SPP Pumps Unistream - Manual (Page 14)

Manual No/Rev
W21-002E / 10
Operators Instructions for
Unistream Centrifugal Pumps
Our policy is one of continuous improvement and we reserve the right to alter specifications at any time
Page 14 of 24
7. Faults and Remedial Action
POTENTIAL FAULT OR DEFECT:
No liquid delivered.
Insufficient liquid delivered.
Liquid delivered at low pressure.
Loss of liquid after starting.
Excessive vibration.
Motor runs hotter than normal.
Excessive noise from pump
cavitation.
Pump bearings run hotter
than normal.
PROBABLE CAUSES
Pump not primed.
Speed too low.
Speed too high.
Air leak in suction
pipework.
Air leak in mechanical
seal.
Air or gas in liquid.
Discharge head too high
(above rating).
Suction lift too high.
Not enough head for hot
liquid.
Inlet pipe not submerged
enough.
Viscosity of liquid greater
than rating
Liquid density higher than
rating.
Insufficient nett inlet head.
Impeller blocked.
Wrong direction of
rotation.
Excessive impeller
clearance.
Damaged impeller.
Rotor binding.
Defects in motor.
Voltage and/or frequency
lower than rating.
Lubricating oil dirty or
contaminated.
Foundation not rigid.
Misalignment of pump and
driver.
Bearing worn.
Rotor out of balance.
Shaft bent.
Impeller too small.