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Copyright © Liberty Pumps, Inc. 2021 All rights reserved.
3473000C
Table 3. Troubleshooting Matrix
Problem
Possible Cause
Corrective Action
Pump does not start.
Damaged power or control cord.
Return pump to an authorized repair facility.
Control panel selector switch in Off position.
Set selector switch to Hand or Auto position.
Blown control circuit transformer fuse.
Replace fuse.
Tripped circuit breaker, blown fuse, or other
interruption of power.
Reset tripped circuit breaker; replace blown fuse with
properly sized fuse; investigate power interruption.
Improper voltage.
Have an electrician check all wiring for proper
connections and adequate voltage and capacity.
Float switch unable to move to the pump ON
position due to interference in basin or other
obstruction.
Position the pump or float switch so that it has adequate
clearance for free movement.
Insufficient liquid level.
Verify the liquid level is allowed to rise enough to
activate float switch(es).
Defective float switch.
Replace float switch.
Obstructed impeller or volute.
Remove obstruction.
Loose wiring connections.
Check and tighten all connections.
Thermal overload tripped.
Wait for pump to cool to operating temperature.
Pump does not start
and overload heaters
trip.
Unintentional ground.
Turn off power and check motor leads for possible
ground.
3-phase motor winding failure.
Check resistance of motor windings. All three phases
should have the same reading.
Obstructed impeller or volute.
Remove obstruction.
Pump operates with
control panel selector
switch in Hand position
but does not operate in
Auto position.
Control circuits malfunctioning.
Check float switch, level control or alternator relay for
issues. Replace as necessary.
Check control panel.
Pump runs but does not
turn off.
Pump is airlocked.
Turn pump off and let set for several minutes, then
restart.
Control panel selector switch in Hand position.
Set selector switch to the Auto position.
Float switch unable to move to the pump OFF
position due to interference with the side of
basin or other obstacle.
Position the pump or float switch so that switch has
adequate clearance for free movement.
Control panel failure.
Check control panel.
Defective float switch.
Replace float switch.
Motor stops and then
restarts after short
period but overload
heaters in starter do not
trip.
Pump operating on a short cycle due to basin
being too small.
A larger basin may be required. Consult Liberty Pumps.
Pump cycles too
frequently.
Improper float switch setting.
Adjust float switch setting.
Check valve not installed, stuck open, or leaking. Install check valve(s); remove check valve and examine
for freedom of operation and proper installation.
