CPC-ZA Sanitary Self-Priming Centrifugal Pump Troubleshooting

Possible Malfunctions

What are the main reasons of malfunction of a CPC-ZA Sanitary Self-Priming Centrifugal Pump?

A malfunction in a pump system may be caused by various reasons and is not necessarily the pump itself. Issues with the pipework or other fluid accessories within the system can be contributing factors. Furthermore, if the operating conditions differ too greatly from the provided specification for which the pump was selected for can also be a major contributing factor.

Consequently, it is always recommended to check the following first:

• Has the pump been installed correctly?

• Are the operating conditions still according to the initial specification?

• Are the other fluid accessories within the pipework functioning correctly?

Malfunction Causes and Solutions

In general, the following malfunctions can be identified:

1. Pump provides little or no flow
2. Pump does not reach duty point
3. Pump provides irregular flow
4. Pump leaks
5. Pump vibrates excessively
6. Pump makes too much noise
7. Motor overheats
8. Motor / Pump cuts out on thermal overload
9. Pump has seized

Below is a table of the possible causes and solutions of these malfunctions.

Malfunction									Cause	Solution
1	2	3	4	5	6	7	8	9
	X				X	X			Electrical Connection is defective	Have a qualified electrician check the connections
	X								Wrong Direction or Rotation	Have a qualified electrician revers the direction of rotation of the electric motor
X									Pump is not completely filled with liquid	Fill the pump casing entirely with fluid and fit a non-return valve to the suction side
X	X	X			X				Insufficient Suction Pressure	Increase the suction pressure or lower position of the pump further below the fluid level
	X						X		Pump operating at the wrong speed	Check the motor speed
								X	Contamination or objects are lodged within the pump which are larger than the solids handling capacity	Clean the pump and install a suction filter if necessary
X	X	X							Air in the pipework	Inspect the pipework and avoid upward rising bends in the pipework
	X								Valve in the suction pipework is not completely open	Entirely open the valve
	X								Pump has been selected with too low a delivery pressure	Install a larger pump or install a booster pump
X	X	X						X	Suction pipe or filter is blocked	Clean the suction pipe or filter
			X						Shaft Seal is defective	Replace the Seal
			X						O-Ring is defective	Replace the O-Ring
							X		Liquid Temperature is too high	Decrease the liquid temperature
X							X	X	Impeller is jammed	Unclog the impeller and replace if necessary
				X	X		X	X	Impeller is damaged	Replace the impeller
				X	X	X	X	X	Motor Shaft is bent	Replace the motor
				X	X	X	X	X	Extension shaft is loose	Inspect the extension shaft, reassemble and readjust
				X	X	X	X	X	Bearings are damaged or worn	Replace the motor, for IG(H) replace the bearings.
							X	X	Motor is overloaded	Check the viscosity of the fluid. Switch off the motor and check if the pump does not drag, if so, disassemble and repair.