Generator E-Stop

[dcheser]

if a generator is serving as backup power to a fire pump is the e-stop outside of the generator room/enclosure still required?

 

[tom baker]

90.3 tells us the rules in chapters 1-4 apply generally unless modified by the rules in 5-7. Does the fire pump article modify the estop rule?

 

[dcheser]

Mr. Baker, I have read through Article 695 - Fire Pumps twice the only item I found that could modify the estop rule is 695.14 Control Wiring. 695.14 states that control circuits that extend outside of the fire pump room shall be arranged so that failure of any external circuit shall not prevent the operation of a pump.

If someone were to activate the Estop this would prevent the operation of the fire pump if the pump were running on emergency power.

 

[tom baker]

I should of added this before my post...when I was an electrical instructor I would state the most important rule in the NEC is 90.3
For 695.14 that would be referring to a fire pump controller control circuit.
Yes you are correct on the Estop. I have not installed any generators since that rule went into effect. But the generators I did install prior to, had an estop in the generator control panel, which was integral to the generator and inside a locked door.
I need to look at the language on the estop to see if it needs to be readily accessible.

 

[dcheser]

So per code the generator Estop outside the generator room/enclosure would not apply to the fire pump?

I understand the purpose of the Estop, to allow you to shut off the generator without entering the room/enclosure but in this instance with the fire pump involved we are now placing an Estop in a public area that could prohibit a fire pump from running.

 

[petersonra]

So per code the generator Estop outside the generator room/enclosure would not apply to the fire pump?

I understand the purpose of the Estop, to allow you to shut off the generator without entering the room/enclosure but in this instance with the fire pump involved we are now placing an Estop in a public area that could prohibit a fire pump from running.

I don't see how activation of the estop is a circuit failure.

 

[tom baker]

The NEC does not use the term E-stop. Its just requires a means to turn off the generator. This device is not required to be readily accessible. I would install it in a NEMA enclosure outside of the generator room enclosure and in the enclosure it could be an E Stop. Put a lock on the enclosure, if FD needs access have a key in Knox box. You could tamper the enclosure door, have second set contacts on E Stop that would go to required fire pump alarm system.
And ask your generator supplier how they deal with this as its an issue they are well aware of

 

[dcheser]

Mr. Baker, thank you for your feedback. It has been greatly appreciated!!

The generator supplier was who contacted me and asked that I look into the E-stop. He had concerns over how that would be handled since the fire pump was also connected to the generator.

 

[tom baker]

The generator supplier is calling it an e stop, but that is not what the NEC calls it, which causes some confusion. Here is your chance to educate the generator supplier