Fire Pump Service

[blues]

Quick question: If an emergency generator is available on site is the fire pump required to be on the gen set. Even if the utility company service is deemed to be reliable.

thanks Dan Craven

 

[LIM]

Quick question: If an emergency generator is available on site is the fire pump required to be on the gen set. Even if the utility company service is deemed to be reliable.

thanks Dan Craven

Not that I am aware of. NEC only says it must have a reliable source. It is up to the AHJ to make that determination.

2014 Code
695.3 Power Sourc e(s) for Electric Motor-Driven
Fire Pumps
Electric motor-driven fire pumps shall have a reliable source
of power.
(A) Individual Source s. Where reliable, and where capable
of carrying indefinitely the sum of the locked-rotor current of
the fire pump motor(s) and the pressure maintenance pump
motor(s) and the full-load current of the associated fire pump
accessory equipment when connected to this power supply, the
power source for an electric motor driven fire pump shall be one
or more of the following.
The power source for an electric motor–driven fire pump must be
reliable and have adequate capacity to carry the locked-rotor currents
of the fire pump motor and accessory equipment. These two
main requirements ensure that the fire pump operates in the event
of a fire without being accidentally disconnected, and that the fire
pump continues to operate until the fire is extinguished, the fire
pump is purposely shut down, or the pump itself is destroyed.
The determination of whether the serving electric utility is a
reliable source of power is an issue for the AHJ. The following
excerpt of A.9.3.2 in Annex A of NFPA 20 elaborates on several
key characteristics of a reliable power supply:
A.9.3.2 A reliable power source possesses the following
characteristics:
(1) The source power plant has not experienced any shutdowns
longer than 4 continuous hours in the year prior to
plan submittal. NFPA 25, Standard for the Inspection, Testing,
and Maintenance of Water-Based Fire Protection Systems,
requires special undertakings (i.e., fire watches) when a
water-based fire protection system is taken out of service
for longer than 4 hours. If the normal source power plant
has been intentionally shut down for longer than 4 hours
in the past, it is reasonable to require a backup source of
power.
(2) Power outages have not routinely been experienced in
the area of the protected facility caused by failures in generation
or transmission. The standard is not intended to
require that the normal source of power be infallible to
deem the power reliable. NFPA 20 does not intend to
require a back-up source of power for every installation
using an electric motor–driven fire pump. Note that
should the normal source of power fail in a rare event,
the impairment procedures of NFPA 25 could be followed
to mitigate the risk. If a fire does occur during the power
loss, the fire protection system could be supplied through
the fire department connection.
(3) The normal source of power is not supplied by overhead
conductors outside the protected facility. Fire departments
responding to an incident at the protected facility will not
operate aerial apparatus near live overhead power lines,
without exception. A backup source of power is required
in case this scenario occurs and the normal source of
power must be shut off. Additionally, many utility providers
will remove power to the protected facility by physically
cutting the overhead conductors. If the normal source
of power is provided by overhead conductors, which will
not be identified, the utility provider could mistakenly cut
the overhead conductor supplying the fire pump.
(4) Only the disconnect switches and overcurrent protection
devices permitted by 9.2.3 are installed in the normal
source of power. Power disconnection and activated overcurrent
protection should only occur in the fire pump controller.
The provisions of 9.2.2 for the disconnect switch
and overcurrent protection essentially require disconnection
and overcurrent protection to occur in the fire pump
controller. If unanticipated disconnect switches or overcurrent
protection devices are installed in the normal
source of power that do not meet the requirements of
9.2.2, the normal source of power must be considered not
reliable and a back-up source of power is necessary.

 

[ron]

In general it is not.

Some jurisdictions amend that, so for example, in NYC the fire pump needs to be on a diesel gen (except certain residential situations)

 

[Jraef]

<Removed first comment because I was wrong on if there was wording, apparently there is. But the following still holds true for me>

If it is "deemed to be reliable", why then do they even need to have an emergency generator? They have some "emergency" that they consider to be more important than people not being able to get out of a burning building?

 

[gadfly56]

I believe that if you are required to have a Fire Pump, it has to either be a diesel powered pump or if electric, backed up by a generator. It could be it's own dedicated generator, but that seems silly if you have a backup generator already. i know of now provisions allowing for "the utility company service is deemed to be reliable".

And if it is "deemed to be reliable", why then do they even need to have an emergency generator? They have some "emergency" that they consider to be more important than people not being able to get out of a burning building?

Not required unless amended locally. See the excerpt by LIM above (A.9.3.2(2)).