fire pump service conductors

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kennym

Member
Location
New Jersey
I have installed a 1800 amp 120/208 service with a lug tap before my main for a fire pump located on the other side of this building. we ran MI cable through the basement and fed the controller as per my MEP engineered drawings, now local inspector says this is a service and must be outside the blgd (concrete encased) i believe this was the correct installation any imput would be appreciated.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: fire pump service conductors

The inspector is correct if the cable in question is on the line side of the fire pump service disconnect. 695.6(A) requires that the service conductors be physically routed outside of the building or installed per 230.6(1) or (2). Your installation does not meet these conditions. If the conductors in question are on the load side of the fire pump service disconnet, then the installation would be ok, as long as the MI cable meets the one hour requirement in 695(B)(3).
Don

[ April 04, 2004, 11:16 AM: Message edited by: don_resqcapt19 ]
 

steve66

Senior Member
Re: fire pump service conductors

It may be easier to add a disconnect for the fire pump than to reroute the cables. If I remember correctly, the disconnect has to be separate from the other building disconnects, and it has to be sized to handle the locked rotor current of the motor. I seem to remember one we did required the conduits to be concrete encased between the disconnect and the pump room, but your MI cable may eliminate that requirement.

Steve
 

jschultz

Member
Re: fire pump service conductors

if you were in chicago doing a retrofit feeder then you could use MI cable as described i believe. Is it straight NEC installation and which year?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: fire pump service conductors

jschultz,
What code section would permit MI cable on the line side of the fire pump service disconnect? Or is this a case where the Chicago code is less stringent than the NEC?
Don
 

jschultz

Member
Re: fire pump service conductors

Originally posted by don_resqcapt19:
jschultz,
What code section would permit MI cable on the line side of the fire pump service disconnect? Or is this a case where the Chicago code is less stringent than the NEC?
Don
Sorry, i misread his original question. I assumed he had a disconnect, when after reading the other replies, it seems he does not. A disconnect is needed. Could he possibly concrete encase the feeder to make it "outside the building"?
 

tom baker

First Chief Moderator
Staff member
Re: fire pump service conductors

A disconnect for a fire pump has to be able to carry the locked rotor current of the fire pump. For example a 100 hp pump that would normally take a 200 ampere disconnect would require an 800 amp to carry locked rotor current for a fire pump application.
 
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