Here is an excerpt of an email I got in response to my concerns.
The controller in question is our S/N 102490, Peerless #692109, our P/N 705066,
This unit makes use of 250 amp ("F" Frame) molded case circuit breaker (and
This construction does comply with NFPA-20, UL-218 and FM-1321/1323 fire pump
For a 60 Hp, 460 Vac fire pump motor, the NEC (NFPA-70) value for Full Load Amps
is 77.0 FLA.
The motor will be either a Starting Code "F" or "G" to comply with NFPA-20 Table
184.108.40.206. This allows the motor locked rotor current (LRA) to be up to 600% of
FLA which is 462 amps. The fire pump motor will also be a NEMA Design "B" to comply with NFPA-20 Clause 220.127.116.11.
Although Table 430.151B does apply to NEMA design "B" motors, the LRA value is
only 565% of FLA. Our Fire pump controllers are designed to the higher 600%
(462 Amp) value. The 250 amp rating of the controller Circuit Breaker (and
Isolating Switch) are it's thermal rating. NFPA-20 requires these devices to be
sized at no less than 115% of motor rated FLA. For this motor,
this is 77 x 1.15 = 88.6 amps. Notice that we're using 250 amp devices rather than the 100 amp frame breakers used by our competitors, and as allowed by
Our breaker trip point will be the required 8 to 20 seconds at LRA (462 Amps), also per the codes. Any devices upstream of the controller (fuses, circuit breakers,
switches), however, must be sized at the 600% value or 462 amps, also per code(NFPA-20 and
Article 695 of NFPA-70).