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Discussion Starter · #1 ·
Would you be able to get a current reading if you clamped around a piece of conduit that contained a MWBC (2 hots, 1 neut) ?

And would that reading be different or the same if you clamped around the conductors only?
 

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Would you be able to get a current reading if you clamped around a piece of conduit that contained a MWBC (2 hots, 1 neut) ?

And would that reading be different or the same if you clamped around the conductors only?
I agree no reading either way. Clamp around each hot conductor and subtract their difference, assuming single phase, then that difference should equal the current on the neutral. Otherwise if you clamp around them all it should be zero as it should all cancel
 

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If the conduit is metal, you'll never get a reading.

If it's plastic, then it will be the same as if you clamped around NM cable or SO cord.
 

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The only current you'll read is the leakage to ground from that PVC box with the splice that you buried in your flower bed and thought no one knew about!!:laughing::laughing:
 

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Discussion Starter · #6 ·
Regardless of MWBC or not, your saying that you would never get a current reading on a piece of emt by clamping around it unless there was current flowing on the conduit itself?
 

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Regardless of MWBC or not, your saying that you would never get a current reading on a piece of emt by clamping around it unless there was current flowing on the conduit itself?
You should not have a current reading on the conduit. If you do, there is an electrical problem somewhere in the building, and it might not be the circuits in the conduit you speak of (assuming it's metal).
 

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Discussion Starter · #8 · (Edited)
You should not have a current reading on the conduit. If you do, there is an electrical problem somewhere in the building, and it might not be the circuits in the conduit you speak of (assuming it's metal).
So its not possible to read an inbalance of the conductors inside, rather any reading by clamping around a conduit indicate current flowing on the egc?
 

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So its not possible to read an inbalance of the conductors inside, rather any reading by clamping around a conduit indicate current flowing on the egc?
No it is not possible.
 

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I would clamp the group of conductors associated with the circuit if I was looking for leakage.

Then I would look for a difference of potential between the EGC and the raceway. And EGC to grounded conductor. And grounded conductor and the raceway.

As for clamping the raceway.

I don't think you would get any good info from it. The raceway would be shielding some of the field.

Never tried it myself.

Just looking for geewiz?
 

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Discussion Starter · #12 ·
I think there is some miscommunication here... the conduit is one of the conductors so indeed you would be able to read the sum of the current of the conduit and conductors inside. And if its not balanced then you would get a non-zero reading.



responses like "Its not possible" without an explanation are of little help though.

Thank you.
 

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I don't know where this conversation is going. A clamp meter is used to measure current in current carrying conductors. That means isolating the conductor in question. If you have current in a ground, bond or neutral, it is a troubleshooting issue and a clamp meter is the wrong tool for the job (recognizing, of course, that a clamp meter is also a DMM).
 

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Discussion Starter · #17 ·
I don't know where this conversation is going. A clamp meter is used to measure current in current carrying conductors. That means isolating the conductor in question. If you have current in a ground, bond or neutral, it is a troubleshooting issue and a clamp meter is the wrong tool for the job (recognizing, of course, that a clamp meter is also a DMM).
If there is unbalanced current of the conductors inside the conduit, then I am assuming it is possible to get a reading with a basic ammeter by clamping around the entire conduit.

Just the same, if there is actual current flowing on the gec (this case the conduit) then it would also indicate a reading.

Or is that contrary on how a basic clamp meter works ie: clamping around one conductor at a time.
 

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If there is unbalanced current of the conductors inside the conduit, then I am assuming it is possible to get a reading with a basic ammeter by clamping around the entire conduit.

Just the same, if there is actual current flowing on the gec (this case the conduit) then it would also indicate a reading.

Or is that contrary on how a basic clamp meter works ie: clamping around one conductor at a time.
Explain an "unbalanced" current in a MWBC? The unbalanced current is returning on the neutral conductor. You'll find that by clamping the neutral conductor by itself. You most likely won't get anything by clamping the entire conduit, assuming it's PVC. If you do, you better start troubleshooting.
 

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Type the following into google, read the answers, and THEN, come with your questions.
how an ampere meter works
 
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