conductors from ATS to controller

[sberger3]

We are doing a project that involves refeeding a fire pump with a new ATS. There is some confusion in the interpretation of this code.
1)My interpretation of this code section is:
NEC 695.6(A), the exception: requires the load conductors from the ATS to be routed outside the building or routed according to 230.6(1),
1) under 2" of concrete beneath the building or
2) encased in 2" of concrete or brick in a chase.

The 2 hour fire rating pertains to the wiring beyond the final point of disconnect (circuit conductors) NEC 695.6(B).

2) Others are interpreting the code to allow 2 hour fire rated systems for ALL the effected wiring. (not my interpretation)

Which is the correct interpretation of the code, (1) or (2)?

Thank you in advance.
Sheldon

 

[chris kennedy]

Are there "short-circuit protective devices" in the ATS? If so they are no longer service conductors.

 

[sberger3]

My question pertains to the load conductors from the ATS. The service conductors to the ATS do not require any special routing (outside the building etc) as the exception points out.
thanks

 

[Robert Hutcherson]

A good source for fire pumps is the NFPA 20 book on stationary fire pumps. In some installations, Fire Pump controller has a built-in transfer switch. Fire pump installs can be confusing without proper design from an engineer.

Is there a new FP Controller? with internal ATS?

Is the ATS in the same room as the fire pump?

Speaking to the electrical plan review person with AHJ will also shed light on the requirements.

JMTC

 

[Npstewart]

Last fire pump I designed we ran it inside the building. The feeder has to be a 2 hour rated. It usually isn't practical to encase in concrete.

 

[chris kennedy]

My question pertains to the load conductors from the ATS.

Understood, if your normal power switching device in the ATS is a breaker sized for LRC, then the load conductors would no longer be service conductors.

 

[sberger3]

Thanks to everyone for their input.
To answer some of your questions:
1) The ATS is external, new and in the same room as the fire pump
2) Fire pump controller is existing and also in the same room as the existing fire pump,existing controller and new ATS.
Thanks

 

[Robert Hutcherson]

1) Within the fire pump room, read 695.6(B)Exception

2) Pump wiring from the controller, read 695.6(E)

3) It sound like the utility and generator feeders are already in the fire pump room. ? If those feeders were permitted and approved by previous code cycles, assuming they are sized properly per 695.6(C)(1), and OCP is right size, the AHJ may approve as repair or upgrade of the fire pump equipment only. If they go by 2008 for the whole system, there may be considerable additional requirements.

Good luck.

 

[sberger3]

1) Within the fire pump room, read 695.6(B)Exception, ........yes, I understand this section pertains to the wiring after the final point of disconnect

2) Pump wiring from the controller, read 695.6(E), yes, this has to be the 1hr fire rating,...... this section directs to they type of raceway

3) It sound like the utility and generator feeders are already in the fire pump room. ?............. Customer requested the fire pump be on a seperate ATS: we are refeeding the pump with a new ATS.

If I may, back to the question we are not agreeing to is: 695.6(A) Quote:Exception: Where there are multiple sources of supply,with means of automatic connection from one source to another, the requirement shall apply only to conductors on the load side of that point of automatic connection. Does this mean the load side of the ATS must be installed outside the building,encased in 2" of concrete or 2" of brick?

Thanks to everyone for the feedback on a complicated question

 

[sberger3]

Understood, if your normal power switching device in the ATS is a breaker sized for LRC, then the load conductors would no longer be service conductors.

1)I agree for supply conductors, when fed with (1)source,they must be routed as 'service conductors' routed outside the building,without protection and per article 230.

2)When using (2) sources, with an ATS, 695.6(A) exception requires the ATS load conductors from the ATS to be installed in accordance with 'service conductor' requirements of 695.6(A).

Am I interpreting the code correctly?

I appreciate the feedback. Thanks in advance or your response.

 

[yucan2]

1)I agree for supply conductors, when fed with (1)source,they must be routed as 'service conductors' routed outside the building,without protection and per article 230.

2)When using (2) sources, with an ATS, 695.6(A) exception requires the ATS load conductors from the ATS to be installed in accordance with 'service conductor' requirements of 695.6(A).

Am I interpreting the code correctly?

I appreciate the feedback. Thanks in advance or your response.

We've installed numerous fire pumps, jockey pumps and their associated controllers.

Your interpretation is correct.

 

[Robert Hutcherson]

Article 695.3(B)(2)

The two sources they discuss are from 2 different utility services.

It does not apply to (1) utility source and (1) generator source.

Article 695.(B)(3) exception applies for conductors in the fire pump room.

NEC could have written article 695 better.