Panel Feeder Calc

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Can I CORRECTLY size the feeder and the breaker in the existing panel based on what given here? I guess if I just use a 400A feeder I'd be safe?


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Sure.
The new panel show 0 va.
Does show a new unit with an 80 amp breaker.
Nothing against feeding the panel with a smaller feeder as long as it carries the load.

Personally I would RFI the feeder.
Hopefully you can get a 400 in that 600 with out changing it out. Any idea what panel PP is. That's a starting point.

Edit:
I see the new has a 400 amp main. If the 600 has feed thru lugs you may be able to do a tap. Be sure to size the tap conductors for 400 amps.
 
Alwayslearningelec said:
here? I guess if I just use a 400A feeder I'd be safe?
Click to expand...
400 amp bus and 400 amp main so a 400 amp feeder is likely what they want. What it doesn't show is how it connected in the existing PP-EQ-1 panel. Since they're next to each other and there is a main CB a tap could work. A 400 amp tap would require 600 kcmil conductors if there is a 400 amp OCPD in PP-EQ-1 then 500 kcmil would be sufficient.
 
Tulsa Electrician said:
Sure.
The new panel show 0 va.
Does show a new unit with an 80 amp breaker.
Nothing against feeding the panel with a smaller feeder as long as it carries the load.

Personally I would RFI the feeder.
Hopefully you can get a 400 in that 600 with out changing it out. Any idea what panel PP is. That's a starting point.

Edit:
I see the new has a 400 amp main. If the 600 has feed thru lugs you may be able to do a tap. Be sure to size the tap conductors for 400 amps.
Click to expand...
No schedule for PP.
 
To my understanding, feeders only need to be sized to the calculated load (215.2(A)(1)) and supplied with appropriate OCP (215.3). According to that drawing the calculated load is zero.

Install whatever you want. 12awg on a 20 amp breaker should be fine.

If the customer wants something else, then they are asking for something beyond the NEC requirement, which is totally fine, it just means that you're asking a customer expectation question, not a code question.
 
Are these bid documents? This looks like a snipping of a Revit panel schedule that hasn't been filled out.

There is so much missing information I'm not sure how you bid this. Can you RFI for clarification?
 
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