Johnson Controls AS Water Pump 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.
Suction pipe not submerged in liquid.
Clearances between impeller/cover and impeller/body have increased. Check and
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.
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.
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.