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,...
30
votes
Accepted
Why are all the neutral wires in a sub panel burnt or melted?
Because NEC 110.14(D) wasn't followed. A torque wrench was not used to set the screw torques. This is why the rule was added to NEC 2014.
Now if the work predates 2014, it was legal and should not ...
26
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 ...
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 ...
- 511
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 ...
- 4,998
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 ...
- 201k
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 ...
- 6,352
21
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
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. ...
19
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 ...
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
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 ...
- 81.7k
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 ...
- 21.1k
17
votes
Electrical - Ground used a Neutral
used the ground wire connected to the oven’s 3-prong receptacle
An oven's 3-prong receptacle has neutral. It does not have ground. Ovens need neutral so the oven light can be 120V and use a ...
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.
- 22.7k
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'...
- 14.8k
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 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 ...
- 584
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 ...
- 12.6k
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 ...
12
votes
Separating Ground and Neutrals in Mainpanel before installing sub panel
The grounds and neutrals do not have to be separated in the main panel if it is, in fact, the main panel. Sometimes there's confusion if you have a main disconnect/breaker outside by the meter. In ...
- 78.7k
12
votes
Why is a ground wire wrapped around the bare portion of a neutral wire at this outlet?
The neutral wire is broken somewhere and that is a bad cheap lazy hack to have that outlet work.
If you remove the ground from that wire and that outlet keeps working and everything else on that ...
- 22.7k
11
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 ...
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