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NFPA 25 (3) 30 minutes flow at peak load question

Question asked by dwelch on Sep 5, 2019

Anyone have comments on how they deal with Sentence 3? :


NFPA 25 - For installations having an automatic transfer switch, the following test shall be per-formed

to ensure that the overcurrent protective devices (i.e., fuses or circuit breakers) do not


 (1) Simulate a power failure condition while the pump is operating at peak load

 (2) Verify that the transfer switch transfers power to the alternate power source

 (3) Verify that the pump continues to perform at peak horsepower load on the alternate

power source for  10 minutes for an alternate utility or 30 minutes if the alternate power

source is a standby generator set

 (4) Remove the power failure condition and verify that, after a time delay, the pump is reconnected

to the normal power source


We are preparing to do a new hospital install and putting (750 gpm x 150% x 30 minutes) almost 34,000 gallons of water onto the road in front of the hospital is problematic.