Troubleshooting - Little Giant Simplex 9S-SMPX Owner's Manual

MAINTENANCE

Troubleshooting

Troubleshooting
Problem
Circuit breaker tripped or
power turned off
Pump will not operate
Switch failure
Blocked discharge pipe
Blocked vent pipe
Check valve installed back-
wards
Pump runs, but does Check valve stuck or
not discharge liquid unplugged
Lift too high for pump
Inlet to impeller plugged
Pump is air-locked
Pump is air locked
Pump does not shut off
when operating in
Liquid inflow matches pump
automatic control
capacity
(with External Control
Module)
Defective switch
Loose connection in level con-
trol wiring
Lift too high for pump
Low voltage, speed too slow
Pump does not deliver
rated capacity.
Impeller or discharge pipe is
clogged
Impeller wear due to abrasives Replace worn impeller.
No check valve in long dis-
charge pipe allowing liquid to
Pump cycles continu-
drain back into sump
ally
Check valve leaking
Basin too small for inflow
For technical assistance, parts, or repair, please contact:
800.701.7894 | littlegiant.com
Form 998567 Rev. 001 10/20
Probable Causes Corrective Action
Reset circuit breaker or correct electrical supply
Disconnect electrical power. Remove the piggyback plug from the outlet.
Plug the pump power cable into the outlet. Turn on electrical power. If the
pump operates, the switch is in failure mode.
Clean discharge pipe.
Clean vent pipe. Make sure the air admittance valves are not restricting the
free passage of air in the vent pipe.
Check flow indicating arrow on check valve body to ensure it is installed
properly.
Remove check valve and inspect for proper operation.
Check rating table.
Pull pump and clean.
Consult the pump installation instructions. Make sure the 3/16" hole in the
discharge pipe inside the basin is not present or is blocked to allow air to
escape the pump volute.
Shut power off for approximately 1 minute, then restart. Repeat several
times to clear air from pump. If system includes a check valve, a 3/16" hole
should be drilled in discharge pipe approximately 2" above discharge con-
nections.
Larger pump required.
Disconnect switch, check with ohmmeter, open-infinitive resistance, closed-
zero.
Check control wiring.
Check rated pump performance.
Check for proper supply voltage to make certain it corresponds to nameplate
voltage.
Pull pump and clean. Check pipe for scale or corrosion.
Install a check valve in discharge line.
Inspect check valve for correct operation.
Install larger basin.
Franklin Electric Co., Inc. | Oklahoma City, OK 73157-2010
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