Fire Pump Considerations
- Thread starter electrics
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T.M.Haja Sahib
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One point that comes immediately to mind is there should be no overload protection...........
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
I don't see why that would be a problem. The trans had primary OL protection.
But what about the gen-set huh.??????
Probably be better just to install a diesel fire pump.
After 9-11 I am surprised they even allow new fire pump installations that are not "stand alone"
After Katrina, we also found out that fuel for the engine-driven pumps is hard to come by and we can't have our pumps running. The same results with what you are complaining about!
There will always be a point where one choice is a better decision than the other IMO. If your pocket is deep, why not have both arrangements? Huh?
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
I'm not happy about a lot of the choices made around here to power critical loads in the event of an emergency. Seems like they are designed to handle a failure of local electrical distribution, but not a true emergency situation.
And the problem with diesel is most of the owners never even think about taking care of their fuel. If you have long term storage you really need some kind of polishing system in place.
Lady Engineer
Senior Member
- Location
- New Jersey
I've done several fire pumps, but this is the first I've done in a while. Good Lord, I'm glad for this refresher....
You should tap ahead of the main on your service, and connect directly to the fire pump controller.
Also, size the primary of the a dedicated transformer to the LRA/LRC.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
electrics said:
That is not exactly true.
Short circuit protection is required, while the running overload protection needs to be above LRA.
The code book I have near me is from 2005.
695.4(B) discusses overcurrent protection being limited to providing short circuit protection only (sized per 430.62)
695.4(B)(1) is the first instance of the infamous 'rated to carry LRA indefinitely', which by the way is not applicable to the conductors.
695.5(B) deals with dedicated transformers. It says secondary protection is not permitted, for the primary it is close to 695.4(B)(1).
695.(C)(2) deals with non-dedicated transformers. In this case overcurrent protection is required but, again, it reads similar to 695.4(B)(1).
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
I always worry about the Generator carrying the LRA of an electric fire pump. Not to mention the transfer switch and everything just making it a more complicated machine. Maybe the answer is to have 2 fire pumps 1 Electric and 1 engine driven. I really don't know
After Katrina, how was the Propane supply situation? At least propane in an ASME tank doesn't float away. And propane stores just about forever.
- Location
- Massachusetts
It is not required to carry that.
Joethemechanic
Senior Member
- Location
- Hazleton Pa
- Occupation
- Electro-Mechanical Technician. Industrial machinery
How would you size the breaker at the generator, if the generator supplies the fire pump? What good would a LRA sized breaker do on a fire pump circuit if the generator has a somewhat smaller breaker?
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