Goulds Pumps 3393 - IOM - Manual (Page 109)

Troubleshooting
Operation troubleshooting
Symptom Cause Remedy
The flow rate is too low. The back pressure is too high. Open the discharge valve a little further.
Reduce the resistance in the discharge
pipe. Clean the filter if necessary.
Use a larger impeller. Make sure to take
note of the available motor power.
The speed is too low. Increase the speed. Check the available
motor power.
Compare the speed of the motor with the
specified pump speed. See the rating
place.
When you adjust the speed (frequency
transformer), check the reference value
settings.
The impeller diameter is too small. Use a larger impeller. Check the available
motor power.
The pump and/or pipes are not complete- Fill the pump and/or pipes with liquid.
ly filled with liquid.
Vent the pump and/or pipes.
The pump or suction/intake pipe is Clean the pipes.
blocked.
There is an air pocket in the pipeline.
Vent the pipes.
Improve the pathway of the pipes.
The NPSH is too low. Increase the liquid level.
Increase the suction pressure.
Reduce the resistance in the intake/suc-
tion pipe. Change the course and pipe
size, open the shutoff valves, and clean
the filters.
Air is being sucked into the pipes. Increase the liquid level.
Check that the suction pipe is vacuum-
tight.
Provide valves and fittings in the suction
pipe with water seal.
The direction of rotation is wrong. Change the motor rotation.
The inner components are suffering from Replace the worn parts.
wear.
Density and/or viscosity of the pumped
Seek assistance
liquid is too high.
The flow rate stops after a period of time. The pump or suction/intake pipe is Clean the pipes.
blocked.
The NPSH is too low.
Increase the liquid level.
Increase the suction pressure.
Reduce the resistance in the intake/suc-
tion pipe. Change the course and pipe
size, open the shutoff valves, and clean
the filters.
Air is being sucked into the pipes. Increase the liquid level.
Check that the suction pipe is vacuum-
tight.
Provide valves and fittings in the suction
pipe with water seal.
The inner components are suffering from Replace any worn parts.
wear.
The density and/or viscosity of the
Seek assistance.
pumped liquid is too high.
Model 3393 Installation, Operation, and Maintenance Manual 107