Fire pump tap in main service switchboard

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anbm

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We tried to tap the feeder serving the fire pump (in a separate vertical section of a main switchboard, ahead of main breaker section) ...
do we require to install breaker (size with locked rotor current) protecting the fire pump in same section with this feeder tap?
 
anbm said:
We tried to tap the feeder serving the fire pump (in a separate vertical section of a main switchboard, ahead of main breaker section) ...
do we require to install breaker (size with locked rotor current) protecting the fire pump in same section with this feeder tap?
Click to expand...

Assuming that this switchboard is supplied with service conductors (as opposed to a feeder), I'm not sure that OCPD would have to be in that section.
But maybe you don't need the OCPD/disconnect at all. If you can go from the tap to the fire pump controller via a method that is considered outside the building by the NEC you would not need any OCPD/disconnect at the tap, as all full service fire pump controllers are SUSE rated. This can add reliability and save considerable $, especially on larger pump sizes as the size of the disconnect can get quite large to meet locked rotor requirements.
 
I might suggest installing a properly sized UNFUSED disconnect at the fire pump/controller location to make life easier if you ever need to service the fire pump controller or the fire pump itself.
 
gadfly56 said:
I might suggest installing a properly sized UNFUSED disconnect at the fire pump/controller location to make life easier if you ever need to service the fire pump controller or the fire pump itself.
Click to expand...

Haven't been around a lot of fire pumps, but all I have seen the fire pump controller already has an integral disconnecting means and is rated as suitable for use as service equipment.

I do know you don't want any disconnect for the fire pump in the same general vicinity as the normal service disconnect(s), partly because if you had a fire and were wanting to shut down power - you don't want to unintentionally shut down power to the fire pump.
 
kwired said:
Haven't been around a lot of fire pumps, but all I have seen the fire pump controller already has an integral disconnecting means and is rated as suitable for use as service equipment.

I do know you don't want any disconnect for the fire pump in the same general vicinity as the normal service disconnect(s), partly because if you had a fire and were wanting to shut down power - you don't want to unintentionally shut down power to the fire pump.
Click to expand...

IIRC, you can put the fire pump disconnect in the service entrance room, but it shouldn't be in the service panel board and it has to be very clearly labeled.
 
gadfly56 said:
IIRC, you can put the fire pump disconnect in the service entrance room, but it shouldn't be in the service panel board and it has to be very clearly labeled.
Click to expand...
Here is 695.3(A)(1) from 2014

A fire pump shall be permitted to be supplied by a separate service, or from a connection located ahead of and not within the same cabinet, enclosure, vertical switchgear section,or vertical switchboard section as the service disconnecting means. The connection shall be located and arranged so as to minimize the possibility of damage by fire from within the premises and from exposing hazards. A tap ahead of the service disconnecting means shall comply with 230.82(5). The service equipment shall comply with the labeling requirements in 230.2 and the location requirements in 230.72(B)

Red print is text that changed from 2011, according to a note in my E-book version.
 
fire pump tap feeder

fire pump tap feeder

Hi,

We are using 2HR rated MI cable (without conduit) as the tap and feeder conductors for the fire pump.
The issue is that specified wiring is only 3 # 3/0 and 1#4G.
Is a neutral conductor also needed from the tap location to the fire pump service disconnect.

Per 250.66 grounded conductor is required, per my interpretation of code 1#4G will satisfy that code requirement.

This installation is in NYC, but i did not find any specific requirement that NYC enforces to provide neutral for service switch serving fire pump.

Any insight will be helpful.
 
anbm said:
We tried to tap the feeder serving the fire pump (in a separate vertical section of a main switchboard, ahead of main breaker section) ...
do we require to install breaker (size with locked rotor current) protecting the fire pump in same section with this feeder tap?
Click to expand...

I've never been able to figure this out exactly what they want here.

In my opinion, the installation still needs to meet the requirements of 230.70 A 1. You need a service disconnect "nearest the point of entrance of the service conductors".

You also need to meet 230.50 B 1, which doesn't list MI cable.

So unless your fire pump controller is right next to the SWBD, I'd say you need an additional fused disconnect or circuit breaker.

But then there is the section Kwired posted - 230.72(B). The disconnect for the fire pump has to be remote from the other disconnects. So how can it be both "remote", and "closest to the point of entrance"?

The only way I see to meet both requirements is to not install OCP at the switchboard, and then run under the building slab (so the conductors are outside the building), and stub up at the fire controller so the disconnect at the controller is still "closest to the point of entrance."
 
anbm said:
We tried to tap the feeder serving the fire pump (in a separate vertical section of a main switchboard, ahead of main breaker section) ...
do we require to install breaker (size with locked rotor current) protecting the fire pump in same section with this feeder tap?
Click to expand...

I typically provide a tap in a separate vertical section ahead of the main and then provide a fused disconnect switch on the wall in the service room somewhere. This is based on 695.4(B).

However, does 695.4(A) allow me to go directly from the service tap ahead of the main disconnect to the normal side of my ATS without another OCPD?
 
lielec11 said:
I typically provide a tap in a separate vertical section ahead of the main and then provide a fused disconnect switch on the wall in the service room somewhere. This is based on 695.4(B).

However, does 695.4(A) allow me to go directly from the service tap ahead of the main disconnect to the normal side of my ATS without another OCPD?
Click to expand...

Yes. Modern fire pump controllers have suitable disconnecting means built in.
 
steve66 said:
I've never been able to figure this out exactly what they want here.

In my opinion, the installation still needs to meet the requirements of 230.70 A 1. You need a service disconnect "nearest the point of entrance of the service conductors".

You also need to meet 230.50 B 1, which doesn't list MI cable.

So unless your fire pump controller is right next to the SWBD, I'd say you need an additional fused disconnect or circuit breaker.

But then there is the section Kwired posted - 230.72(B). The disconnect for the fire pump has to be remote from the other disconnects. So how can it be both "remote", and "closest to the point of entrance"?

The only way I see to meet both requirements is to not install OCP at the switchboard, and then run under the building slab (so the conductors are outside the building), and stub up at the fire controller so the disconnect at the controller is still "closest to the point of entrance."
Click to expand...
Or encase raceway/cable in minimum of two inches of concrete.
 
lielec11 said:
I typically provide a tap in a separate vertical section ahead of the main and then provide a fused disconnect switch on the wall in the service room somewhere. This is based on 695.4(B).

However, does 695.4(A) allow me to go directly from the service tap ahead of the main disconnect to the normal side of my ATS without another OCPD?
Click to expand...
They are still service conductors and need to somehow be routed so they are considered outside the building or be short enough to be acceptable to the AHJ to be considered "nearest point of entry".

ATS would need to be suitable for use as service equipment if it is supplied with service conductor, or possibly designed specifically for fire pump applications - which case it probably still is suitable for use as service equipment.
 
kwired said:
They are still service conductors and need to somehow be routed so they are considered outside the building or be short enough to be acceptable to the AHJ to be considered "nearest point of entry".

ATS would need to be suitable for use as service equipment if it is supplied with service conductor, or possibly designed specifically for fire pump applications - which case it probably still is suitable for use as service equipment.
Click to expand...

I agree with you on the first part of your post.

The ATS is part of an approved fire pump controller, so would I have to contact the manufacturer to ensure the transfer equipment in the pump controller is listed as suitable service equipment?
 
gadfly56 said:
That's what MI cable is for.
Click to expand...

I certainly may be wrong, but it appears from reading 695.6 and 230.6 that MI cable would meet the requirement for "circuit conductors" on the load side of a overcurrent device, but not as "service conductors" except as allowed by 230.70(A)
(as close to point of entry, etc)
 
lielec11 said:
I agree with you on the first part of your post.

The ATS is part of an approved fire pump controller, so would I have to contact the manufacturer to ensure the transfer equipment in the pump controller is listed as suitable service equipment?
Click to expand...
If it is suitable you would sure think it would be marked as such.
 
lielec11 said:
Thinking about it further, I'm not sure if I would trust designing it this way with all the substitutions I see contractors make that aren't in the specs.
Click to expand...
I have limited experience with fire pumps, but I would think it would be an advantage to have it service equipment rated, otherwise it gets more complicated providing proper overcurrent protection as the overcurrent rules are different for fire pumps then the general rules for other motor circuits.

A listed fire pump controller and service conductors supplying it means you don't have to worry about some of those rules - a lot of things you would otherwise need to know is already taken care of in a single listed assembly.
 
augie47 said:
I certainly may be wrong, but it appears from reading 695.6 and 230.6 that MI cable would meet the requirement for "circuit conductors" on the load side of a overcurrent device, but not as "service conductors" except as allowed by 230.70(A)
(as close to point of entry, etc)
Click to expand...

I should have made my assumptions clear. You have a tap ahead of the normal service disconnecting means, to a separate, clearly marked, disconnecting means for the fire pump, co-located in the electrical service room/area meeting the requirements of 695.4(B)(2) and 695.4(B)(1) if necessary. From that point, you can install MI cable as it meets 695.6(B)(3). Sorry for the confusion.
 
gadfly56 said:
I should have made my assumptions clear. You have a tap ahead of the normal service disconnecting means, to a separate, clearly marked, disconnecting means for the fire pump, co-located in the electrical service room/area meeting the requirements of 695.4(B)(2) and 695.4(B)(1) if necessary. From that point, you can install MI cable as it meets 695.6(B)(3). Sorry for the confusion.
Click to expand...

Agree.

And I'm saying I believe the other option is to omit the disconnect, and run the service conductors "outside the building" to the service rated fire pump ATS. Outside the building means under a min. 2" slab, or encased in 2" of brick or concrete.
 
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