Parallel feeders split to two different power dist blocks within the enclosure

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Dale001289

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Georgia
Construction installed parallel feeders 350kCMIL, 4 per phase into power distribution block that only has two run side entries. So they installed two blocks. Then routed two of the parallels to each block
The load side of each block feeds differing loads from 20A to 100A. It doesn’t look right but thinking about it why wouldn’t this work?


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Obviously reference depends on which Code cycle..but "Conductors in Parallel" in Art 310
 
augie47 said:
Obviously reference depends on which Code cycle..but "Conductors in Parallel" in Art 310
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Construction is arguing that all the loads are intermittent and loading is very light so it doesn’t matter, plus they all go back to the same CB - Admittedly the feeder is significantly oversized


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Their argument may substantiate that there will not be a failure but it does not bring the install into Code compliance.
 
texie said:
Augie is right. Just because it is not likely to burn down, it is still not code compliant.
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Yep. I just have convince our friends in construction it’s noncompliant. Not an easy task. Perhaps you can provide more info on why it’s electrically ‘unfit’ for action?


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augie47 said:
As wired you basically have two 2 conductor feeders l. If the supply breaker is rated higher than the ampacity of either u have a problem
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They’ve agreed to use a different block. However I noticed the block they’ve selected is only rated 10kA while the upstream CB/panelboard are rated 42kA. Does this make a difference?
 
Dale001289 said:
They’ve agreed to use a different block. However I noticed the block they’ve selected is only rated 10kA while the upstream CB/panelboard are rated 42kA. Does this make a difference?
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Could, dependent on the actual available current (not the panel rating) and the current available at the actual distribution block based on the length of the run, etc.
 
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