- Location
- Massachusetts
:ashamed1:
Feed Through Panel Question
- Thread starter kraftymike
- Start date
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:ashamed1:
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
A picture is worth a 1000 words! :rotflmao:
Isn't this just like the ring branch circuits in the UK? I think we've talked about those and whether they could be done under the NEC and what size wire and breaker would be required.
I think if the implementation is legal without the loop, then adding a loop will do no harm and most likely reduce the current in one of the sets of wires. But then the question becomes can wires be paralleled if one wire by itself has sufficient ampacity to carry the load. Would think this would be OK if each panel was fed from a 250A breaker or smaller in the main panel.
I think if the implementation is legal without the loop, then adding a loop will do no harm and most likely reduce the current in one of the sets of wires. But then the question becomes can wires be paralleled if one wire by itself has sufficient ampacity to carry the load. Would think this would be OK if each panel was fed from a 250A breaker or smaller in the main panel.
kraftymike
Member
- Location
- Montana
From what I gather, it's not one bus... it's two. We do not know yet whether each bus is rated for 400A. Additionally, the bus-to-bus connection definitely isn't rated 400A.
Sorry, I haven't been around to check back for a while. This diagram is what I would like to accomplish. 400 amp buss on each panel. 400 amp bus to bus jumpers between. Panels are oriented in such a maner where the conductors would feed perpendicular to the panel wall and all be of equal lengths. If it were legal, I belive it would make an extremely clean installation. So what say the pro's on here? Yay or Nay?
And what is the overcurrent on each panel feeder -- a 200A breaker in the 400A main panel, a 400A breaker in the 400A panel, or feed through lugs from the 400A disconnect? I think I see the error of my ways in my previous post -- one panel could draw double the expected load by taking the max from the upper and lower feeders. If you had 200A breakers feeding each panel, and 400A wire and panels, then it shoudl be OK technically. Not sure what the code says for things connected in a circle.
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kwired
Electron manager
- Location
- NE Nebraska
Why speculate...???
If done like the drawing Smart$ posted there would be no problems as long as the buses are rated 400 amps.
kwired
Electron manager
- Location
- NE Nebraska
I think from what is menioned in the op we definately have a 400 amp breaker as the source of the feed, but the load end of each so called "parallels" do not land on the same device making them an improper parallel conductor according to NEC. It may actually function with little problems but is not NEC compliant. If the panels have feed thru lugs then the drawing submitted by Smart$ is the easiest and least costly way to connect this in an NEC compliant way.
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