Gorman-Rupp Pumps S4A1-E25 460/3 1396155 and up - Manual (Page 24)

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
MOTOR RUNS,
BUT PUMP FAILS
TO DELIVER
RATED DIS­
CHARGE. Discharge head too high. Reduce discharge head or install
staging adaptor and additional
pump.
Low or incorrect voltage. Measure control box voltage, both
when pump is running and when
shut off.
Discharge throttling valve partially
closed; check valve installed improp­
erly. Open discharge valve fully; check
piping installation.
Discharge line clogged or restricted;
hose kinked. Check discharge lines; straighten
hose.
Liquid being pumped too thick. Dilute liquid if possible.
Strainer screen or impeller clogged. Clear clog(s). Stop pump; back flow
may flush away debris.
Insufficient liquid in sump or tank. Stop pump until liquid level rises.
Worn impeller vanes; excessive im­
peller clearance. Check impeller and clearance (see
PUMP END REASSEMBLY in
Maintenance and Repair, Section
E).
Pump running backwards. Check direction of rotation. If incor­
rect, interchange any two motor
leads at the control box (see Pump
Rotation, Section C).
PUMP RUNS
WITH EXCES­
SIVE NOISE OR
VIBRATION Pumping entrained air. Check liquid level in sump; check
position of pump and liquid level
sensing device(s).
Damaged or unbalanced impeller. Replace impeller.
Discharge piping not properly sup­
ported. Check piping installation.
Impeller jammed or loose. Check impeller.
Motor shaft or bearings defective. Disassemble pump and check mo­
tor and bearings.
Pump is cavitating. Reduce discharge head or restrict
flow on low head applications.
OM-06098 S SERIES PUMPS
PAGE D - 2 TROUBLESHOOTING
TROUBLESHOOTING CHART (cont'd)