuit was over capacity because the range was rated at 12.2KW at 240V. He said 12,200 W / 240 V = ...
9
votes
3answers
3k views

There's a difference between hot/neutral AC lines in a plug, but does it matter?

Saw the good answer to this question: Is there a difference between the two conductors in 120VAC wiring? But I'm wondering as a followup, since the two primary prongs in an AC mains plug are ...
7
votes
2answers
10k views

Is it unsafe if some three prong outlets don't properly test as grounded?

It's me again -- the pest ;-) On the general inspection report for the house we're looking at buying, there's a note about the house's electrical: Some three prong outlets did not test properly ...
6
votes
1answer
788 views

What do I need to replace 4 light switches on the same circuit?

So we have a single light in our living room that can be turned on/off from four different switches at various entrances to the living room. We're currently replacing all the switches in our house as ...
5
votes
2answers
3k views

How do I wire my wall-mounted HD TV?

This image wall-mount setup should give a good idea of the current TV set up on the wall. I wanted to use a SmartStrip to power my TV and all the other devices (receiver, BluRay player, Wii, cable ...
4
votes
1answer
1k views

How do I test circuit breakers?

Suppose I need new circuit breakers and buy some at a local shop. How do I test them to be sure they haven't been damaged on their way from factory and will do their job when time comes?
1
vote
1answer
2k views

Why isn't this 3-way wiring working?

Below is a diagram that I drew to help me rewire a couple of switches. The left switch is a standard 3-way switch. The right switch Cooper 275W-BOX combination single pole and 3-way switch. The single ...
8
votes
3answers
6k views

How do I install an electrical outlet on a live circuit?

In my dorm room closet, there is a junction box with a blank plate (no outlet). Inside there are three wirenuts (hot, neutral, ground). I know it is generally unsafe to do any work on a live ...
5
votes
2answers
30k 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 ...
4
votes
2answers
5k views

What does a surge protector do that a breaker doesn't?

The circuit breakers in my home are 120VAC, 15A or 20A breakers. What would a surge protector (e.g. this or a power strip with surge protection) do that a breaker wouldn't do already?
4
votes
4answers
6k views

Should I use a GFCI or AFCI circuit breaker with knob and tube wiring?

My American house was built in 1942, and much of the wiring is still knob-and-tube wiring (2-wire, no ground). Over the years new modern wiring has been added to the house, but we still have some KnT ...
4
votes
1answer
6k views

Can I control a bathroom extractor fan independently from the light?

My bathroom extractor timer fan works fine except that I have to have the lights on when it is in use. I have 2 windows in the bathroom and feel it is a waste of energy to have the lights on in order ...
3
votes
1answer
939 views

When replacing non-grounding type receptacles is a GFCI receptacle required, or can any GFCI device be used?

Under the NEC (it was 210(7)(d)(3), but appears to have moved around some), it is permissible to replace an ungrounded receptacle with a GFCI receptacle, then wire further ungrounded or non-grounded ...
2
votes
1answer
1k views

What could cause two of my receptacles to stop working?

Problem: No power in two receptacles. Note: Both receptacles on same circuit. What I have done: Checked the 15 amps circuit breakers with a volt tester. Each breaker reads 125 volts. Bought a ...
2
votes
2answers
4k views

Can you terminate more than one common on the furnace C terminal?

TL;DR: Can you terminate more than one common on the furnace C terminal? Background: I've linked a diagram of how my non-programmable thermostat is currently hooked up. I want to replace it with a ...
1
vote
2answers
146 views

Testing and proper breakers for a multi wire branch circuit?

How do you determine if an outlet is part of a unidentified multi-wire branch circuit? Also, does code say MWBCs need to be on double throw circuit breakers and is it permissible to link CBs with that ...
1
vote
3answers
3k views

How do I determine the fill rating of a conduit?

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 ...
9
votes
8answers
53k views

How can I run Cat5e cable through a completely finished house?

My family and I are interested in buying a house that was built in 2002. This house is two floors on a concrete slab with a finished bonus room upstairs so there is no attic other than above the ...
25
votes
3answers
2k views

If DC adapters are so prevalent, why is AC used in construction by default?

I'm not sure if there's a better place to ask this or not. Why, at least here in America, is the standard electrical system set up for alternating current (AC) rather than direct current (DC)? I'm ...
15
votes
4answers
108k views

What is a GFI outlet used for, and where should I install them?

What purpose does a GFI serve? Where should they be used?
16
votes
7answers
2k views

How do I safely replace a worn out electrical outlet?

I have a number of outlets that are old and worn out (plugs fall out of them mainly.) Obviously I need to turn off the breaker to replace them safely but any guidance on how to rewire them, how to ...
11
votes
15answers
58k views

When wiring outlets should I use pigtails or both sets of outlet screws?

I'm replacing the outlets in our house and pulled out one that had two black and two white cables. My first thought was that it was two circuits, one of them being switched, but then realized the tab ...
10
votes
1answer
71k views

Why is my air conditioner tripping the circuit breaker?

Our air conditioner recently stopped blowing out cold air. When I went to check on it, I noticed that the outside unit wasn't coming on. We had had problems with ants in the contacter in the past, ...
7
votes
2answers
11k 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 ...
5
votes
4answers
8k views

How to add indicator on a light switch to indicate the outdoor 3-way light is on?

Have some carriage lights outside my garage that can be turned on from inside the house. It's common that the switch will get flipped and the lights will stay on when they're not wanted. Is there ...
4
votes
3answers
152 views

What features should I look for in a full-house surge protector?

How does one select a surge protector for a typical home? We get surges and slight drops in line voltage. We are the last pole on a small town electric provider, three miles from town. Surge ...
25
votes
7answers
36k views

Would you ever wire white and ground together?

I was replacing some outlets in my house with tamper-resistant ones, and came across one where the white and ground were wired together, as seen in this picture. Why? Is that okay or appropriate ...
14
votes
3answers
24k views

Are both legs of a home's power supply equally used?

This is basically just to satisfy my curiosity. Please correct me if I'm wrong about any of this: I believe power supply to a home's main panel usually consists of: A neutral wire A hot wire 120 ...
8
votes
2answers
2k views

How can I ground old 2-prong receptacles? (120V)

I have several old receptacles that are 2-prong. There is armored cable running from the breaker panel to each receptacle. What do I need to do in order to install and properly ground new 3-prong ...
7
votes
5answers
1k views

Is it possible to convert a switched light into an unswitched outlet?

I am installing an overhead automatic garage door opener. My only power source close to where I will be hanging the motor is an overhead light socket that is operated by a switch on the wall next to ...
7
votes
5answers
25k views

What types of electrical outlets are found in a typical home in the USA?

I do not live in the USA. If I were to buy a home in the USA, what are the key facts I should know about USA household electrical supply at outlets in homes? E.g. when buying a clothes dryer or other ...
6
votes
1answer
17k views

How should I wire a GFCI outlet and a switch to isolate the switch but provide GFCI protection further in the series?

I am replacing the outlets for my garbage disposal/dishwasher circuit in my kitchen. Currently on that breaker there is one non-GFCI outlet with a pigtailed switch controlling the garbage disposal and ...
6
votes
6answers
17k 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, ...
5
votes
1answer
13k views

Replace two-wire thermostat

I'm replacing an old mercury thermostat with a digital one. The new unit has 7-8 connections (labeled w1,wh,r1,rh,y,c, etc.) and a bunch of instructions about how to connect similarly labeled ...
4
votes
1answer
4k views

How do I install electrical through existing stucco (e.g. “old work”)

Is there such a thing as an "old work" stucco junction box? Rather than cutting and flashing a 4" hole for a new junction box, can I cut a 1/2 hole for the non-metallic cable, and attach some sort of ...
11
votes
5answers
39k views

Should I put a dimmer switch on a ceiling fan?

I have a ceiling fan on our bedroom's vaulted ceiling. Since we don't want 7' pull-cords, the speed is stuck at full-tilt, which is no good. The fan has separate switches on the wall for lights and ...
8
votes
1answer
4k views

How can I trace cable through floors and walls?

How can I work out where an electrical cable runs through walls/floors? I am building a circuit map of a 1941 house with unfinished basement. I shut off all circuits at the main service panel, switch ...
7
votes
3answers
1k views

Why am I getting strange results when using a power meter to measure CFLs?

Over the years we have replaced just about every bulb in the house with a CFL. But here is the problem. Our electric bill is going up and not down. When I moved here 3 years ago we spent about ...
7
votes
5answers
57k 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 ...
7
votes
5answers
10k views

What could be causing AFCI breaker and GFCI receptacle nuisance tripping?

I have a very unusual set of electrical issues that have proven difficult to troubleshoot. I live in a newly constructed house. Each bedroom has AFCI breakers. In the past 3 years living there, the ...
7
votes
1answer
3k views

Any reason not to ground the sheathing of MX wire?

Having recently bought an older house (c1943) I am doing a little work on the place. While rewiring a light switch I noted that there is newer Romex wiring from the distribution panel to the switch, ...
5
votes
2answers
2k views

How can I extend a wall outlet?

I have a interior brick wall, with wall outlet in it, I am covering the wall with 1/2" sheet rock. But I am ancoring 1x2's on the brick so I can hang the sheetrock. How would I extend the wall outlet ...
4
votes
5answers
11k 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 subpanel in a seperate structure if I install a seperate ground rod to the grounding bus in subpanel? I have 8/3 w/o ground ...
4
votes
4answers
25k views

Can I safely ground a light fixture if the ceiling box has two hot and one neutral wire (no ground wire)

Checking for dupes, I saw this question, but the situation appears different as my box is metal, among other things. I'm fairly new to electrical projects, so bear with me. I recently installed a new ...
4
votes
1answer
6k views

Convert line voltage heating system to use low voltage thermostats

I currently have two line voltage ceiling radiant heating systems in my condo each with their own DPST thermostat. I'd like to use low voltage thermostats such as the nest. I found this ...
4
votes
1answer
5k views

How can I diagnose disturbing voltage potentials?

Earlier today, I read Acceptable ground to neutral voltage?, and thought it'd be fun to stick my multimeter in the socket and have a voltage to report back. Neutral to ground read 60 volts. My head ...
3
votes
3answers
6k views

Hooking up a 50A hot tub breaker to a 60A subpanel

I am considering adding a hot tub to my backyard. Most of the ones I've seen require a 240v 50A breaker, presumably with #6 4-wire. It would be most convenient to run the line for this from my ...
3
votes
1answer
4k views

When wiring a switch loop, which wire is which?

If you're wiring up a lighting circuit, where the power enters at the lighting outlet. According to the National Electrical Code, which wire should be "hot" and which should be "switched hot"? ...