FDS or NFDS

[hbmiholl]

Is it required to install a FDS for the input power to Packaged Rooftoop A/C Units that do not have a factory installed disconnect instead of NFDS? All motors in the unit have individual overcurrent protection and the branch circuit is protected as required for short circuit and ground fault. Some inspectors in the City of Los Angeles insist it must be a FDS versus NFDS and I cannot see anything in the NEC that supports it.

 

[websparky]

Re: FDS or NFDS

NEC 2002 440.21
Handbook Commentary;
Where an air conditioner is listed by a qualified electrical testing laboratory with a nameplate that reads ?maximum fuse size,? the listing restricts the use of this unit to fuse protection only and does not cover its use with circuit breakers. If the air conditioner has been evaluated for both fuses and ordinary circuit breakers, or both fuses and HACR-type circuit breakers, it may be so marked. UL-listed circuit breakers that have been found suitable for use with heating, air-conditioning, and refrigeration equipment comprising multimotor or combination loads are marked ?Listed HACR Type.? It is the intent of 110.3(B) to require that the manufacturer's installation specifications be closely followed and that any restriction of the listing be applied to the installation of the equipment, in order to comply with the Code.