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#100126 - 10/20/06 05:20 PM fire pump OCPD
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
If the fire pump controller enclosure has an OCPD in it, is it subject to article 695?
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#100127 - 10/20/06 07:48 PM Re: fire pump OCPD
Yoopersup Offline
Member
Registered: 03/04/03
Posts: 822
Loc: Michigan
Yes
Next Question is ,Is it service rated??
Ect ect
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#100128 - 10/20/06 08:45 PM Re: fire pump OCPD
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
I've been told it is not. That the fire pump controller is regulated by NFPA 20.

I have a controller enclosure with a 250 amp OCPD in it. The fire pump is 460 volt, design B, 60 hp, 3 phase, which means the LRA is 435 according to Table 430.151(B).

The engineer of the fire pump controller told me the OCPD is designed to carry 600% of the FLA. He said it would carry this 600% for apx. 8 to 20 seconds.

I am not sure.
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#100129 - 10/21/06 05:31 PM Re: fire pump OCPD
Yoopersup Offline
Member
Registered: 03/04/03
Posts: 822
Loc: Michigan
Is it a Listed & Labled unit??
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#100130 - 10/23/06 02:46 PM Re: fire pump OCPD
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
I'll have to check, but I think so. Does it have to be a listed and labeled unit? Isn't a unit designed by an engineer acceptable?
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#100131 - 10/23/06 02:56 PM Re: fire pump OCPD
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
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
9.5.1.1. 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 9.5.1.1.

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).
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#100132 - 10/23/06 05:35 PM Re: fire pump OCPD
Yoopersup Offline
Member
Registered: 03/04/03
Posts: 822
Loc: Michigan
Put it in . Ul listed and Labeled Service rated Controller.
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#100133 - 10/24/06 03:13 PM Re: fire pump OCPD
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
So I do not need to consider the size of the OCPD in the controller per the NEC requirements?

What about thermal rating versus the time curve rating, as stated in the comment? Is this a correct interpretation for 'indefinitely' as used in article 695?
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#100134 - 10/24/06 03:26 PM Re: fire pump OCPD
electech Offline
Member
Registered: 02/18/02
Posts: 113
Loc: Northern Il
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.
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#100135 - 10/24/06 06:57 PM Re: fire pump OCPD
Yoopersup Offline
Member
Registered: 03/04/03
Posts: 822
Loc: Michigan
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.
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