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© Copyright 2020 Zoeller
®
Co. All rights reserved.
ELECTRICAL PRECAUTIONS
Before servicing a pump, always shut off the main power breaker to the panel and then disconnect the pump - making
sure you are wearing insulated protective sole shoes and are not standing in water.
Under flooded conditions, contact your local electric company or a qualified licensed
electrician for disconnecting electrical service prior to pump removal.
Submersible pumps contain oils which become pressurized and hot under operating conditions -
allow 2½ hours after disconnecting before attempting service.
CONDITION
A. Pump will not start or run.
COMMON CAUSES
B. Motor overheats and trips overload or blows fuse.
- Incorrect voltage
- Unbalanced power source
- Incorrect motor rotation
- Negative or low head
- Excessive water temperature
- Impeller or seal mechanically bound
- Defective capacitor or relay
- Motor shorted
- Lost one line in a three phase unit
C. Pumps starts and stops too often.
- Check valve stuck open
- Level controls out of adjustment
- Temperature sensor tripping
- Thermal overload switch out of adjustment or defective
- Pit too small
D.
Pump will not shut off.
- Debris under float switch
- Float travel obstructed
- Defective or damaged float switch
- Magnetic starter contacts shorted
- Air lock - check vent hole
E.
Pump operates but delivers little or no water.
- Check for plugged pump housing, discharge
pipe or sticking check valve
- Vent hole clogged or not drilled
- Discharge head exceeds pumps capacity
- Low or incorrect voltage
- Incorrect motor rotation
- Defective capacitor
F.
Drop in head and/or capacity after a period or use.
- Increased pipe friction
- Clogged line or check valve
- Abrasive material & chemical,
deteriorated impeller and pump housing
If the above check list does not uncover the problem, consult the factory - Do not attempt to service or otherwise disassemble pump.
Steps
Check Voltage At
If No Voltage
If Voltage
No. 1
Line terminals in pump's
Check Disconnect switch, line
Proceed to No. 2
control panel
fuse, and/or circuit breakers
L
1
- L
2
- L
3
(3 Phase)
in power supply circuit.
No. 2
Pump motor terminals in
Check for control circuit
Check starting relay
pump’s control panel
voltage.
Check out magnetic
and capacitor (1 phase units).
T
1
- T
2
- T
3
starter contacts, thermal
Check pump for ground
overloads, and float switches
and binding impeller
Service Checklist & Trouble Shooting
