Grundfos SEG Series, Инструкция по эксплуатации

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17
English (US)
12. Fault finding
Warning
All regulations applying to pumps installed in
potentially explosive environments must be
observed. Make sure that no work is carried out in
potentially explosive atmosphere.
Warning
Before attempting to diagnose any fault, make sure
that the fuses have been removed or the mains
switch has been switched off. Make sure that the
power supply cannot be accidentally switched on.
All rotating parts must have stopped moving.
FM
Fault Cause Remedy
1. The motor does not start. The fuses
blow, or the motor-protective circuit
breaker trips immediately.
Caution:
Do not start again!
a) Supply failure; short-circuit; earth-
leakage fault in the cable or the motor
winding.
Have the cable and the motor checked and
repaired by a qualified electrician.
b) Wrong type of fuse. Install fuses of the correct type.
c) The impeller is blocked by impurities. Clean the impeller.
d) The float switch is out of adjustment or
defective.
Check the float switches.
2. The pump runs, but the motor-
protective circuit breaker trips after a
short while.
a) Low setting of the thermal relay in the
motor-protective circuit breaker.
Set the relay in accordance with the
specifications on the nameplate.
b) Increased current consumption due to
large voltage drop.
Measure the voltage between two motor
phases. Tolerance: - 10 %/+ 6 %.
c) The impeller is blocked by impurities.
Increased current consumption in all
three phases. Clean the impeller.
d) Adjustment of the impeller clearance
incorrect.
Readjust the impeller. See fig. 12 in section
11.4 Adjustment of impeller clearance
.
3. The pump's thermal switch trips when
the pump has been operating for
some time.
a) Too high liquid temperature. Reduce the liquid temperature.
b) Too high liquid viscosity. Dilute the liquid.
c) Wrong electrical connection. (If the pump
is star-connected to a delta connection,
the result will be very low undervoltage). Check and correct the electrical installation.
4. The pump operates at below-
standard performance and increased
power consumption.
a) The impeller is blocked by impurities. Clean the impeller.
Check the direction of rotation. If is not
correct, interchange two phases. See section
10.3 Direction of rotation
.
b) Wrong direction of rotation.
5. The pump runs but gives no liquid. a) The outlet valve is closed or blocked. Check the outlet valve and open or clean it.
b) The non-return valve blocked. Clean the non-return valve.
Vent the pump.
c) Air in the pump.
6. The pump is blocked. a) The grinder system is worn. Replace the grinder system.