12 | EN
Copyright © Liberty Pumps, Inc. 2022 All rights reserved.
7550000G
Pump does not deliver proper
capacity.
Discharge gate valve partially closed or clogged.
Check the discharge line for foreign material,
including ice if the discharge line passes
through or into cold areas.
Check valve partially clogged.
Raise liquid level up and down to clear; remove
check valve to remove obstruction.
Incorrect motor rotation.
1-phase: verify capacitor wiring, else consult
factory.
3-phase: correct pump rotation direction. Refer
to section
Low liquid level.
Check liquid level.
Obstruction in pump or piping.
Remove obstruction.
Total head is beyond pump's capability.
Route discharge piping to a lower level. If not
possible, a larger pump may be required.
Consult Liberty Pumps.
Pump runs but does not turn off.
Pump is airlocked.
Turn pump off and let set for several minutes,
then restart.
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 it has
adequate clearance for free movement.
Control panel selector switch in Hand position.
Set selector switch to Auto position.
Control panel failure.
Check control panel.
Defective float switch.
Replace float switch.
Missing or faulty curb stop/swing check valve
allowing system pressure to feed back through
discharge piping.
Verify presence of a curb stop check valve or
replace curb stop/swing check valve assembly.
Pump operates with 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 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.
Missing or faulty curb stop/swing check valve
allowing system pressure to feed back through
discharge piping.
Verify presence of a curb stop check valve or
replace curb stop/swing check valve assembly.
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.
Seal fail light is illuminated.
Lower (outer) seal has been compromised.
Replace lower seal.
Control panel relay sensitivity is incorrect.
Adjust sensitivity dial.
Table 3. Troubleshooting Matrix (continued)
Problem
Possible Cause
Corrective Action