Fire Pump Connection with Paralleling Gear

Status
Not open for further replies.
F

flengineer

Member
Location
Miami, FL
I have three generators with paralleling gear that feed an emergency switchboard. I need to feed a fire pump, life safety loads, standby loads and optional loads from the generator. Under 2008 NEC, I believe I need to provide the breakers for the LS, SB and OP loads each in a separate section of the switchboard to comply with 700.9(B)(5).

However, how can I feed the fire pump and comply with 695.4(A)?

695.4(A): The supply conductors shall directly connect the power source to either a listed fire pump controller or listed combination fire pump controller and power switch. Where the power source is supplied by on-site generator(s), the supply conductors shall connect to a generator disconnecting means dedicated for the purposes of serving the fire pump. The disconnecting means shall be located in a separate enclosure from the other generator disconnecting means.

I can't tap into the feeder before the switchboard since there are three different generators. Does this not apply if there is a direct connection from a utility and the generator is the secondary source?
 
Follow-up: I spoke to the generator supplier and he informed me that what is typically done is tapping the emergency switchboard bus then feeding a fire pump disconnect outside the enclosure of the emergency switchboard.

1. Can this tap occur in the same section as the incoming power or must it be done in its own section?
2. Each of the three generators has an integral 1000A main line circuit breaker upstream of the switchboard. Does this violate 695.4(A) (2008 edition, which we are under) which states that the generator disconnecting means must be dedicated for the purpose of serving the fire pump? If I eliminate the generator breaker, I have no means to isolate one generator should one of the three require service.
 
flengineer said:
Follow-up: I spoke to the generator supplier and he informed me that what is typically done is tapping the emergency switchboard bus then feeding a fire pump disconnect outside the enclosure of the emergency switchboard.

1. Can this tap occur in the same section as the incoming power or must it be done in its own section?
2. Each of the three generators has an integral 1000A main line circuit breaker upstream of the switchboard. Does this violate 695.4(A) (2008 edition, which we are under) which states that the generator disconnecting means must be dedicated for the purpose of serving the fire pump? If I eliminate the generator breaker, I have no means to isolate one generator should one of the three require service.
Click to expand...
It sure sound like the only way to meet that requirement is to install a separate, lower current, disconnecting means on each generator which serves a separate fire pump bus.
 
GoldDigger said:
It sure sound like the only way to meet that requirement is to install a separate, lower current, disconnecting means on each generator which serves a separate fire pump bus.
Click to expand...

Wouldn't that then require 2 sets of paralleling gear with 1 set dedicated to fire pump service to get the benefit of redundant gensets for fire pump service?
 
eHunter said:
Wouldn't that then require 2 sets of paralleling gear with 1 set dedicated to fire pump service to get the benefit of redundant gensets for fire pump service?
Click to expand...
Yes, since the object is to allow the main breaker to be opened without disconnecting the fire pump connection.
 
Status
Not open for further replies.
Top