Voltage Drop on Bank of three motors 1

[VTabone]

I have a pump skid system with three centrigual pumps in parallel, each driven by a 30 HP squirell cage motors.

Pumps run properly one at a time, but when all three are on we get reduced flow from what we expect and shoudl be accoutned for by increased flow friction.

What would be the effect of a substantial voltage drop (nominal 460 V) on my motor speed, power, torque etc?

 

[waross]

Voltage low enough to affect the flow rate will probably result in Motor burnout.
Flow rate is dynamic. Three pumps will increase the dynamic head. That will decrease the flow, that will change the operating point on the pump curve, that may change the flow rate.
Check
Pump curves.
Flow measuring accuracy.
Actual pipe condition.
Has the friction changed over time.
Are there restrictions or partially closed valves.
If you are powered from a generator and are dragging the frequency down, the supply may be an issue, but i doubt that low voltage is an issue.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

Have you measured the motor currents and voltages?
It would be very informative to have each motor's voltages and currents with one, two, and three pumps running.

Keith Cress
kcress -

http://www.flaminsystems.com