MAINTENANCE
Troubleshooting
10
Troubleshooting
Problem
Probable Causes
Corrective Action
Motor Fails to Start or
Not Running
Motor thermal protector
tripped
Correct cause for high amperage, such as low voltage or excessive pumping.
Open circuit breaker or blown
fuse
Check electric wiring and motor for short circuits and correct.
Impeller binding
Remove pump case and check for debris.
Motor improperly wired
Check complete suction line and all fittings for air leaks and verify foot valve
has adequate submergence.
Defective motor
Take to an authorized motor shop for repair or replacement.
Little or no discharge
Pump is not primed: air or
gases in pumpage
Check suction line and foot valve for leaks. Make sure that water level has not
dropped to uncover suction inlet. Prime pump.
Discharge or suction plugged
or valve closed
Clear obstructions from suction and discharge lines.
Incorrect rotation (3 Phase
only)
Interchange any two of three wires either at the motor or starter.
Low voltage or phase loss
Correct incoming power to match motor nameplate requirements.
Impeller worn or plugged
Clean or replace impeller.
System head too high
Reduce system head (back-pressure on pump) or resize pump.
Excessive suction lift or losses,
or NPSHA too low for the
pump
Locate pump closer to the water source, increase pipe size or resize pump.
Low pump capacity or
pressure
Valves in suction or discharge
lines partially closed
Open valves to reduce possible restrictions.
Suction or discharge line par
-
tially plugged
Clear obstructions from discharge line.
Wrong pump rotation
Correct to proper rotation.
Excessive power con
-
sumption
Impeller binding
Remove pump case and check for debris.
Discharge head too low creat
-
ing excessive flow rate
Close down discharge valve to increase pressure and throttle back flow rate.
Fluid viscosity: specific gravity
too high
Modify fluid properties or resize pump.
Excessive noise and
vibration
Impeller binding
Remove pump case and check for debris.
Pump is not primed: air or
gases in pumpage
Check complete suction line and all fittings for air leaks and verify foot valve
has adequate submergence.
Discharge or suction plugged
or valve closed
Clear obstructions from suction and discharge lines.
Impeller worn or plugged
Clean or replace impeller.
Excessive suction lift or losses.
NPSHA too low for the pump
Locate pump closer to the water source, increase pipe size or resize pump.
Discharge head too low, creat
-
ing excessive flow rate
Close down discharge valve to increase pressure and throttle back flow rate.
Worn bearing
Check bearing for damage and replace if necessary.
Pump, motor, or piping loose
Verify all connections and mountings are secure and piping supported.
Water leakage at pump
shaft
Defective seal assembly
Replace seal.
Summary of Contents for BT4 Series
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