Grundfos Fire NKF, Инструкция по установке и эксплуатации

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English (GB)
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16. Fault finding
16.1 Pump set with electric motor
Warning
Before removing the terminal box cover of the
motor, opening the control cabinet or before
starting service work, switch off the power
supply. Make sure that the power supply cannot
be accidentally switched on.
Fault Cause Remedy
1. Pump delivers no
or too little water.
a) Wrong electrical connection. Check the electrical installation.
b) Wrong direction of rotation. Interchange two phases of the power supply.
c) Air in suction pipe. Vent and fill the suction pipe and pump.
d) Counter-pressure too high. Set the duty point in accordance with the data sheet.
Check the system for impurities.
e) Inlet pressure too low. Make sure that all the conditions described in section
9.2 Minimum inlet pressure
and
10.6 Pipe connection
are complied with.
f) Suction pipe or impeller blocked by impurities. Clean the suction pipe or pump.
g) Pump draws in air due to defective seals. Check the pipeline seals, pump housing gaskets and
shaft seals, and replace, if necessary.
2. Motor is
overloaded.
a) Pump blocked by impurities. Clean the pump.
b) Pump running above the rated duty point. Set the duty point in accordance with the data sheet.
c) Motor-protective circuit breaker is not set up
correctly.
Check the setting of the motor-protective circuit breaker
and replace, if necessary.
d) Motor runs on two phases. Check the electrical connection. Replace the fuse, if
defective.
3. Pump makes too
much noise.
Pump runs
unevenly and
vibrates.
a) Inlet pressure too low (cavitation). Ensure that the conditions described in section
9.2 Minimum inlet pressure
and
10.6 Pipe connection
have been met.
b) Air in suction pipe or pump. Vent and fill the suction pipe or pump.
c) Counterpressure is lower than specified. Set the duty point in accordance with the data sheet.
d) Impeller out of balance
(clogged impeller blades).
Clean and check the impeller.
e) Inner parts are worn. Replace defective parts.
f) Pump stressed by the pipework
(causing starting noise). Mount the pump so that it is not stressed.
Support the pipes.
g) Defective bearings. Replace the bearings.
h) Defective motor fan. Replace the fan.
i) Defective coupling. Replace the coupling.
j) Foreign bodies in the pump. Clean the pump.
4. Leaking pump
housing, shaft seal
or connections.
a) Pump is stressed by the pipework (causing
leaks from the pump body or the connections.
Mount the pump so that it is not stressed.
Support the pipes.
b) Pump housing seals or gasket at connections
are defective.
Replace housing seals or connection seals.
c) Shaft seal is dirty or seized up. Clean and check the shaft seal.
d) Shaft seal is defective. Replace the shaft seal.
e) Shaft surface or shaft sleeve is defective. Replace the shaft or shaft sleeve.
5. Too high pump or
motor temperature.
a) Air in the suction pipe or pump. Vent and fill the suction pipe or pump.
b) Inlet pressure is too low. Ensure that the conditions described in section
9.2 Minimum inlet pressure
and
10.6 Pipe connection
have been met.
c) Bearings lubricated with too little, too much or
unsuitable lubricant.
Add or reduce the amount of or replace the lubricant.
d) Pump bearing bracket stressed by the
pipework.
Mount the pump so that it is not stressed. Support the
pipes. Check the alignment of the coupling. See section
10.5 Alignment
.
e) Axial thrust too high. Check relief bores on the impeller and gap rings on the
inlet.
f) Motor-protective circuit breaker is defective or
not set correctly. Check the settings for the motor-protective circuit
breaker, replace if necessary.
g) Motor is overloaded. Reduce flow rate.