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Questions tagged [electrical-panel]

Panelboards, also known as "electrical panels", "circuit breaker panels", "fuse boxes", "distribution boards", "consumer units", or "load centers". Remember to provide your location. Include photographs of the existing equipment or plans. Questions about individual overcurrent devices (breakers or fuses) should use the [circuit-breaker] tag.

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43 votes
2 answers
27k 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? ...
Harper - Reinstate Monica's user avatar
32 votes
4 answers
153k 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 ...
STW's user avatar
  • 736
32 votes
5 answers
497k 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 ...
MarkD's user avatar
  • 5,125
11 votes
8 answers
185k 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 ...
Jimmy Hoffa's user avatar
25 votes
7 answers
19k views

Panel breakers are alternately 90 V and 140 V

Everything in the house is acting up. The fridge has melted ice, the radio is acting strange, etc. I multimetered the panel box and each breaker is either 90 V or 140 V alternately. I have a plan to ...
drmadef's user avatar
  • 259
10 votes
3 answers
111k 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 ...
MarkD's user avatar
  • 5,125
55 votes
1 answer
16k views

Half my power out, but firing up an appliance turns it back on

Hoping for some much needed help. The other day my lights flickered and half the power and outlets went out in my home. They have gone and off periodically since then, spontaneously shutting off at ...
Jimmy Vincent's user avatar
14 votes
4 answers
9k views

why is a service neutral grounded but not the subpanel-neutral?

I know it's code (refer to NEC 250.24(A)5 and 250.32), but I don't understand why you can't use a bonding jumper to connect the ground bus and neutral bus in the subpanel? I've been told it's because ...
Ben Welborn's user avatar
  • 6,212
10 votes
2 answers
69k views

What modern 20 amp breaker is compatible with my Challenger panel?

I have a bad 20 amp challenger breaker that I need to replace. Can anyone tell me which replacement to buy. Here’s the info from the breaker: 20 Amp Challenger Und.Lab.Inc.Listed Circuit Breaker 1 ...
Tom Singleton's user avatar
0 votes
2 answers
105k views

What wire size for 100 Amp sub panel 100ft in length from 200 Amp main panel?

What wire size for 100 Amp sub panel 100ft from the 200 Amp main panel? Do I have to buy all 3 wires (2 hot and 1 neutral) the same size? Or can neutral wire be smaller size?
pubanitme's user avatar
25 votes
13 answers
147k 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 ...
auujay's user avatar
  • 5,285
8 votes
5 answers
21k views

Can I use #8 wire in a 15 or 20A circuit?

I have a customer with a detached garage/shed unit that wants to install a few outlets and light fixtures/recessed lighting - common residential use, meaning no heavy power tools, washers/dryers, etc. ...
tresstylez's user avatar
7 votes
1 answer
22k views

What is a split bus panel, and how do I recognize it in the field?

I'm having trouble identifying a split bus panel. I design and install Solar systems, and lately (after Mr Wiley gave a few seminars to local inspectors) the local authority having jurisdiction (AHJ) ...
Todd's user avatar
  • 71
7 votes
6 answers
69k 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 ...
Charles Burns's user avatar
7 votes
1 answer
7k views

Why are tandem breakers on shared neutral (MWBC) problematic?

I hear that shared-neutral or multi-wire branch circuits (MWBC) can have issues when used with tandem breakers (also called duplex, twin, cheater or double-stuff breakers). What is the issue there? ...
Harper - Reinstate Monica's user avatar
6 votes
4 answers
15k views

Running NM-B in PVC SCH 40 Conduit from Outdoor Breaker Panel

For space-saving reasons, I have outdoor breaker panels, and most of my branch circuits are wired through the attic down to individual outlets. Currently, the wires run through the wall from the ...
Hari's user avatar
  • 2,210
6 votes
5 answers
33k views

Can a doorbell transformer sit loose inside main panel?

Can a low voltage transformer for a doorbell sit loose (not screwed to anything) inside the main panel or does it have to be affixed somehow? It came with holes but I'd need to drill holes in the ...
amphibient's user avatar
  • 7,515
4 votes
2 answers
2k views

NEC Article 220 load-calculation for entire house

My house was built 32 years ago, with 200 amp electrical service. Since then I have added a number of large electrical loads, and decided I should do a load calculation for the entire house using NEC ...
RustyShackleford's user avatar
22 votes
6 answers
22k views

Weird Power Outage in Certain Rooms- Condominium

Half of the Condo I rent is losing power sporadically, sometimes for minutes other times for hours. We have power loss to our kitchen lights, microwave, outlet above dishwasher, the dishwasher, entire ...
Ashley's user avatar
  • 229
29 votes
7 answers
9k views

How can I add an ammeter and/or voltmeter to my home breaker panel?

In my professional life, I work in datacenters and all of our PDUs have ammeter displays on them. Of course they do: we always want to know how many amps a PDU is using. But in my house, nobody has ...
user227963's user avatar
  • 1,078
17 votes
3 answers
5k views

Bosch Drawer Microwave causes ARC Faults

I have a brand new Bosch Microwave (model: hmd8451uc) installed as the only device on the entire circuit. Anytime I use the Microwave on this circuit, it triggers the breaker's ARC Fault. Breaker (...
Arian F's user avatar
  • 371
13 votes
5 answers
4k views

Square D Homeline AFCI breakers trip for all appliances

I'm trying to install AFCI breakers on my kitchen SABCs (2x 20A circuits), in my Square D Homeline panel. Unfortunately, the breakers trip whenever I try to do anything useful on those circuits. I've ...
peter's user avatar
  • 1,498
8 votes
1 answer
9k views

Do you strip the outer sheath on romex when it enters a load center / breaker box?

I am doing all my own wiring on a new outbuilding (my well pump house) to save money. I want to have an electrician come in afterwards and simply verify that it was done correctly. When you run ...
user avatar
4 votes
1 answer
6k views

320A/400A electrical service panels

I'm in the process of upgrading my electrical service from 200 amps to 400 amps (technically 320A continuous). My electrical utility is Puget Sound Energy (PSE) in Washington State. Although ...
atanamir's user avatar
  • 373
4 votes
2 answers
9k views

How can I get 30 Amps @120V using several 12AWG and/or 14AWG cables?

I'm trying to power a 30 Amp x 120 Volt RV plug near the perimeter of a five-acre property (200' from the breaker panel). I do not want to buy, dig and bury a new 10-gauge UF cable. However, the ...
David Davido's user avatar
3 votes
1 answer
32k views

Two load centers on one meter

A couple of years ago I had a licensed electrician add a second 100 amp load center to my home (the original 100 amp load center, still in use, could accept no additional breakers). He fed the new ...
Frank's user avatar
  • 33
3 votes
2 answers
8k views

Is it possible to trace a wire to a breaker if you don't have access to the conductor?

Short version Is there a device that can clamp around the outside of an insulated electric line (without contacting the copper) and identify the breaker that controls it by sending a signal through ...
mr blint's user avatar
  • 1,870
2 votes
3 answers
27k views

What happens if you don't bond neutral and ground in a main service panel?

I know that we're supposed to bond neutral and ground in the main panel but can't quite understand what the actual danger/problem with this situation is. I also understand why we don't bond neutral ...
Tony DiNitto's user avatar
2 votes
1 answer
683 views

Electrical load calculation to see if I can install heat pump water heater and EVSE

My house is 1940 square feet. Located in Sunnyvale CA. Sunnyvale has this electrical load calculator: https://ecityhall.sunnyvale.ca.gov/cd/images/New%20Electrical%20Panel%20Calc-Fillable.pdf My ...
user162793's user avatar
1 vote
4 answers
29k views

Can I run a sub-panel with only 3 conductors?

I am going to be adding a 3-wire fed subpanel to a dwelling. My understanding of the plan of attack is attached below (Please forgive my crappy, minimalistic MS-Paint schematics). As you'll notice, ...
Gabe Evans's user avatar
1 vote
2 answers
279 views

Neutral on main service breaker?

Beginning of the story was here - Is RC2040M150CH MSP upgradable to 200amps main circuit breaker So now I got QOM2200VH main circuit breaker (200amps) and ready to install it later this week. The ...
Tagar's user avatar
  • 281
1 vote
1 answer
330 views

Is RC2040M150CH MSP upgradable to 200amps main circuit breaker

I have Square-D Main Service Panel RC2040M150CH. Notice the checkbox on the left for this particular model. The preinstalled circuit breaker is QOM2150VH for 150 amps; 200amps equivalent is ...
Tagar's user avatar
  • 281
42 votes
4 answers
27k views

Why is my voltage dropping with load and why is current flowing on my ground wire?

I am not an electrician, but I've been researching a lot recently to try and figure out why my system is behaving so strangely. Main problem: Lights flickering, sometimes quite severely, and ...
Sasha Aickin's user avatar
24 votes
6 answers
17k views

Can a 40amp breaker be used safely and without issue with a 40amp device on 6AWG wire?

We are installing a Cooktop that calls for a 40amp circuit. I was given 6AWG wire (instead of the 8AWG wire I asked for) by mistake. The electrician saw the 6AWG wire (that I had already run) and used ...
Steve Sensabaugh's user avatar
14 votes
2 answers
3k views

Is electrical panel safe after arc flash?

I was trying to install CT clamps on the service wires to my center fed main electrical panel. I used pliers and by mistake torn a bit the insulation on one conductor while the pliers were touching ...
user162793's user avatar
11 votes
6 answers
13k views

Are power outlets in a home out of phase with each other?

I'm working on a science project and there's one aspect of home wiring I need to find out (don't worry, I'm not messing with wiring - this is all on paper). Since 120V outlets in a home can be wired ...
Michael Baker's user avatar
6 votes
2 answers
6k views

Code: How can a transfer switch not switch neutrals?

I'm looking at this Reliance Controls transfer switch. I certainly won't buy it and don't recommend one, but the huge hank of wires going from switch to panel only has one neutral wire in it. How ...
Harper - Reinstate Monica's user avatar
6 votes
4 answers
5k views

Diagnosing instant circuit breaker tripping, with nothing connected

I had a previous question regarding an AC, but now that I have disconnected the AC and the problem remains, I want to diagnose this problem a bit more. First step was seeing if this specific breaker ...
Nelson's user avatar
  • 1,841
4 votes
2 answers
11k views

Cable securing/support, conduit, etc when exiting main service panel: questions

I'm totally confused by this. Looking for any help that anyone can provide. I've attached a photo of the top of my recently-installed (inspection passed) service panel. The top of the panel sits ...
PhilPDX's user avatar
  • 409
4 votes
4 answers
84k views

Distance between floor and breaker panel?

How far off the floor should my circuit breaker box be? I'm changing from a 100 to a 200 amp. The lead in wires are underground and come into the bottom of box making them too short to connect.
Pete's user avatar
  • 41
4 votes
6 answers
21k views

Why is the neutral tied to ground in my home's electrical panel? [duplicate]

What keeps the Electric from shorting to ground? On my electric panel the Neutral is tied to the ground. The ground is a bare copper wire run back to my water main. a. Electricity chooses the path ...
Darin Friesen's user avatar
3 votes
3 answers
5k views

20A home circuit breaker stuck in "TRIPPED" state

If I understand correctly, then the proper circuit breaker reset procedure is TRIPPED->OFF->ON (ie you can't reset the circuit breaker by going directly from TRIPPED->ON state). However, the circuit ...
user2138912's user avatar
3 votes
1 answer
23k views

Three wire vs four wire feed remote sub panel

I am trying to understand how this works and why the code changed. In this case you have a detached shop 250 feet away with no plumbing or other connections to the house with the main panel. The ...
grantr's user avatar
  • 41
3 votes
3 answers
3k views

What brand of circuit breakers can I use in my panel?

I need to replace a circuit breaker in this panel, and I've read that it's important that I get the right breaker for the panel. How do I tell what brand and type of breaker I should get? The only ...
rothloup's user avatar
  • 745
3 votes
3 answers
6k views

Neutral and ground connected to one bus bar in subpanel; should I change?

At my house, there is a subpanel that serves a pool area, served by one 30 amp 240v circuit. The panel, which I think was installed about 30 years ago, has just one bus bar that the neutrals and ...
Sagierian's user avatar
  • 191
3 votes
2 answers
954 views

8 AWG solid EGC in raceway for 100 amp subpanel

I'm adding a 100 amp subpanel to my detached garage and have a question about the EGC I've already pulled through the underground LFNC-B raceway. Taking the advice from a similar post on this forum, I ...
Jon's user avatar
  • 33
3 votes
3 answers
1k views

Will my 125A electrical panel be sufficient for solar, heat pump, EV charger? [closed]

To my understanding, my main service panel is 125A with a breaker of 100A. My subpanel is 100A. I'm in the design stage of installing solar but I'm planning later in the year to install a heat pump ...
user162793's user avatar
3 votes
3 answers
4k views

How can I connect 2AWG cable to my 100A panel?

I have bought a gazebo (closed) that will serve as a studio and I want to place it on the edge of a wood that is approximately 400 feet from my house. I was planning to run underground wiring from my ...
Maureen's user avatar
  • 73
3 votes
7 answers
94k views

Grounding requirements for main panel and subpanel

I recently had my main service professionally upgraded to 200A and had a 60A subpanel installed in my master suite to support future additions. All work passed city inspection, for whatever that's ...
ErikR's user avatar
  • 133
3 votes
2 answers
535 views

Is there any issue with the neutral and ground being connected in this panel?

The picture below shows the electrical panel in a single-family detached home that my wife and I are in the process of purchasing. The home inspector flagged an issue here with the neutral and ground ...
Chad Lieberman's user avatar

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