Hot answers tagged

38 votes

What does "can't mix neutrals" mean, and how would neutrals get mixed?

Neutral is not ground Ground wires are all connected to each other in a big web. That is fine, since grounds do not flow current except during (momentary) fault conditions. Many people think "Oh,...
25 votes

Dimmer without neutral?

Not junk bought mail order Noting that the seller is not Amazon. You're dealing with the ugly side of the platform, which is essentially eBay. It's populated by cheap junk from Alibaba. A quick ...
23 votes
Accepted

Why does my old table saw power switch cut both hot and neutral?

The technique is called double-switching. According to this article, on AC equipment the technique is used to avoid dangerous conditions when hot and neutral are reversed, as often happens with ...
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23 votes

What does it mean if the electric is out in a room, but the breaker is not tripped?

Those outlet testers can be horribly misleading, there are multiple different faults that could cause any particular combination of lights and the ones they print on them are often not the most likely ...
  • 4,445
22 votes
Accepted

Why is this shared-neutral wiring bad?

There's a rule to prevent that shock In a multi-wire branch circuit (which shares neutral), Pigtail neutrals. This is why: so you can remove any device for servicing without severing the neutral ...
22 votes
Accepted

Why would bridging Neutral and Ground trip a GFCI breaker?

You created a ground fault. So it worked exactly as it should have. Rather than the current in the live and the current in the neutral being equal (or within 30 mA for most European RCCBs, 5 mA for ...
  • 153k
21 votes

Can I use a neutral wire from another outlet to repair a broken neutral?

No, you cannot do this. Assuming the nearby outlet you want to borrow neutral from is on a different circuit, you will be overloading its neutral. Even if it is the same circuit, it's very bad ...
  • 6,279
20 votes

Can ground attached to neutral fool a receptacle tester?

The tester can't tell the difference. One way to look at is that electrically, since neutral and ground are already bonded at one location (normally the main panel), the electrons don't know the ...
19 votes

Can I install a new 120v circuit in this panel as configured?

It's a dangerous disaster No. This is not a panel with all 240V-only loads in it. Such a panel would look like that, yes... but this is not one. This is a code dumpster fire. Because in fact many of ...
19 votes
Accepted

How do I check if my outlet's ground and neutral are connected correctly?

Neutral is not Earth They are completely different wires with completely different jobs. Neutral is the normal everyday path for return current. Earth is a fault catcher, it only flows current when a ...
18 votes

240 Volts - No Neutral Required - How does Power Return to Earth?

Power doesn't want to return to earth. It wants to return to source. For natural power, ESD and lightning, yeah, source is earth. However, for human power, source is the transformer or battery. ...
18 votes
Accepted

Are the grounds and neutrals in this electrical subpanel reversed?

Whoever wired this panel simply was not paying attention The installer who wired this panel did not pay attention to the schematic on the label, assuming that removing the bonding strap was enough ...
18 votes

What does "can't mix neutrals" mean, and how would neutrals get mixed?

Mixed neutrals are when the neutral wires on two different circuits are tied together somewhere. For example, a bedroom can have outlets on one circuit, and ceiling lights on a different circuit. The ...
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18 votes
Accepted

Can neutrals be tied together on different circuits?

I found that the neutrals are tied together in this box, is this allowed? Absolutely never. If a box contains 2 different groups of hot wires that do not interact with each other, their neutrals ...
15 votes

Can I use a neutral wire from another outlet to repair a broken neutral?

Absolutely not. That sort of thinking works with safety ground, which does not ever carry current, except during a fault condition (and we hope there aren't 2 independent fault conditions occurring ...
15 votes

Changing out GFCI disconnect for new hot tub

Neutrals and grounds are kept separated everywhere except at the main panel.
  • 13.2k
14 votes

Kitchen Wiring 14 to 12 Neutral

Switches are not circuit breakers (overcurrent protection). They cannot protect wire and do not make it ok to use smaller wire past them. If any 14AWG wire is used, you must downgrade the breaker ...
14 votes

Why does my old table saw power switch cut both hot and neutral?

Probable reason: they made ONE saw assembly and used a motor that could be configured as 110 or 220. For 220 you would break both lines, for 110 you don't need to, but there is nothing saying you can'...
  • 14.5k
14 votes
Accepted

Using 10/2 and/or 8/2 for a 240 only 3-prong

No, that's illegal and has always been illegal. You are confusing neutral and ground, which is understandable since they go to the same place in the main panel. However they are actually different ...
13 votes

Why does this receptacle have the ground tied to the neutral?

Considering there is some amount of either wrong, or maybe just misleading, information regarding your broad question which, in turn, can lead to ambiguities and poor and/or dangerous actions, I, a ...
13 votes

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

A shared-neutral (two hots sharing the same neutral) is also called a multi-wire branch circuit (MWBC). Now to go any further, first, North American power uses a slick trick. It supplies 120V in two ...
13 votes

Alternative GFCI Wiring in Strict 240V Scenario?

Put the GFCI breaker at the supply panel. Done & dusted! Now, I think it’s very prudent (and generally mandated) to have a local disconnect with a GFCI breaker... Not quite right. There is no ...
12 votes

Can ground attached to neutral fool a receptacle tester?

Yes, it will misread. Because magic-8-ball testers are built for one thing: a quick pass/fail test for brand new wiring you just installed. Obviously, in new wiring, you don't have a bunch of the ...
12 votes

When running a bigger wire to deal with voltage drop on a 240V circuit, do I now need to run a neutral as well?

My question is now that I'm running a 30 amp wire and only using 20 amps, do I need to run a neutral to send the unused 10 amps back the supply? There is no 'unused 10 A'. However (and this is ...
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12 votes
Accepted

Sharing Neutrals - How To Correct?

First, technically, the breakers are not #8 and #16. They are actually #4B and #11B. This is important because odd numbered breakers are on one leg of 120 volts and even numbered breakers are on the ...
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12 votes

Rewiring a switch to bring in neutral

First make sure the breaker is 15A. If it is 20A you must use 12/3 cable. The most elegant way to do this is to use the /3 cable as you plan. The wires will be assigned as follows: White = actual ...
11 votes

Why is this shared-neutral wiring bad?

This is actually rather easy to fix The problem is that the light on switch 2 was routed using the hot and neutral from circuit/leg 2, while the switch itself is powered by the hot from circuit 2 but ...
10 votes
Accepted

Why would a 120v circuit work without a neutral?

It's using the earth as a return path You really don't want to do that. Dirt doesn't conduct electricity very well. Your neutral is bonded to ground in your main panel. The power company's ...
10 votes

Dangers of connecting ground to neutral?

Based on further conversation.... this is an emergent condition that is trying to kill you. It hasn't succeeded only because the shock path to source is high-impedance and limiting current flow to ...
9 votes

Kitchen Wiring 14 to 12 Neutral

If you have any #14 wire in the circuit, you have to put a 15 A breaker on it. So, to keep your 20 A breaker, you should use #12 wire everywhere, and run #12 to the switch and lights.
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