400Amp rated meter to a bus that feeds a 350A fused disconnect and a 150A fused disconnect

Cartoon1

Cartoon1

Senior Member
Location
Florida
Occupation
Electrical Engineer
Hello,

Type a weird scenario i saw on an existing building. You have a 400Amp rated meter that goes to a bus and the bus feeds a 350A Fused disconnect and a 150A fused disconnect (on an exterior of a building that is feeding two difference suites). The cable to the bus is rated for 400Amps.

I believe it looks code compliant as long as the total load is calculated 400Amps or lower. But wouldn't it be better to size the cable for 500A+ and upgrade the meter to 600A incase the tenants increase their load over time? Technically each unit could pull its rated load in this case (349A+149A) without the breaker tripping. Which will exceed the 400Amp cable rating and the meter rating.
 
infinity said:
Are 349 amps and 149 amps the actual calculated load for the two service disconnects?
Click to expand...
No. The 350A and 150A total loads is calculated to be 360A. (assuming no load was added after this building was built).
 
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