hbendillo
Senior Member
- Location
- South carolina
I have read many of the fire pump threads but as much as I read them, I still want some reassurance that I understand everything. Sorry if some of this seems repetitive but I think there are some questions in here that may be helpful for everyone.
I have a fire pump installation for which I am designing power and in reading NEC 695 and references to other NEC sections it leads me to several possibilities for arranging the service for the fire pump and accessory equipment. The conditions for the fire pump electrical services are as follows:
1. The fire pump is part of a high expansion foam type system located in a fuel truck maintenance facility.
2. A separate room is being constructed to house the high expansion foam system equipment and one of the walls of the room is an outside wall. The room actually encloses the high expansion foam system and the existing wet sprinkler system riser.
3. System includes fire pump, jockey pump, fire and jockey pump controllers, and control panel for monitoring and operating the system.
4. The electrical service for the fire pump will be provided by a separate service from a utility transformer.
I have read many of the fire pump threads on the site, and think I have a handle on what is required/allowed, but want to make sure. My goal is to provide a separate electrical service for this room and feed everything in the room from it.
The first option, is to stub the service up on the outside wall of the room, install a wiring trough, and tap the service conductor twice. One for the fire pump controller feed and one for a panel to be installed in the room that feeds the jockey pump and other fire pump accessories. I would show two fusible disconnects tapped from the trough with overcurrent protection sized according to NEC 695 and other related NEC sections. (I.E. fire pump motor service OCP sized for locked rotor current).
The second option would be to locate the wiring trough in the fire pump room. I interpret that the exception to 695.6(A)(2)(d) would allow running the conduit directly into the room without the fire rated protection of the conductors.
One of the things I am not sure of is whether I can set a panel to feed the jockey pump and the other fire pump accessories in the room or whether or not I have to tap the service conductors and feed directly to the jockey pump controller. One limitation I am looking at for the panel is that it may feed only ?Associated Fire Pump Loads? according to 695.6(2)(b).
Other issues I am considering is whether I need to install a disconnect for the fire pump ahead of the controller. According to what I am reading in NEC 695 I should consider tapping the panel off the separate service ahead of the fire pump controller and just bring the service conductors directly into the fire pump controller.
One final question: Is it required to tap and feed the jockey pump and jockey pump controllers from the separate service to the fire pump room or can these loads be fed off the regular building service? 695.4(b)(2)(a) states:
Individual Sources. The overcurrent protective device(s) shall be rated to carry indefinitely the sum of the locked-rotor current of the fire pump motor(s) and the pressure maintenance pump motor(s) and the full load current of the associated fire pump accessory equipment when connected to this power supply. Where?..
The key word in this paragraph is ?when?. Which leads me to think it doesn?t have to be connected to the separate service power supply.
Sorry about the length.
I have a fire pump installation for which I am designing power and in reading NEC 695 and references to other NEC sections it leads me to several possibilities for arranging the service for the fire pump and accessory equipment. The conditions for the fire pump electrical services are as follows:
1. The fire pump is part of a high expansion foam type system located in a fuel truck maintenance facility.
2. A separate room is being constructed to house the high expansion foam system equipment and one of the walls of the room is an outside wall. The room actually encloses the high expansion foam system and the existing wet sprinkler system riser.
3. System includes fire pump, jockey pump, fire and jockey pump controllers, and control panel for monitoring and operating the system.
4. The electrical service for the fire pump will be provided by a separate service from a utility transformer.
I have read many of the fire pump threads on the site, and think I have a handle on what is required/allowed, but want to make sure. My goal is to provide a separate electrical service for this room and feed everything in the room from it.
The first option, is to stub the service up on the outside wall of the room, install a wiring trough, and tap the service conductor twice. One for the fire pump controller feed and one for a panel to be installed in the room that feeds the jockey pump and other fire pump accessories. I would show two fusible disconnects tapped from the trough with overcurrent protection sized according to NEC 695 and other related NEC sections. (I.E. fire pump motor service OCP sized for locked rotor current).
The second option would be to locate the wiring trough in the fire pump room. I interpret that the exception to 695.6(A)(2)(d) would allow running the conduit directly into the room without the fire rated protection of the conductors.
One of the things I am not sure of is whether I can set a panel to feed the jockey pump and the other fire pump accessories in the room or whether or not I have to tap the service conductors and feed directly to the jockey pump controller. One limitation I am looking at for the panel is that it may feed only ?Associated Fire Pump Loads? according to 695.6(2)(b).
Other issues I am considering is whether I need to install a disconnect for the fire pump ahead of the controller. According to what I am reading in NEC 695 I should consider tapping the panel off the separate service ahead of the fire pump controller and just bring the service conductors directly into the fire pump controller.
One final question: Is it required to tap and feed the jockey pump and jockey pump controllers from the separate service to the fire pump room or can these loads be fed off the regular building service? 695.4(b)(2)(a) states:
Individual Sources. The overcurrent protective device(s) shall be rated to carry indefinitely the sum of the locked-rotor current of the fire pump motor(s) and the pressure maintenance pump motor(s) and the full load current of the associated fire pump accessory equipment when connected to this power supply. Where?..
The key word in this paragraph is ?when?. Which leads me to think it doesn?t have to be connected to the separate service power supply.
Sorry about the length.
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