Electric drive fire pump

[sunloco]

I saw a selection table about electric drive fire pump (FM approved ,U.L. listed) In this table I found that BHP of most fire pump is higher than electric motor HP.
for example : capacity :500GPM,rated pressure :210Psi, the BHP(brake Horsepower) is 112 HP, the electric motor fitted is only 100 HP.(motor service factor is 1.15,ODP )

I think there is a little overload though factor is 1.15,motor may be overheat and burnt out if long time running .but this pump was approved by FM and listed by UL. thus anyone has any comment about this problem???

 

[1969grad]

I am told that a 100 HP motor with a 1.15 service factor is really a 115 HP motor. Operating in the service range means that you have no continguency for unforseen conditions.

Where is the point on the pump curve where the 112 HP is required? If it is near shutoff then you would be OK as the operating point is further out on the curve and will require less power.

My opinion is that a fire pump will operate for only a few hours at most and is not a continuous duty pump. The fire will either be out or the facility will be done.

I do question the validity of using an electric motor instead of a diesel engine for a fire pump unless it is a secondary pump. The possibility of the loss of electric power during a fire is something that you need to consider.

 

[sunloco]

"Where is the point on the pump curve where the 112 HP is required? If it is near shutoff then you would be OK as the operating point is further out on the curve and will require less power."


you means if the operating point is closed to the end of the curve ,and it will ok??

by the way ,didn't you think of the power loss of coupling connection or others ? if the BHP is 112kw ,I think it is still dangerous for overload .

 

[Artisi]

The main idea behind a fire pump is that hopefully it never runs other than for periodic maintenance and if it short have to run because of a fire demand it would normally only run for a short period of time.
I believe that any motor with a serviced factor can run into this area for a period of time without undue problems, and as you are speaking of a firepump - how long is it likely to run for in the case of a fire 10 minutes maybe an hour or so - so therefore it stands to reason it should not present any problem.

Naresuan University
Phitsanulok
Thailand