EGC Tap Size??

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Mike01

Mike01

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When you tap a set of feeders (10? rule) and provide conductors to the disc. Sw. do you size the EGC based on the overcurrent device you are landing in? ex.200A feeder #8 tap to 60A fused disc. Is #10 adequate, same with a 125A feeder tap would #6 be adequate?
 
Mike01 said:
When you tap a set of feeders (10? rule) and provide conductors to the disc. Sw. do you size the EGC based on the overcurrent device you are landing in? ex.200A feeder #8 tap to 60A fused disc. Is #10 adequate, same with a 125A feeder tap would #6 be adequate?
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No.

You must size the EGC from the tap to the discoonects based on the size of the feeder you are tapping but the EGC never has to be larger then the tap condutors.
 
iwire said:
No.

You must size the EGC from the tap to the discoonects based on the size of the feeder you are tapping but the EGC never has to be larger then the tap condutors.
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IIRC, you must size it based on the OCPD protecting the conductors, but not larger than the tap conductors. However if the tap is in a metal raceway that can be used as an EGC, why run a seperate EGC at all?
 
??

??

You must size it based on the OCPD protecting the conductors
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than the overcurrent would be the tapped disc. Sw. correct. Because if you were to base it on the overcurrent ahead of the tapped disc. You would probably have a larger ground than phase conductors.
 
Mike01 said:
Because if you were to base it on the overcurrent ahead of the tapped disc. You would probably have a larger ground than phase conductors.
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Yes that could happen and in that case you would just match the size of the tap condutors.

I don't have my code book handy but I think you will find the rule in 250.122(G).
 
Mike01 said:
than the overcurrent would be the tapped disc. Sw. correct. Because if you were to base it on the overcurrent ahead of the tapped disc. You would probably have a larger ground than phase conductors.
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You seem to have missed part of what i posted.

but not larger than the tap conductors
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petersonra said:
IIRC, you must size it based on the OCPD protecting the conductors, but not larger than the tap conductors.
Click to expand...

I agree and that was also what I was trying to get across. :smile:


However if the tap is in a metal raceway that can be used as an EGC, why run a separate EGC at all?
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Job specifications?

Habit?

Better sleep?
 
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