Automatic Float Switch Control; Start-Up; Maintenance And Repair - Homa TCM Series Installation And Operation Instruction Manual

⇒ Clean out debris from the pit before lowering the pump
into operation position.
⇒ Fit the coupling flange at the discharge of the pump.
Make sure that the rubber profile-seal is properly fixed to
the flange and will not fall off when the pump is lowered
into the pit. Slide the guide bar of the coupling flange
between the guide rails and lower the pump into the pit
by means of a chain secured to the pump handle. When
the pump reaches the auto-coupling base unit, it will
automatically connect tightly.
⇒ Hang up the end of the chain to a suitable hook at the
top of the pit.
⇒ Adjust the length of the motor cable, so that it is not
damaged during the pump operation. Make sure that the
cables are not sharply bent or pinched.

7.3 Automatic Float Switch Control

The pumps may be supplied with float switch level con-
trollers. They start and stop the pump according to the
liquid level in the pit.
The difference in level between start and stop must be
adjusted by adjusting the free swinging length of the ca-
ble between the float switch and the cable fastening.
Long cable end: Large difference in level.
Short cable end: Small difference in level.
The stop level must be adjusted in such a way, that the
pump stops before the liquid level is lowered below the
top of the pump volute.
The start level must in any case be below the bottom of
the liquid inlet pipe of the pit.
The high alarm level, if a separate float switch for that is
installed, should be adjusted approx. 10 cm above the
start level, in any case it must be below the bottom of the
liquid inlet pipe of the pit, so that the start level must be
adjusted accordingly.
Never place the float switch in the sump without fixing the
float switch cable to a fixed point i the sump, because the
float switch needs a rotation around the fixing point of the
cable to operate without any problems. Non-observance
may cause an overflow because the pump does not start
running or a dry run of the pump in fact that the pump
does not stop, which will destroy the pump.
Note: Only the proper adjustement and fixing of the float
switch cable will guarantee a reliable pump operation. Af-
ter any modification of the float switch adjustment the
function must be checked by a test-run of the pump.

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 float switches. If necessary, check the di-
rection of rotation of the pump, as described under 6.4.
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 car-
ried out only by the manufacturer or through an author-
ized workshop. Modifications of the pump must be con-
firmed 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.
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