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13
votes
5answers
1k views

Is there a lifetime failure count for a breaker?

I have an external cutoff for my air conditioner that has two physical fuses (TR-50's, time delay 50 amps) outside. This is between the condenser unit and the main power panel, where it is protected ...
9
votes
3answers
4k 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 ...
9
votes
5answers
40k views

How do I add more circuit breakers once the breaker box is full?

My house was completely rewired by the previous owner. They tore out all the old knob-and-tube and replaced it with modern wiring. I definitely appreciate this, but unfortunately they left ...
9
votes
4answers
5k views

What is simplest strategy to map circuits to breakers in the panel?

My breaker box is very poorly labeled and I want to figure out which circuits may have overloaded (or close to it) and which could reasonably handle a little more. In the past I have just tried ...
9
votes
5answers
3k views

Why would there be a 50 amp plug on a 30 amp appliance?

I have an old conveyor dryer, which my office purchased used some time ago, just sitting in storage. The dryer is for silk screen t-shirts and has a large heating element and a variable speed conveyor ...
9
votes
4answers
5k views

Why does my microwave keep throwing the circuit breaker?

I have a circuit that powers several things in my house: Kitchen microwave Basement lights Basement sockets Sump pump Recently, this circuit has been thrown with alarming frequency when I use the ...
8
votes
4answers
659 views

How can I automatically disconnect a coffee maker and space heater without tripping the building's 20A circuit breaker?

My small office has a 20A breaker and we have to run a space heater in the winter or else we freeze to death. Whenever someone turns on the coffee maker, the office circuit breaker trips and ...
8
votes
1answer
613 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 = ...
8
votes
1answer
1k views

Is there an average number of outlets that are wired off of one circuit breaker?

I recently demolished my basement to start a reconstruction/improvement project. My first horror was the electrical layout. I've got hidden junctions, mismatched wire sizes, improper junctions and ...
7
votes
7answers
4k views

How is it that two breaker switches control the same things?

Forewarning: I don't know that much about electrical terms, so please excuse any mistakes I've possibly made. I recently moved the TV in my living room and ran a new line for the electricity to the ...
7
votes
4answers
3k views

Can I replace an outlet that uses knob and tube wiring with a grounded outlet?

Can I replace an outlet that uses knob and tube wiring with a grounded outlet? Obviously the best choice would be to replace the old wiring. Is there a standard way to ground these outlets? Do I need ...
7
votes
2answers
1k views

Are there any “easy” ways to trace a home electrical system?

We bought a home a few months ago, and the electrical panel (and subpanel) are completely unlabelled. We have no way, short of flipping breakers, to know what breaker powers which fixtures. Is there a ...
7
votes
2answers
1k views

Is it ever safe to have 14 gauge wire anywhere on a circuit proected by a 30 amp breaker?

I was doing some work in an old house I recently moved into, and found that my dishwasher and garbage disposal (and some outlets near them) are on a 30 amp breaker. However, some of the electrical ...
7
votes
2answers
7k views

Can I install an additional breaker bus bar on my main breaker panel?

I'm adding several new circuits to my main electrical panel as part of a kitchen remodel. The panel with accommodate the new circuit breakers, but it does not appear to have enough neutral and ground ...
7
votes
2answers
4k views

How much should it cost to add a circuit breaker?

In this question, I asked about problems between my circuit breaker for a circuit shared by my microwave and sump pump. The conclusion was that another circuit should be added to support the microwave ...
7
votes
2answers
1k views

How can two different breakers both turn off the same circuit?

I have a 40 yr old home with circuit breakers. While looking for the breaker to turn off a circuit (I was replacing a light switch), I found that two breakers, on the same side of the bus, but ...
7
votes
2answers
417 views

What is the best short-term solution for fused neutrals?

I have inherited a house that has been in my wife's family since 1860. I do not know when it was electrified, but it seems to have skipped knob and tube. There is a lot of fabric-covered wire, and ...
6
votes
4answers
6k views

How can I tell if a circuit breaker is worn out?

I was installing a light and tripped the breaker (in retrospect, should have turned the breaker off before starting). When I finished installing it I reset the breaker and tried the light switch. ...
6
votes
1answer
2k views

GFCI outlet won't come on

I have a couple recently installed (By a professional licensed electrician) GFCI outlets outside a barn, both on their own circuit. Both have water trough heaters plugged into them - 1500 watts each. ...
6
votes
7answers
3k views

How important is circuit breaker breaking capacity?

All else being equal circuit breakers can have different "breaking capacity" - it's the maximum current which the breaker can disconnect and it's typically several thousand amperes. The idea is that ...
6
votes
2answers
3k views

Blown fuse replaced, still no power

Yesterday a contractor was doing work in our bedroom. At one point he plugged in a hammering drill and when he used it it blew the fuse. We confirmed the 15amp fuse was dead but I didn't have a ...
6
votes
1answer
197 views

Is it okay two breakers are controlling the same outlets and appliances?

To be specific, we recently had some electrical work done. The electrician added a second panel. He left without labeling anything. So today I've been testing outlets and switches trying to figure out ...
6
votes
2answers
1k views

What is the difference between Square D and QP single pole circuit breakers, and can they be mixed?

I just noticed that all of the branches from my upstairs service box are run off of 15 or 20-amp type QP circuit breakers, except for one 15-amp line that is for the hard-wired smoke alarms- it uses a ...
6
votes
1answer
2k views

Why did my electric range wiring burn out at the terminal block?

Turned on our 2 year old stove (Whirlpool Gold) and heard fizzing noises, then smelled electrical burning. Went downstairs and shut off the breaker (40 amp). That was the only way to get it to stop ...
6
votes
1answer
24k 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, ...
5
votes
3answers
3k views

Does turning circuit breakers off cause wear?

A comment over on another SE got me thinking. With screw-in fuses, unscrewing it and then later screwing it back in causes negligible wear on either part of the installation. But what about modern ...
5
votes
2answers
2k views

Why doesn't the main breaker shut off power for house?

Location: California | United States I'm certain I'll need a licensed electrician for this but wanted to get thoughts on what could be going on. I recently noticed that power remains on in my house ...
5
votes
4answers
829 views

Can re-closing a circuit-breaker be dangerous?

I have a circuit breaker that keeps tripping. When i try to reset (close) it, it immediately jumps back to the open position with a noise that sounds a little scary. I have now stopped trying to do ...
5
votes
1answer
724 views

What is the primary function of the main breaker in a breaker box? How does it differ from other breakers?

Location: California | United States I'd like to better understand the roles of main breakers and sub-breakers. Why are there multiple levels of breakers? I suspect that sub-breakers are intended to ...
5
votes
1answer
974 views

Can i run my cables from the outside box to the inside breaker box through 2x4 studs?

I am turning our carport into a living room and we have a 100amp breaker box outside that feeds power into the breaker box on the inside of our house. the conduit is going to be in the way of the wall ...
4
votes
5answers
2k views

How Do I Power A 220 Water Heater Off Two 110 Breakers

First off I know this is not the best idea. To start my 200 Amp Main has suffered a partial failure and as it is old (60s) and unusual it will be very hard or impossible to replace it. Since the main ...
4
votes
3answers
9k views

How do I replace a GFCI receptacle in my bathroom?

we're remodeling our bathroom and were simply looking to switch out 20 year old light almond outlets and light switches for white. While I thought this would be easy I've run into a problem with the ...
4
votes
3answers
2k views

Why does my 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 ...
4
votes
2answers
2k views

How can I determine which outlets belong to which circuit?

I'm putting in a powerline Internet adapter for my house (something like this). My mom said it has two circuit breakers, but she has no idea how the house is divided between them. Going across ...
4
votes
2answers
3k views

low voltage from circuit - bad breaker?

Background: I'm doing some rewiring work in the kitchen. There were three circuits coming into a junction box that controlled the sink disposal, dishwasher, a few receptacles and a light. So I got ...
4
votes
2answers
254 views

When replacing a circuit breaker in the service panel, how can I determine which neutral is associated with the hot wire?

In my service panel I would like to upgrade two standard circuit breakers with AFCI breakers. AFCI circuit breakers differ from standard circuit breakers in that you attach the hot an neutral to the ...
4
votes
3answers
5k views

Splitting a circuit breaker into multiple lines

I recently found out that several rooms in my house are apparently connected to one circuit breaker. Setup: My wife was in the bathroom drying her hair and I decided it was time to nuke lunch in the ...
4
votes
1answer
501 views

How can I figure out why my breakers are tripping?

A few years ago, I installed a solid wood "pocket" sliding door for my workshop. It's on an exterior wall, so I had to add some thick sealing strips that keep the cold air from Wisconsin winters ...
4
votes
3answers
755 views

Why did my circuit blow after replacing a switch?

I replaced an older switch yesterday on an existing line of recessed lights. There are five lights on the one switch. On the same breaker; but different switch, there are 7 more recessed lights (all ...
3
votes
2answers
2k views

What information do I need to select a circuit breaker?

I am having 2 new lines run in my basement to power a workbench's tools and an unrelated computer station. I have room in my panel for additional breakers, and rather than tie into existing wiring, I ...
3
votes
5answers
495 views

Using a 30-amp tandem circuit breaker for a 120/240v circuit?

I inherited a main panel box from a homeowner that wasn't always fond of meeting the required NEC codes. As such, there are some oddities in the panel. One such oddity is the fact that he installed ...
3
votes
3answers
665 views

What ampacity circuit breaker would I need for an 18 amp electric heater?

What ampacity circuit breaker would I need for an 18 amp electric heater? Here's a link to the model (IEP-4024), it's North American, 240 volts, 4000 watts, installing it outdoor.
3
votes
3answers
4k views

Why won't my AC system turn off after I flipped the breaker?

We've got a central cooling air conditioner that was installed in 1984 with a thermostat from that same year. We are replacing the thermostat with a new programmable one (which has a 100% ...
3
votes
4answers
2k views

What is causing my circuit breaker to trip instantly and trip the next breaker too? Update - Video Added

One of my circuit breaker trips instantly. I try to reset it but it trips immediately and trips the breaker under it too. I can reset the break next to it and it is fine until I try to reset the ...
3
votes
2answers
11k views

What are the differences between SDS, SDS Plus, and SDS Max drills?

Basically I had to use a breaker last weekend, it was clear I did not need the “heavy duty” as I did not have 6” of solid concrete, but the descriptions of the other options confused me.
3
votes
1answer
201 views

Can I wire a secondary 240V breaker box for lab equipment from Europe?

I have a dental lab in Europe and might want to move it to the USA. Some of the equipment rates as high as 4kW, and the the total maximum draw is 15kW for the whole lab. Can I wire a secondary breaker ...
3
votes
2answers
2k views

Why does the breaker trip occasionally after I installed a new light fixture?

We bought a house a couple of years ago with a covered light fixture box in the ceiling (a blank cover over a wired box and a blank cover over the switch box). I recently modified a plug-in pendant ...
3
votes
1answer
244 views

Single outlet resettable breaker?

Basically I have an uninterrupted power supply (UPS) which has a 20amp plug and I know that the load on the UPS will NEVER exceed 15 amp (Bought it mainly because it can attach more battery units to ...
3
votes
3answers
694 views

How do I determine if adding an air conditioner will overload a circuit?

I'm going to take advantage of some Memorial Day sales and pull the trigger on a portable AC unit for my "basement-ish" (bottom of windowsill is mid chest, rather than head height) apartment. Before ...
3
votes
1answer
287 views

What are my options to repair a broken tab on a bus bar?

My A/C went out this week. The problem was a broken tab on a bus bar with cut power to one phase of the 220v circuit. My HVAC guy was able to get me going again by swapping the A/C unit to the dryers ...