Mike, NEC Section 695-3 states that the
electric motor-driven fire pumps shall have a “reliable source of power” from one of the following:
1. Separate Electric Utility Service, or
2. On-Site Power Production Facility, or
3. Onsite Generator
At our facility, the fire pump is connected
directly to the utility transformer (ahead of and not within the same cabinet, enclosure, or vertical
switchboard section as the service). Couldn’t the power for the fire pump motor be disconnected at
the transformer by the electric utility in the event of a fire? Is this connection ahead of the service
considered a suitable and reliable source of power?
Most modern fire departments bring water
pumpers to the fire and since most buildings requiring a sprinkler system, have a pump hose hook up
outside of the building for the fire department, thus enabling them to disconnect the electricity
to the facility without endangering personnel sent there to extinguish the fire. Therefore, the fire
pumps on site only have to try to contain the fire until fire department personnel arrive.
That's what I have been told, by the Chicago
While the installation does meet the requirements
of the NEC, it may not be the safest way to feed the fire pump. The NEC states that it is not a design
specification and sometimes we need to go beyond what is required to assure an adequate installation.
In this instance, it would seem that a label might be a good idea " DANGER” THIS TRANSFORMER
SERVES THE FIRE PUMP! I know it is not NEC required, but I have had inspectors recommend things like
this and in most cases, I have complied. A good idea is a good idea, and anything that makes it safer
would be a good idea.