Electrician Talk banner
1 - 20 of 37 Posts

·
Registered
Joined
·
99 Posts
Discussion Starter · #1 ·
Does anybody know any tricks to prove whether a circuit is it home run or not? A former employer used to ring out egc to neutral and if there's continuity then it goes right to panel. But if its a sub panel i dont see how this would work. Obviously im speaking of a 120 v circuit in this case. Thoughts?
 

·
Registered
Joined
·
12,167 Posts
I guess I'm really losing it. This is the 2nd post I've read and not understood the question.

The neutral and ground should have continuity no matter whether it's coming out of the main panel or a sub panel and I don't know what those 2 panels have to do with the home run.

Curious, what do you consider a "home run"?
 

·
Registered
Joined
·
99 Posts
Discussion Starter · #3 ·
I guess I'm really losing it. This is the 2nd post I've read and not understood the question.

The neutral and ground should have continuity no matter whether it's coming out of the main panel or a sub panel and I don't know what those 2 panels have to do with the home run.

Curious, what do you consider a "home run"?
I consider a home run the first wire of a circuit back to its source. And I guess I questioned the sub panel thing because the neutrals and grounds are separate.
 

·
I own stock in FotoMat!
Joined
·
39,115 Posts
I consider a home run the first wire of a circuit back to its source. And I guess I questioned the sub panel thing because the neutrals and grounds are separate.
But a subpanel will also be tied to the main panel.... where they will show continuity. Ohmmeters don't have a set limit on how far down the circuit they work.
 

·
Registered
Joined
·
99 Posts
Discussion Starter · #5 ·
But a subpanel will also be tied to the main panel.... where they will show continuity. Ohmmeters don't have a set limit on how far down the circuit they work.
Thanks for the simple explanation. It makes more sense to me now. In a subpanel the neutral bar and ground bar are just extensions of the main panels ground. I don't know why I didn't fully understand that earlier.
 

·
Registered
Joined
·
2,969 Posts
Does anybody know any tricks to prove whether a circuit is it home run or not? A former employer used to ring out egc to neutral and if there's continuity then it goes right to panel. But if its a sub panel i dont see how this would work. Obviously im speaking of a 120 v circuit in this case. Thoughts?


Are you trying to find some test to prove that a electrical feed comes
only from the main panel ? And not via a sub panel ?

Why do you need to do this ?

Under what conditions is this important ?

The ringing/low ohms method would work
but requires specialist equipment.
 

·
Registered
Joined
·
99 Posts
Discussion Starter · #7 ·
Are you trying to find some test to prove that a electrical feed comes
only from the main panel ? And not via a sub panel ?

Why do you need to do this ?

Under what conditions is this important ?

The ringing/low ohms method would work
but requires specialist equipment.
No im not trying to distinguish if a feed is from a sub or main panel. I do a lot of residential remodeling and wire a lot of hvac equipment. Today there was a circuit that was no longer needed that was a lot closer to the air handler I needed to wire than the panel was, not to mention a picky homeowner and finished basement. So why not re-use this circuit to avoid snaking a new line. That was my thought on the job. And that's why I needed to know if there was anything else on the circuit between the wire I had my ohm meter on and the basement.
 

·
Registered
Joined
·
7,881 Posts
Does anybody know any tricks to prove whether a circuit is it home run or not?
Sure, if you have access to and test every possible receptacle/switch/light/equipment.

There are of course steps you can take to achieve this. Try not to assume anything though.


Today there was a circuit that was no longer needed that was a lot closer to the air handler I needed to wire than the panel was
In this case, turn off the circuit and test every light and recep in the house. Check especially for hidden, added receps or ceiling fans. They will spin really fast for a short time. :jester

This happen often when changing a 120V AH circuit to a 240V circuit. Around here, the AH circuit is generally dedicated but you can't assume that someone, someday didn't tap it so, before we make the swap, we make damn certain that there is nothing else on it.
 

·
Registered
Joined
·
12,167 Posts
Could you use a circuit tracer and just follow the cable? I don't know because I don't own one, just seen y'all talk about it.

What did the abandoned circuit feed?
 

·
Registered
Joined
·
6,203 Posts
Wouldn't the continuity test between neutral and ground achieve this? Have you ran into a situation where it has come back to bite?
If there are receptacles or switches on the circuit, it will still ring through, that's why he is saying turn it off and make sure everything still works.
 

·
I own stock in FotoMat!
Joined
·
39,115 Posts
If there are receptacles or switches on the circuit, it will still ring through, that's why he is saying turn it off and make sure everything still works.
What devices cause continuity between the neutral and ground?

If the ones you use do that, you'd better buy a different brand.
 

·
Registered
Joined
·
12,167 Posts
It was electric heat.
I would think it would be pretty easy to determine if anything else was on that circuit (I'm assuming it was previously a 240V circuit).
 

·
Registered
Joined
·
12,167 Posts
What about putting an ammeter on the circuit ?
If there's current flowing, then there's something on the circuit !
What if something is connected to the circuit but not turned on?
 

·
Registered
Joined
·
12,167 Posts
Then there would not be any current flow , as the circuit would not be complete !
Exactly (my comment was meant to be a rhetorical question, :) )
 
1 - 20 of 37 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top