Troubleshooting - Little Giant WRS-5 Owner's Manual

Troubleshooting

Problem Probable Causes
Diaphragm switch
Weak or hardened rubber dia-
phragm
Plugged vent tube
Dirt or sediment lodged between
retainer ring and rubber
diaphragm causing contacts to
remain closed
Pump will
not shut
off
Pump is air locked
Liquid inflow matches pump
capacity
Defective switch
Loose connection in level control
wiring
Check valve installed backwards
Check valve stuck or plugged
Pump
Lift too high for pump
runs but
Inlet to impeller plugged
does not
discharge
liquid.
Pump is air locked
Lift too high for pump
Pump
Low voltage, speed too slow
does not
deliver
Impeller or discharge pipe is
rated
clogged
capacity.
Impeller wear due to abrasives
Corrective Action
Replace switch.
Replace rubber diaphragm.
Clear vent tube of any obstructions.
Clean area around rubber diaphragm.
Shut power off for approximately 1 minute. Then restart.
Repeat several times to clear air from pump. If system
includes a check valve, drill a
pipe approximately 2 inches above discharge connections.
Larger pump required.
Disconnect switch. Check w/ohmmeter. Open-infinitive
resistance, closed-zero.
Check control wiring.
Check flow indicating arrow on check valve body to insure
it is installed properly.
Remove check valve and inspect for proper operation.
Check rating table
Pull pump and clean.
Shut power off for approximately 1 minute. Then restart.
Repeat several times to clear air from pump. If system
includes a check valve, drill a
pipe approximately 2 inches above discharge connections.
Check rated pump performance.
Check for proper supply voltage to make certain it corre-
sponds to nameplate voltage.
Pull pump and clean. Check pipe for scale or corrosion.
Replace worn impeller.
MAINTENANCE
Troubleshooting
3
/ -inch hole in discharge
16
3
/ -inch hole in discharge
16
7