Lowara e-NSCS Serie Montage-, Betriebs- Und Wartungshandbuch Seite 19

Cause
A power phase is missing.
7.5 The electric pump starts, but the thermal
protector trips a varying time after
Cause
There are foreign objects (sol-
ids or fibrous substances) in-
side the pump which have jam-
med the impeller.
The pumps delivery rate is
higher than the limits specified
on the data plate.
The pump is overloaded be-
cause it is pumping liquid that
is too dense and viscous.
The motor bearings are worn.
7.6 The electric pump starts, but the system's
general protection is activated
Cause
A short circuit in the electrical system.
7.7 The electric pump starts, but the system's
residual current device (RCD) is activated
Cause Remedy
There is an ground Check the insulation of the electrical system
(earth) leakage. components.
7.8 The pump runs but delivers too little or no
liquid
Cause Remedy
There is air inside the
pump or the piping.
The pump is not correctly Stop the pump and repeat the prime pro-
primed. cedure.
If the problem continues:
The throttling on the deliv- Open the valve.
ery side is too extensive.
Valves are locked in Disassemble and clean the valves.
closed or partially closed
position.
The pump is clogged. Contact the local sales and service repre-
sentative.
The piping is clogged. Check and clean the pipes.
The rotation direction of Change the position of two of the phases
the impeller is wrong . on the terminal board of the motor or in
the electric control panel.
The suction lift is too high Check the operating conditions of the
or the flow resistance in pump. If necessary, do the following:
the suction pipes is too
great.
e-nscs Installation, Operation, and Maintenance Manual
Remedy
Check the
• power supply
• electrical connection
Remedy
Contact the local sales and service
representative.
Partially close the on-off valve down
stream until the delivery rate is equal
or less than the limits specified on
the data plate.
Check the actual power requirements
based on the characteristics of the
pumped liquid and replace the motor
accordingly.
Contact the local sales and service
representative.
Remedy
Check the electrical system.
• Bleed the air
• Check that the mechanical seal is
not leaking.
• Check the suction pipe for perfect
tightness.
• Replace any valves that are leaking.
• Decrease the suction lift
• Increase the diameter of the suction
pipe
en - Translation of the original instructions
7.9 The electric pump stops, and then rotates
in the wrong direction
Cause
There is a leakage in one or both of the follow-
ing components:
• The suction pipe
• The foot valve or the check valve
There is air in the suction pipe.
7.10 The pump starts up too frequently
Cause
There is a leakage in one or both of the fol-
lowing components:
• The suction pipe
• The foot valve or the check valve
There is a ruptured membrane or no air
pre-charge in the pressure tank.
7.11 The pump vibrates and generates too
much noise
Cause Remedy
Pump cavitation Reduce the required flow rate by partially closing
the on-off valve downstream from the pump. If the
problem persists check the operating conditions of
the pump (for example height difference, flow re-
sistance, liquid temperature).
The motor bear- Contact the local sales and service representa-
ings are worn. tive.
There are foreign Contact the local sales and service representa-
objects inside the tive.
pump.
For any other situation, refer to the local sales and service representa-
tive.
Remedy
Repair or replace the
faulty component.
Bleed the air.
Remedy
Repair or replace the
faulty component.
See the relevant instruc-
tions in the pressure
tank manual.
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