Sizing the grounding conductor when using the tap rule

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NOV

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IDC Electrical Review Engineer
When using the tap rule, is the grounding conductor sized using Table 250.122 or Table 250.102(C)(1)?
 
Unless it's service (which really would not be a "tap") 250.122 but note 240.122(G)
 
Sorry Augie, I may have jumped the gun on my understanding. If I'm tapping a 500A feeder and feeding a 200A ECB, is the tap grounding conductor sized for the 500A or the 200A? Since this ground is upstream of the 200A, it's twisting me up a little.
 
It's sized based on the 500 amp BUT does not need to exceed the phase conductor size.
Your 500 amp OCP would require a #2 equipment ground. Since you are feeding a 200 amp device your phase condutors would be larger than #2 so the full size #2 would need to extend to your device.
IF you happened to be feeding a 60 amp device with a #6, then the EGC could be reduced to a #6.
 
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