Service Disc. Sw.

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dvcraven0522

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St. Louis, Missouri
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I have attached a PDF of an existing one line diagram. It shows a 400amp disc. sw. serving to individual panels (1) rated for 200amps and (1) rated for 100amps. This appears to a clear code violation to me. Is that correct?

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What you have is art 240.21 feeder taps there. The overcurrent devices (main breakers) at the load end is required, next question is how long are the tap conductors and maybe even how much can be considered outside the building. Conductors should be large enough the 25 foot tap rule can be used.
 
dvcraven0522 said:
his appears to a clear code violation to me. Is that correct?
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What do you see as the code violation? David mentioned to EGC's being too small. How long are the tap conductors to each panel? Panel A is missing a 4th conductor.
 
dvcraven0522 said:
The feeders are more than 25'.
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If they are outside the building they can be unlimited length. I don't believe NEC specifically mentions it but most AHJ's probably will let you enter a building as long as you keep amount of conductor inside minimal just like you would do with service conductors.

As mentioned the EGC's would need sized for the 400 amp supply side device, or be same size as largest ungrounded conductor if it is smaller than T250.122 result.
 
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