Main Overcurrent Protection

[KMeni]

There is existing 90KVA Dual Output Frequency Converter at 208V 3P 4W.
The Name Plate Rate on the Input FLA is at 287 Amps at 208V. The equipments internal Main Circuit Breaker is fully rated at 400 Amps. The customer wants to feed the Frequency Converter with a 300 Amps from a 600A Main Distribution Panel.

Does the NEC permitt you to feed lower amps to this Frequency Converter.
If not, reference code section.

 

[mcclary's electrical]

a 300 amp feed for a 287 FLA load is not large enough.

 

[Doug S.]

'05 NEC

430.122(A) ckt must be 125%, 430.128 dico. must be 115%, and I would think 430.44 (Orderly shutdown) could be a concern depending on the application.


My 2?
Doug S.