Gorman-Rupp Pumps VGH4C31-B 1379872 thru 1210169 - Manual (Page 20)

OM−06126 VGH SERIES
TROUBLESHOOTING PAGE D − 2
Table D-1 Troubleshooting Chart (Continued)
TROUBLE POSSIBLE CAUSE PROBABLE REMEDY
PUMP STOPS OR FAILS
TO DELIVER RATED
FLOW OR PRESSURE
(cont.) Impeller or other wearing parts worn
or damaged.
Leaking or worn seal or pump gas-
ket.
Impeller clogged.
Pump running backwards (electric
motor driven models).
Suction lift or discharge head too
high.
Liquid solution too thick.
Replace worn or damaged parts.
Check that impeller is properly cen-
tered and rotates freely.
Check pump vacuum. Replace leak-
ing or worn seal or gasket.
Free impeller of debris.
Check direction of rotation. Correct
3-phase wiring by interchanging any
two motor leads at control box. (See
Pump Rotation in the Installation
and Operations Manual.)
Check piping installation and install
bypass line if needed. See INSTAL-
LATION in the Installation and Op-
erations manual.
Dilute if possible.
PUMP REQUIRES TOO
MUCH POWER Pump speed too high.
Discharge head too low.
Liquid solution too thick.
Impeller jammed due to debris or in-
sufficient clearance.
Check governor setting (engine driv-
en models).
Adjust discharge valve.
Dilute if possible.
Disassemble pump and check impel-
ler.
PUMP CLOGS
FREQUENTLY Discharge flow too slow.
Suction check valve or foot valve
clogged or binding.
Open discharge valve filly to in-
crease flow rate, and run power
source at maximum governed
speed.
Clean valve.
EXCESSIVE NOISE Cavitation in pump.
Pumping entrained air.
Pump or drive not securely
mounted.
Impeller clogged or damaged.
Reduce suction lift and/or friction
losses in suction line. Record vacu-
um and pressure gauge readings
and consult local representative or
factory.
Locate and eliminate source of air
bubble.
Secure mounting hardware.
Clean out debris; replace damaged
parts.