I am running a single feeder that will power a air handler (AHU) and and Return Air Fan. (RAF) The AHU nameplate states a FLA of 42A but limits the MOCP device to 50A. The RAF has a FLA of 3.4A.
NEC 430.62 states the protection device for the multiple motor feeder shall not be greater than largest protection device and the sum of all other motors so in this case, the feeder protection device must be 50A (50+3.4).
If it is sized at 50A and my total FLA is 45.4 (42+3.4), won't I overheat my 50A breaker and get false tripping? It seems to me the AHU MOCP device should be greater that 50A since the 42 FLA is comprised of 4 compressors and 2 fans, but I cannot exceed the manufactures specs.
NEC 430.62 states the protection device for the multiple motor feeder shall not be greater than largest protection device and the sum of all other motors so in this case, the feeder protection device must be 50A (50+3.4).
If it is sized at 50A and my total FLA is 45.4 (42+3.4), won't I overheat my 50A breaker and get false tripping? It seems to me the AHU MOCP device should be greater that 50A since the 42 FLA is comprised of 4 compressors and 2 fans, but I cannot exceed the manufactures specs.