Motor Power

[impeller1]

Good day,

We're looking at fitting larger impellers on a few pumps onsite. From manufacturer's testing, according to the performance curves, the pump's Brake Horsepower is 350 HP. Currently the pump's brake horsepower is 314 HP and they use 350 HP motors. Can these new impellers be used with the existing motors as they would now be rated at the same power?

Regards

 

[itsmoked]

Yes. Theoretically. It would all come down to the FLA of the motors. If after the new impellers are installed the motor continues to run at or below its FLA you're good to go. If it's over a wee bit then you have to start considering lots of other variables. Like ambient, motor service factor, and air flow.

You could conceivably go with new impellers and if they are overloading your motors too much just choke the outlet a small amount to reduce the mass-flow.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Are all your parameters stable? Does the temperature and/or specific gravity of your process fluid ever change? Does your dynamic head ever change? Does your suction pressure ever change? Do you really need the extra flow or pressure?
Is it worth it to change impellers? It won't take much of a change in operating parameters to push the motors into overload. If the economics will support changing impellers consider leaving the impellers as is and installing VFDs. You will then be able to run at the full 350 HP regardless of changes in operating parameters.

Bill
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"Why not the best?"
Jimmy Carter