5595000B
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11 | EN
Pump operates noisily.
Piping attachments to building are too rigid.
Replace a portion of the discharge line with
rubber hose or connector.
Incorrect motor rotation.
1-phase: verify capacitor wiring in Figure
1, else
consult factory.
3-phase: correct pump rotation direction. Refer
to section
Pump is being run below minimum head
requirement causing cavitation.
A different sized pump or impeller may be
required. Consult Liberty Pumps.
Foreign objects in the impeller cavity.
Clean the impeller cavity.
Broken impeller.
Consult Liberty Pumps for information
regarding impeller replacement.
Worn bearings.
Return pump to an authorized repair facility.
Pump runs or hums but does not
pump.
Discharge line blocked or restricted.
Check the discharge line for foreign material,
including ice if the discharge line passes
through or into cold areas.
Check valve is stuck closed or installed
backward.
Remove check valve(s) and examine for freedom
of operation and proper installation.
Gate or ball valve is closed.
Open gate or ball valve.
Total head is beyond pump's capability.
Route piping to a lower level. If not possible, a
larger pump may be required. Consult Liberty
Pumps.
Obstructed impeller or volute.
Remove obstruction.
Pump is airlocked.
Turn pump off and let set for several minutes,
then restart.
Add baffle to reduce trapped air bubbles.
Capacitor failure in control panel.
Check capacitors and replace if needed.
Stuck/defective motor contactor in control
panel.
Replace motor contactor.
Pump is not seated correctly in guide rail base.
Lift pump and re-position.
High level alarm triggering.
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.
Table 2. Troubleshooting Matrix (continued)
Problem
Possible Cause
Corrective Action
