Yet another fire pump service question

[VUGear]

Okay, I've reviewed NEC 230.72(B), 230.82(4), 695.3(B), 695.4 and 695.5, as well as NFPA 20 9.2.1.1, 9.2.5.3.1, 9.2.4(2), 9.6 and 9.3.2.2 (and older threads on the subject).

I've got a fire pump combination controller and transfer switch serving one building that has multiple services. It gets 480V emergency power from generator paralleling/synchronization gear. It gets 480V normal power via a tap ahead of the building main, actually at the secondary of the building pad-mount transformer. Additionally the transformer is on a local 12,470V loop with primary metering, fed from two substations via primary switches; note that the transformer thus is not POCO-owned.

Do we understand that the normal power feed to the controller/ATS needs a disconnecting means with overcurrent protection (at locked-rotor) since the fire pump feed is fed from the same building transformer as other protected feeds going into the building? And that if there was a dedicated transformer for the fire pump, then the fusing within the controller would suffice without having to add that additional disconnect?

That's the way the AHJ is presenting it to me.

 

[nakulak]

I'm no expert, but I believe ocpd must meet 695.4 B 1 (2005), not just locked rotor

 

[VUGear]

Right, I'm clear on the requirements for the disconnect when it's required; I'm just trying to figure out if it's required in this case.

 

[RUWired]

So this inspector is requiring an additional disconnect just because the transformer has the normal building loads on it or because the transformer is on a feeder circuit and not a service. What function would it accomplish having two disconnects with OCP. What article is he quoting.

 

[benaround]

Does 240.21(A)(5) come into play here ?

 

[VUGear]

Does 240.21(A)(5) come into play here ?

That may be.

He's saying that otherwise that separate service lateral for the fire pump (i.e. the circuit itself) doesn't have overload protection, apart from the motor overloads found in the fire pump controller. He believes it's very unlikely circuit protection is included, based on the controllers he's seen previously.