34
SERVICE
Indoor fan air adjustment
The drive is factory set in accordance with the tables on pages
18-25. When indoor pressure and air flow requirements differ
from nominal ratings, the motor pulley can be adjusted for
different available static pressure values.
To change the fan speed (see Fig. 28):
1.
Move the motor along its track in order to remove the
belt.
2.
Loosen the pulley setscrews and rotate as necessary.
3.
Tighten the setscrews .
4.
Replace the belt(s) in the channel of the pulley.
5.
Tighten the belt(s), using the tension screw nut and
washer .
To align fan and motor pulleys:
1.
Loosen fan pulley setscrews. Slide fan pulley along the
pulley shaft and align with the motor using a ruler,
making sure that it is parallel to the belt.
2.
Tighten the fan pulley setscrews.
To adjust the belt tension, loosen the motor mounting plate
bolts and slide the motor mounting plate until the belt is as
shown in Fig. 29.
Fig. 28 - Fan speed adjustment
Legend
1
Motor support
2
Motor pulley
3
Setscrews
4
Motor
5
Belt
6
Tensioning screw
7
Fan pulley
8
Fan scroll
GENERAL MAINTENANCE
ATTENTION: Before starting any servicing or maintenance
operation on the unit, make sure that the power supply has been
disconnected. A current discharge could cause personal injury.
In order to obtain maximum performance from the unit special
attention should be paid to the following points:
-
Electrical connections:
The supply voltage should be
±
10% of the nominal voltage limits.
Ensure that no faulty contacts exist in the terminal blocks,
contactor boards, etc. Make sure that all the electrical
connections are properly tightened, and that all the
electrical components (contactors, relays, etc) are firmly
secured to the corresponding rails.
Pay special attention to the condition of the connecting
cables between the control elements and the electrical box,
and to that of the unit power supply cable. They should
not be twisted and there should be no slits or notches in
the insulation. Check the starting and running consumptions
are within the limits specified in the corresponding
technical information.
-
Drainage:
Frequently check that the drain is not
obstructed, and that the condensate pan is clean and level.
-
Inlet air filter:
This should be cleaned periodically. The
frequency depends on the purity of the entering air. The
filter may be cleaned with a household vacuum cleaner, or
by immersing it in water.
-
Refrigerant circuit:
Ensure that there is no leakage of
refrigerant or oil from the compressor. Check that the high
and low side operating pressures are normal. Make sure
that the coils are not dirty. If necessary an optional filter
may be placed at the outdoor air inlet. Check for unusual
compressor noise.
-
Controls:
Check the operation of all electric controls,
high and low pressurestats, etc.