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, Model MCA-60-46-AHI. This unit makes use of 250 amp ("F" Frame) molded case circuit breaker (and isolating switch). This construction does comply with NFPA-20, UL-218 and FM-1321/1323 fire pump controller standards.
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 22.214.171.124. 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 126.96.36.199.
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 code. 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).
Re: fire pump OCPD#100132 10/23/0607:35 PM10/23/0607:35 PM
Yoopersup, how do you know it complies with NFPA/NRTL regs? Personal experience with the particular model?
To me such wording as the email used is always a big red flag:
"This construction does comply with NFPA-20, UL-218 and FM-1321/1323 fire pump controller standards."
It does comply? So says who? "NRTL Listed to standard XYZ" is the type of wording I would find more reassuring. I've seen all sorts of equipment that is "designed to meet" or "complies with the requirements of...", that has never been certified by an OSHA-regulated NRTL or other industry-recognized body. In some cases, as inside your own Listed end-use product, it may OK (but more complicated) to use such unrecognized parts.
Re: fire pump OCPD#100135 10/24/0608:57 PM10/24/0608:57 PM
I;ve inspected several units like this. Are you telling me if its a Listed and labled unit you can say no way. Read 695.4 (B)1 A Listed Fire Pump Controller. 695.4 (B) 1 Is for Additional disconnecting means.Read 695.4 COMPLETELY. Not just sections of it.