14
8. Start-Up
Never let the pump run dry for a long time of period,
as it will destroy the pump (danger of overheating).
Start the pump, when the system has been filled with
liquid and vented. Open the isolating valves. Check the
position of the floatswitches. If necessary, check the di-
rection of rotation of the pump, as described under 6.5.
Put the switch on the control box to the required mode of
operation.
9. Maintenance and Repair
In case of a defect of the pump, a repair shall be
carried out only by the manufacturer or through an au-
thorized workshop. Modifications of the pump must be
confirmed by the manufacturer. Only HOMA spare parts
shall be used.
In accordance with the product liability law we point
out that we shall not be liable for damages caused by our
product due to unauthorized repair by persons other than
the manufacturer or an authorized workshop or due to the
use of spare parts other than original HOMA parts. The
same product liability limitations are valid for accessories.
Before maintenance or repair disconnect the pump
from the power supply to avoid accidental starting of the
pump!
Before maintenance or repair make sure that all rotat-
ing parts stand still!
Before carrying out maintenance and service, the
pump must be thoroughly flushed with clean water. Rinse
the pump parts in clean water after dismanteling.
At pump types with oil chamber an overpressure can
escape with loosening of the oil chamber control screw.
Screw only when pressure balance took place.
Pumps running under normal operation conditions should
be inspected at least once a year. If the pumped liquid is
very muddy or sandy or if the pump is operating continu-
ously, the pump should be inspected every 1.000 operat-
ing hours.
For long and trouble-free operation of the pump, following
points should be checked regularly:
- Nominal current (A): Check with amp-meter.
- Pump parts and impeller: Check for possible wear.
Replace defective parts.
- Ball bearings: Check the shaft for noisy or heavy opera-
tion (turn the shaft by hand). Replace defective ball bear-
ings. A general overhaul of the pump is usally required in
case of defective ball bearings or poor motor function.
This work must be carried out by an authorized
service workshop.
- Cable entry: Make sure that the cable entry is watertight
and that the cables are not bent sharply and/or pinched.
Additionally at pump types with oil chamber:
- Oil level and oil condition in oil chamber:
Put the pump in horizontal position, so that the screw of
the oil chamber is above (at larger pumps: one of both
screws). Remove the screw and infer a small quantity of
oil. The oil becomes greyish white like milk if it contains
water. This may be the result of defective shaft seal.
In this case leave the condition of the shaft seals by a
HOMA Service to examine.
The oil should be replaced after 3000 operating hours.
Oil type: Shell Tellus C22, degradable HOMA-Atox (avail-
able on request). Used oil is to be disposed accordingly.
Servicing Contract
For a regular expert execution of all necessary mainte-
nance and inspection we recommend the conclusion of a
servicing contract by our HOMA Service. Please contact
our HOMA customer service.
10. Fault Finding Chart
Before maintenance or repair disconnect the pump from
the power supply to avoid accidental starting of the pump!
Fault Cause
Remedy
Motor does not start.
Fuses blow or motor
starter trips out imme-
diately.
Caution:
Do not start
again!
•
Supply failure; short-
circuit; earth-
leakage fault in
cable or motor wind-
ing
•
Have the cable and
motor checked and
repaired by a quali-
fied electrician.
•
Fuses blow due to
use of wrong type of
fuse.
•
Install fuses of the
correct type.
•
Impeller blocked by
impurities.
•
Clean the impeller.
•
Level switch out of
adjustment or defec-
tive.
•
Check the level
switch.
Pump operates, but
motor starter trips out
after a short while.
•
Low setting of
thermal relay in
motor starter.
•
Set the relay in
accordance with
the specifications
on the pump label.
•
Increased current
consumption due to
large voltage drop.
•
Measure the
voltage between
two motor phases.
Tolerance: ±10%
(±5% for explosion-
proof pumps).
•
Impeller blocked by
impurities. Increased
current consumption
in all three phases.
•
Clean the impeller.
Pump operates at
below-standard per-
formance and power
consumption.
•
Impeller blocked by
impurities.
•
Clean the impeller.
•
Wrong direction of
rotation.
•
Check the direction
of rotation and
possibly inter-
change two phases
(see section 6.5).
Pump operates, but
gives no liquid.
•
Discharge valve
closed or blocked.
•
Check the dis-
charge valve and
open and/or clean.
•
Non-return valve
blocked
•
Clean the non-
return valve.
•
Air in pump.
•
Vent the pump.
Pump cycling between
start and stop.
•
Level switch out of
adjustment or de-
fective.
•
Check the level
switch.
