Ground wire sizing

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bluecollar84

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What size ground wire would you run in the conduit with multiple circuits I want to run one ground wire?


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I'm assuming u mean an EGC so it would be sized to the largest OCPD protecting the enclosed circuits. So if u had 3 20 amp circuits and 1 60 amp...u would run a #10 cu EGC.

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Keep in mind thats the basic rule but any other EGC sizing adjustment factors from other articles still apply. Essentially you want to size the EGC based on the largest gauge required for the enclosed circuits.

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bluecollar84 said:
What size ground wire would you run in the conduit with multiple circuits I want to run one ground wire?


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What year code book do you have in front of you?

Roger
 
My largest breaker in that conduit is a 2 pole 30 feeding a heat pump so what size egc do I need in that Conduit if I only run one ground wire with multiple circuits ?


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bluecollar84 said:
My largest breaker in that conduit is a 2 pole 30 feeding a heat pump so what size egc do I need in that Conduit if I only run one ground wire with multiple circuits ?


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What did the code article tell you?
 
tkb said:
What did the code article tell you?
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bluecollar84 said:
#12


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petersonra said:
Good answer
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Since the table says this:

Rating or Setting of
Automatic Overcurrent
Device in Circuit Ahead
of Equipment, Conduit,
etc., Not Exceeding
(Amperes)
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Anything over 20A exceeds the column for #12 so looks like you need a #10. I'm still on the 2008 and that's what is says to use. The table has changed some in the 2014 & 17 but says basically the same thing.
 
So in that same conduit I'm feeding a transformer that feeds and controls a 12v led wetnitch pool light . Does that grounding conduct that is with the branch circuit that feeds the pool light transformer I can't connect the ECG to anything else expect the panel board ? Look at 680.24(f)


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Little Bill said:
Since the table says this:





Anything over 20A exceeds the column for #12 so looks like you need a #10. I'm still on the 2008 and that's what is says to use. The table has changed some in the 2014 & 17 but says basically the same thing.
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If his 30 amp breaker is feeding a heat pump it is possible the heat pump branch circuit conductors only need to be 12 AWG and if that is the case the EGC doesn't need to be any larger then the branch circuit conductors, which is also stated within 250.122 (in 2014 NEC, may have been a part of an exception at some point in earlier years)
 
kwired said:
If his 30 amp breaker is feeding a heat pump it is possible the heat pump branch circuit conductors only need to be 12 AWG and if that is the case the EGC doesn't need to be any larger then the branch circuit conductors, which is also stated within 250.122 (in 2014 NEC, may have been a part of an exception at some point in earlier years)
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OP didn't mention MCA, he only said 30A breaker. So that's what my answer was based on.
 
Little Bill said:
OP didn't mention MCA, he only said 30A breaker. So that's what my answer was based on.
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He did mention the 2 pole 30 is for a heat pump. <---CLUE :D

But you are correct in that we should not make assumptions in this trade. Until confirmed #12 was run, #10 EGC it is.
 
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