Fault Finding The Product - Grundfos SPRING N Series Service Instructions Manual

8. Fault finding the product

DANGER
Electric shock
Death or serious personal injury
- Before removing the terminal box cover and before
removal or dismantling the product, make sure that
the power supply has been switched off and that it
cannot be accidentally switched on.
Fault Cause
1. The motor does not a) Power supply failure.
run when started.
b) The thermal protection device of the motor has
c) The product has not been in use for a long
d) The motor is defective.
2. The product is leaking. a) There is a leakage in the gasket.
b) There is a leakage in the shaft seal.
3. The pump capacity is a) The pump inlet pressure is too low.
not constant.
b) The inlet pipe or product is partly blocked by
c) The product draws in air.
4. The product runs but a) The inlet pipe or product is blocked by
does not deliver the
rated flow.
b) The non-return valve is blocked in closed
c) The direction of rotation is wrong.
d) There is a leakage in the inlet pipe.
e) There is air in the inlet pipe or product.
5. The motor protection a) The power supply is not stable.
triggers frequently.
b) The impeller is stuck.
c) The ambient temperature is too high.
tripped.
time.
impurities.
impurities.
position.
Remedy
Reestablish normal power supply.
Wait until the motor cools down to allowable
temperature. The motor then restarts.
If the motor still cannot start, contact Grundfos.
Switch off the power supply and rotate the motor
non-drive end shaft.
Repair the motor.
Replace the gasket.
Replace the shaft seal.
Increase the liquid level on the inlet side.
Open the isolating valve in the inlet pipe.
Clean the pipeline or product.
Release the air in the pipeline and product.
Clean the pipeline or product.
Clean and open the non-return valve.
Interchange two phases of power supply.
Repair or replace the pipeline.
Check the gasket in the pipe connection, make sure
the gasket works.
Make sure the power supply is stable.
Find the root cause, then repair.
Make sure the ambient temperature is within the
normal range: maximum 40 °C.
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