Gorman-Rupp Pumps SF4C 1528832 and up - Manual (Page 22)

TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
MOTOR RUNS, BUT
PUMP FAILS TO
DELIVER RATED
DISCHARGE. 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. Check impeller (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 (3 phase
models, see Pump Rotation, Sec­
tion C).
PUMP RUNS WITH
EXCESSIVE 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-06511 SF SERIES
PAGE D - 2 TROUBLESHOOTING
TROUBLESHOOTING CHART (cont'd)