Bell & Gossett DN0177 B Domestic Pump Centrifugal Pumps Series C35 - Manual (Page 26)

The pump makes noise
Cause Remedy
The pump is running backwards. Rotation should be clockwise looking down on the motor
toward the pump.
Rotation of three-phase motors can be corrected by
interchanging any two of the three wires.
NOTICE:
Any electrical service should be performed by a qualified
electrician.
The pump is working at a pressure that is lower than that
for which it was designed.
Install a square-headed plug cock or a 3D valve in the
discharge line and throttle until the operating pressure at
the pump approaches the rated pressure of the pump.
Secure the adjustment of the plug cock by tightening the
locknut.
There is a magnetic hum or bearing noise in the motor. Consult an authorized service station of the motor
manufacturer.
The starter chatters. Check and correct possible low line voltage, poor
connections, defective starter coil, or burned contacts.
Temperature is excessive. Correct system conditions.
Air is trapped in the system. Release the trapped air.
Dealer servicing
If trouble occurs that cannot be rectified, contact your local sales and service
representative and be prepared to provide this information:
• Complete nameplate data of the pump and motor
• Suction and discharge pipe pressure gauge readings
• Ampere draw of the motor
• A sketch of the pump hookup and piping
Troubleshooting
24 Domestic ® Pumps Centrifugal Pumps Series B35, C17, C35 Installation, Operation, and Maintenance Manual