The Thermal Overload Protection Of The Motor Is Triggered Occasionally, Or After The Pump Unit Has Been Running For A Few Minutes; The Pump Unit Runs But Delivers Too Little Or No Liquid; The Pump Unit Turns The Other Way When Turned Off; The Pump Unit Produces Excessive Noise And/Or Vibrations - Xylem Bell & Gossett e-80SCXL Series Instruction Manual

7.5 The thermal overload protection of the motor is triggered
occasionally, or after the pump unit has been running for a few minutes
Cause
It is calibrated at a value too low in relation to the
rated current of the motor
Input voltage outside the rated limits
Unbalanced input voltage
Incorrect working curve (flow rate greater that the
maximum permitted flow rate)
Liquid too dense, presence of solid or fibrous
substances (pump unit overloaded)
Room temperature too high, exposure to sunlight
Pump unit faulty

7.6 The pump unit runs but delivers too little or no liquid

Cause
Motor turns in the wrong direction
Incorrect priming (there are air bubbles in the
suction pipe or in the pump unit)
Cavitation
Check valve locked in closed or partially closed
position
Foot check valve locked in closed or partially
closed position
Delivery pipe throttled
Piping and/or pump unit clogged

7.7 The pump unit turns the other way when turned off

Cause
Check valve faulty
Foot check valve faulty

7.8 The pump unit produces excessive noise and/or vibrations

Cause
Cavitation
Unsuitable anchoring to the ground
Resonance
Anti-vibration joints not installed
Series e-80SCXL INSTRUCTION MANUAL
Remedy
Recalibrate
Make sure the voltage values are correct
Make sure the voltage of the three phases is
balanced
Reduce the required flow rate
• Reduce the density of the liquid and/or
• Remove the solid substance and/or
• Increase the size of the motor
• Lower the temperature at the point od the
thermal overload protection and/or
• Protect against direct sunlight
Send the pump unit to an authorized workshop for
testing
Remedy
Check the direction of rotation and change it if
necessary
Repeat the priming procedure
Increase the NPSH available in the system
Replace the check valve
Replace the foot valve
Remove the throttling
Remove the clogging
Remedy
Replace the check valve
Replace the foot valve
Remedy
Increase the NPSH available in the system
Check the anchoring to the ground
Check the installation
Install anti-vibration joints on the suction and
discharge lines of the pump unit
7 Troubleshooting
29