NFPA 20 interpretation

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Deadfrog

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Ontario Canada
Hi guys, wondering anyone can help clarify a disagreement on a fire pump installation where we both interpret the code a little differently.

Referring to NFPA 20 Chapter 9

We are installing a fire pump in a 3 story building.
There is no backup generator and none is required as they have been deemed to have reliable power and the building size is within the local fire dept. pumping capacities.

The normal source of power though.... We interpret that we would need to pull off power before the main disconnect to the building (and metering cabinet).

Our client interprets the code a little differently, believing that they can pull power from a circuit directly off a power panel (which has a couple disconnects in line before it, ie. main disconnect switch and a disconnect switch for the panel).

Thanks in advance to anyone who can clarify.
Mike V, EIT
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
Deadfrog said:
Hi guys, wondering anyone can help clarify a disagreement on a fire pump installation where we both interpret the code a little differently.

Referring to NFPA 20 Chapter 9

We are installing a fire pump in a 3 story building.
There is no backup generator and none is required as they have been deemed to have reliable power and the building size is within the local fire dept. pumping capacities.

The normal source of power though.... We interpret that we would need to pull off power before the main disconnect to the building (and metering cabinet).

Our client interprets the code a little differently, believing that they can pull power from a circuit directly off a power panel (which has a couple disconnects in line before it, ie. main disconnect switch and a disconnect switch for the panel).

Thanks in advance to anyone who can clarify.
Mike V, EIT
Click to expand...

The same requirement is in the NEC. You are correct, you need to pull off power before any other disconnects. If you have hot sequencing metering, they could come from the same meter cabinet.

The intent is to limit the number of places power to the fire pump can be inadvertently turned off.

You are permitted to put one disconnect in the supply circuit (which you will probably need if you are connecting directly to the service.) That disconnect has to be rated for the locked rotor current of the pump.
 
D

Deadfrog

Member
Location
Ontario Canada
Thanks for the prompt responses, muchly appreciated.

Just another quick question while we are on the topic. Should the fire alarm panel also be run from before the main disconnect then?

Mike V., EIT
 
dkidd

dkidd

Senior Member
Location
here
Occupation
PE
From the ROC:

(Log #1253)
15-157- (700-12(e)): Accept
SUBMITTER: Lawrence A. Bey, Onan Corp.
COMMENT ON PROPOSAL NO: 15-139
RECOMMENDATION: Accept the proposal to delete 700-12(e).
SUBSTANTIATION: This means of power is unacceptable as an
emergency source and should not be identified as such.
PANEL ACTION: Accept.
NUMBER OF PANEL MEMBERS ELIGIBLE TO VOTE: 19
VOTE ON PANEL ACTION: AFFIRMATIVE: 17
'NEGATIVE: Bird, Jensen
EXPLANATION OF NEGATIVE:
BIRD: The Submitter's original Substantiation is seriously
debatable and his proposal presents no data to support deleting this
work practice that has safely and economically served the industry
for many years.
JENSEN: See my Explanation of Negative on Comment 15-156.
 
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