10
7.2. Automatic Float Switch Control
Pumps supplied with a float switch start and stop automati-
cally according to the liquid level in the pit automatically.
Both the distance between start level (on) and stop level (off)
of the pump and the level of the fixing point of the float
switch can be adjusted.
The start level must be below the bottom of the liquid inlet
pipe of the pit to prevent backflush into the pipe. The stop
level must be above the water inlet of the pump to prevent
an air cushion in the pump.
To adjust the start and stop level simultaniously, the float
switch slide must be moved along the motor housing strip.
Note: Only the proper adjustment and fixing of the float
switch cable will guarantee a reliable pump operation. After
any modification of the float switch adjustment the function
must be checked by a test-run of the pump.
Pay attention to the maximum depth of immersion (see
pump label).
If the pump is installed in a sump, the sump opening
must be covered with a tread-safe cover after installation.
The operator has to prevent damage through the flood-
ing of rooms caused by defects of the pump through the use
of appropriate measures (e.g. installation of alarm units,
backup pump or like that).
8. Start-Up
Connect the pump with the mains supply. Models without
float switch start running irrespective of the liquid level. Mod-
els with float switch operate according to the liquid level
automatically. The pump starts running if the float switch
reachs the adjusted start level and stops running if the float
switch reachs the adjusted stop level.
Never let the pump run dry for a long time of period, as it
will destroy the pump (danger of overheating).
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 authorized work-
shop. 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 prod-
uct 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 prod-
uct 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 rotating
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 continuously, the
pump should be inspected every 1.000 operating 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 operation
(turn the shaft by hand). Replace defective ball bearings. 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 (available
on request). Used oil is to be disposed accordingly.
Servicing Contract
For a regular expert execution of all necessary maintenance
and inspection we recommend the conclusion of a servicing
contract by our HOMA Service. Please contact our HOMA
customer service.
