FirePump Grounding

[frostback]

What is the code requirement for fire pump grounding.We have a 75hp 480v 3p pump with a tap
ahead of the main in the swbd thru a 600a disc sw
to the fire pump controller/ats.We also have a 175a
mag only cb on the gen set with a feeder to the fire pump controller/ats.
The feeder size is #1cu 3 or 4 wire?
If 4wire does the neutral stop at the disc sw?
Do we need 4 wire from the gen set bkr?
What bonding or ground wire is required?

 

[sceepe]

Re: FirePump Grounding

A word of caution, nec 2005 695.3.A1 allows you to supply the fire pump from a tap ahead of the service disconnecting means but it can not be within the same cabinet, enclosure or vertical section as the service disconnecting means. If your switchboard is bottom fed, you would do better to come directly from the poco xfmr secondary.

As for the proper grounding, it depends on whether you have a 3 or 4 pole ats. If its a 4 pole, you could then make the 600 amp disconnect a service disconnect means (install main bonding jumper) 4 wires from disconnect to ats. Ground generator and run 4 wires to ats from genset to ats