Applying 430.53 Several Motors or Loads on One Branch Circuit

C

cppoly

Senior Member
Location
New York
When supplying power to multiple 208V fan coil units with an RLA of 1.5 amps, 2.5 amps, etc., does each FCU require individual short circuit & ground fault protection (i.e. fused at 15 amps in each local disconnect)? Or can a single 15A circuit breaker provide power to multiple FCU's without needing individual SCGF protection at the unit (local disconnect only)?

Applying 430.53(A) Not Over 1 Horsepower, I don't see any guidance on how many fan coil units you can connect in a single 15A circuit. 430.53(B) indicates that the branch circuit will not open. But I don't see this mentioned as a bullet point in 430.53(A). Am I missing something?
 
wwhitney said:
210.20(A) still applies, so as many units as you can while keeping the load at 15A or under. The load is the sum of the FLAs plus 25% of the largest FLA.

Cheers, Wayne
Click to expand...

Thanks, but I'm surprised 430.53(A) doesn't mention tripping the branch circuit short circuit and ground fault device like 430.53(B) does.
 
cppoly said:
Thanks, but I'm surprised 430.53(A) doesn't mention tripping the branch circuit short circuit and ground fault device like 430.53(B) does.
Click to expand...
Each motor is required to have at most a full load rating of 6A, so I infer the presumption is that such a motor will not trip a 15A breaker on normal startup. I agree there's no discussion of starting while other loads are running.

Cheers, Wayne
 
What about providing individual short circuit and ground fault protection at each unit (fused disconnect) or would the fan coil units be protected by the branch circuit breaker?
 
You must log in or register to reply here.
Top