Submersible motor pumps (100 mm)
8 Trouble shooting
8.1 Motor
Motor cannot be started
Motor fails, fuses have blown or motor has tripped
Overload protection is actuated after long operation
Repeated starting of the motor
Motor is not cut off (automatic control is not in
function). Applicable only to pressure booster pumps.
Possible cause Remedies
• Voltage is too low / no voltage Retighten loose connections, Contact
electrical supply authority.
• Motor winding or supply cable is damaged Repair / replace motor, cable
• Fuses or automatic switches are not suitable Replace fuse or switch
• Supply voltage is either too high or too low Change either supply or motor if wrong
than rated internal connections are made
• • Failure of a phase (single phasing in 3 Rectify loose connections. Replace fuses.
phase motor) Consult electrical authority.
• Switchgear positioned in too warmer place Protect switchgear from heat
• Control switch is not in function Repair / replace the control device
(level switch / level guard)
• • Leakage in the unit / faulty pressure gauge Trace leakage and seal it
• Extremely high momentary load Dismantle pump, clean & repair
(pump is silted up deeply etc.)
• Contaminated filter, excessive wear in Dismantle pump, clean & repair
pumping unit
• Incorrect co-ordination of pump & pressure Correct the co-ordination
tank (applied to booster pumps)
• Pump components are clogged. Pump should be repaired. To prevent such
incidents the pump-set should not be idle
for a long time. It should be operated at least
once in a week.
8