Sulzer VMS - Page 27

Installation, Operating and Maintenance Instructions (Original Instructions) 27
VMS Vertical Multistage Pumps
27
Problem Possible cause Possible solution Checkpoints
Malfunction. Internal blockage in the pump. Have the pump inspected by a
certied company.
Pump does not start. No voltage on the power
terminal.
Check the power supply. • Circuit
• Main switch
• Fuses
Check the motor safety relay • Earth leakage switch
• Protective relay
Thermal motor safety switch
triggered.
Reset the thermal motor safety.
Contact the supplier if this
problem occurs more often.
Check if the correct value is set.
Find the correct value (I
nom
) on
the motor nameplate.
The motor is running, but the
pump does not work.
The coupling between pump
and motor shaft is loose (when
applicable).
Tighten the connecting screws
to the required torque.
The pump shaft is broken. Contact the supplier.
Pump supplies insu󰀩cient
capacity and/or pressure.
Outlet and/or inlet shut-o󰀨 valve
is closed.
Open both shut-o󰀨 valves.
There is air in the pump. Vent the pump.
The suction pressure is
insu󰀩cient.
Increase the suction pressure.
Pump rotates in the wrong
direction.
Change over L1 and L2 of the
three phase supply.
The suction line has not been
vented.
Vent the suction line.
Air bubble in the suction line. Install the suction line with pump
end higher than the other end.
Pump sucks air because of
leakage in the suction line.
Repair the leakage.
Water ow too low. So air
bubbles clog up in the pump.
Make sure the ow increases or
use a smaller pump.
The diameter of the suction line
is too small.
Increase the diameter of the
suction line.
Capacity of water meter in
the supply line is too
small.
Increase the capacity of
the water meter.
Foot valve blocked. Clean the foot valve.
The impeller, the di󰀨user
or stage is blocked.
Clean the inside of the
pump.
O-ring between impeller
and di󰀨user is gone.
Replace the o-rings.
O-ring not resistant to the
medium to be pumped.
Replace o-ring by one
with better resistance.