A radial-flow centrifugal cooling water pump is driven by an AC induction motor.
The pump can supply cooling water to several heat loads, all of which are in parallel alignment.
The following pump conditions initially exist:
Pump motor current = 100 amps
Pump flow rate = 400 gpm
Pump suction temperature = 70°F
Four hours later, the motor is drawing 95 amps.
Which one of the following could be responsible for the observed decrease in motor amps?
A. The temperature of the cooling water being pumped decreased to 60°F with no change in pump flow rate.
B. The temperature of the cooling water being pumped increased to 80°F with no change in pump flow rate.
C. Cooling water flow was established to an additional heat load with no change in the temperature of the cooling water being pumped.
D. Cooling water flow was isolated from an out-of-service heat load with no change in the temperature of the cooling water being pumped.
Show Answer
Answer: D
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