Fault Finding Chart - Homa MX 34 Serie Originalbetriebsanleitung

10. Fault Finding Chart

Before maintenance or repair disconnect the pump
from the power supply to avoid accidental starting of the
pump!
Fault Cause
• Supply failure;
Motor does not start.
Fuses blow or motor
short-circuit; earth-
starter trips out im-
leakage; fault in
mediately. Caution:
cable or motor
Do not start again!
winding
• Fuses blow due to
use of wrong type
of fuse
• Impeller blocked by
impurities
• Level switch out of
adjustment or de-
fective
• Low setting of
Pump operates, but
motor starter trips
thermal relay in mo-
out after a short
tor starter
while
• Increased current
consumption due to
large voltage drop
• Impeller blocked by
impurities. In-
creased current
consumption in all
three phases
• Impeller blocked by
Pump operates at
below-standard
impurities
• Wrong direction of
performance and
power consumption
rotation (only 3 Ph-
pumps)
• Discharge valve
Pump operates, but
gives no liquid
closed or blocked
• Non-return valve
blocked
• Air in pump
Remedy
• Have the cable
and motor
checked and re-
paired by a quali-
fied electrician
• Install fuses of
the correct type
• Clean the
impeller
• Check the level
switch
• Set the relay in
accordance with
the specifications
on the pump label
• Measure the volt-
age between two
motor phases.
Tolerance: ± 10%
(± 5% for explo-
sion-proof
pumps)
• Clean the
impeller
• Clean the
impeller
• Check the direc-
tion of rotation
and possibly in-
terchange two
phases (see sec-
tion 6.4)
• Check the dis-
charge valve and
possibly open
and/or clean
• Clean non-return
valve
• Vent the pump
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