Heat gain of AC pump motor vs DC 1

[cdxx139]

Hello Electrical Engineers,

We are changing out 3 600 HP DC motor pumps and changing them over to AC. My job is to provide the cooling in the room for this massive heat gain, which comes out to about 500,000 Btu/hr, which may require a 50 ton chiller @ 1.2 kW/ton is 60 kW.

The existing pump house with the DC pumps do not have any cooling system. The DC rectifiers are in another building.

The client is questioning if we dont have a cooling system now with DC motors, then why do we need them when we change them out to AC motors.

My electrical is weak, so if there is an explanation, primer or white paper that I can be directed to, to help, it would be appreciated.

knowledge is power

 

[edison123]

I don't get it. I presume the replacement AC drive panels will be located where the current DC drive panels are? So, the same cooling / non-cooling system for these dc/ac drive panels?

Replacing the DC motors (presumably in a different working atmosphere than the drive panels) with AC motors should produce lesser heat due to absence of brushes and the commutator heating. So, what's the problem here?



Muthu

http://www.edison.co.in

 

[jraef]

One would think that prudent design considerations would mean the environmental criteria would not have relied upon a severely limited use. I would not have done it that way just because of future considerations, proven out by the fact that if they are now considering running the pumps more, that possibility must have always existed. But true, you nay never know what he original designer may have thought, or what constraints they faced (such as budgetary).


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington