Johnson Controls AS User Manual
27
IM-AS/02.00 GB (0412)
14.0 Trouble shooting chart
The pump does not prime
•
Air has entered the suction piping; check the seals on the fittings and tighten them
sufficiently.
sufficiently.
•
Suction pipe not submerged in liquid.
•
Clearances between impeller/cover and impeller/body have increased. Check and
correct.
correct.
•
No liquid in the pump. Introduce liquid.
•
Reduce loss of suction head; reduce the suction height.
•
Formation of air pockets; eliminate and if necessary fit a valve on discharge.
No flow
•
Pump not primed; (see point 8 and previous point).
•
Pump turning in wrong direction.
•
Suction port obstructed.
•
On-off valves closed.
Insufficient flow
•
Increased system back pressure on discharge side; increase piping diameter.
•
Air entering mechanical seal; check its condition.
•
Viscosity of fluid greater than that specified in the order. Contact manufacturer.
•
Clearances between impeller/cover and impeller/body have increased. Check and
correct.
correct.
Loss of head
•
Back pressure on discharge side has fallen; throttle the suction pipe.
•
Clearances between impeller/cover and impeller/body have increased. Check and
correct.
correct.
Increase in absorbed power
•
Flow rate is lower than required.
•
Pump is turning at higher speed.
•
The impeller does not turn freely. Check it.
•
Viscosity and/or specific weight are higher than stated.
•
Bearings are not in good condition.
Increase in absorbed current
•
The power required has increased (see previous point).
•
Main voltage value has fallen.
•
There is a fault in the electrical system.