Bell & Gossett DN0177 B Domestic Pump Centrifugal Pumps Series C35 - Manual (Page 25)

Troubleshooting
The pump does not start
Cause Remedy
The power supply has been interrupted, the disconnect
switch is open, or the control switch is improperly
positioned.
Adjust the relevant switch.
The voltage is not correct for the motor. Check the voltage and wiring against the motor
nameplate data.
The starter coil is not correct for the power supply. —
The overload relays in the starter have tripped out.
The ambient temperature may be too high. Reset the overload relays.
The wiring to the control is incorrect, or the connections
are loose.
Adjust the wiring or tighten the connections.
The control signals are for the pump to be "off." —
Pump capacity is reduced
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 total pressure at the pump discharge is too high. Check the pressure requirement. This includes system
back pressure, friction, and static head.
There is excessive suction lift or the piping is incorrect. —
A valve in the pump discharge line or suction line is
closed or throttled too tightly.
A check valve is installed backwards.
—
The impeller eye is clogged with trash. Clean out the impeller eye.
The pump is too small for the system. —
A strainer is dirty and is retarding the flow. Clean out the strainer.
The pump has lost its prime. Release the trapped air in the pump and reprime.
Steam traps are blowing through. This causes condensate
to return at excessive temperatures. This may reduce the
capacity of the pump below its rating, depending on the
unit and type of pump furnished.
Repair or replace the traps.
Excessive temperatures can reduce the capacity of the
pump below its rating.
Use Series B35 pumps for low NPSH conditions.
Troubleshooting
Domestic ® Pumps Centrifugal Pumps Series B35, C17, C35 Installation, Operation, and Maintenance Manual 23