Grundfos MTC Serie Instrucciones De Instalación Y Funcionamiento página 12

Fault
1. The motor does not run
when started.
2. The motor-protective circuit
breaker overload trips
immediately when the power
supply is switched on.
3. The motor-protective circuit
breaker overload trips
occasionally.
4. The motor-protective circuit
breaker has not tripped but
the pump does not run.
5. The pump runs but does not
deliver the rated flow.
12
Cause
a) Supply failure.
b) The fuses are blown.
c) The motor-protective circuit breaker
overload has tripped.
d) The main contacts in the motor-
protective circuit breaker are not
making contact or the coil is faulty.
e) The control circuit is defective.
f) The motor is defective.
a) One fuse or one automatic circuit
breaker is blown.
b) The contacts in the motor-protective
circuit breaker overload are faulty.
c) The cable connection is loose or
faulty.
d) The motor winding is defective.
e) The pump is mechanically blocked.
f) The overload setting is too low.
a) The overload setting is too low.
b) The voltage is low at peak times.
a) Check 1 a), b), d) and e).
a) The pump strainer is partly blocked
by impurities.
b) The liquid level in the tank is too
low.
c) The pump rotates in the wrong
direction.
Remedy
Connect the power supply.
Replace the fuses.
Reactivate the motor-
protective circuit breaker.
Replace the contacts or
magnetic coil.
Repair the control circuit.
Replace the pump.
Cut in the fuse.
Replace the motor-protective
circuit breaker contacts.
Fasten or replace the cable
connection.
Replace the pump.
Remove the mechanical
blocking of the pump.
Set the motor-protective circuit
breaker correctly.
Set the motor-protective circuit
breaker correctly.
Check the power supply.
Clean the strainer.
Increase the liquid level.
Change the direction of
rotation of the motor.