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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
within the limits permitted by the compressor and the
unit. 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 run-
ning 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. Ensure that the condensate drain pan of the
40ALZ unit is perfectly clean and does not contain
sludge or other foreign substances, corrosion, etc. and
is level.
Also verify the defrost water outlet in the 38 UQZ units.
•
Inlet 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 clean with
water and air. Straighten bent aluminium fins with a
suitable fin comb. Check for unusual compressor noise.
Check for correct operation of the 4-way or cycle
reversing valve.
•
Controls: Check the operation of all electric controls,
high and low pressurestats, thermostats, etc.
•
Fans: The fan of the 38UQZ unit must rotate freely.
There must not be any foreign elements in the fans of
the 40ALZ indoor units. Please check:
a)
the condition of the pulleys
b) the condition of the belts
c)
the belt tension.
Periodically check the condition of the belts and pulleys
and ensure that they are correctly aligned. Also ensure
that the belt tension is correct. At the first start-up,
and after a longer shut-down period, recheck the belt
tension after a few hours of operation.
6
Legend
1
Pulleys
2
Motor and fan shafts must be parallel
3
Straight-edge must be parallel with belt
•
Lubrication: Both the motors and the fans have
factory-lubricated and sealed bearings, and need no
further lubrication.
The compressor has its own oil supply, including the
amount for the siphons and refrigerant lines. Oil should
not be added unless a leak has occurred. Always use
oil of the same brand and type that was used for the
original charge.
Servicing recommendations
•
Before replacing any of the elements in the cooling
circuit, ensure that the entire refrigerant charge is
removed from both the high and low pressure sides of
the unit.
•
The control elements of the cooling system are highly
sensitive. If they need to be replaced, care should be
taken not to overheat them with blowlamps whilst
soldering. A damp cloth should be wrapped around
the component to be soldered, and the flame directed
away from the component body.
•
Silver alloy soldering rods should always be used.
•
If the total unit gas charge has to be replaced, the
quantity should correspond to the original unit gas
and liquid charge, plus the required charge for the
refrigerant lines. The unit should be properly evacuated
beforehand.
•
During unit operation all panels should be in place,
including the electrical box access panel.
•
If it is necessary to cut the lines of the refrigerant
circuit, tube cutters should always be used and never
tools which produce burrs. All refrigerant circuit tubing
should be of copper, specially made for refrigeration
purposes.
Fig. 31
2 kg or 3 kg
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