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WA900-3EO
COMPONENT MAINTENANCE
1. REPLENISHING REFRIGERANT
“Flashing” in the liquid line sight glass of a previously charged
system indicates an inadequate charge of refrigerant and
replenishment is accomplished with the plant running.
Before replenishing a thorough leak test with a halogen leak detector
is required so that the offending leak can be located and rectified.
To replenish proceed as follows:-
1. Loosely connect the charging line from the cylinder of refrigerant
to the suction service valve situated on the compressor. Purge
the charging line.
2. Ensure that the charging line connection to the cylinder is fully
secure and that the cylinder is vertical.
3. Tighten the charging valve/charging line connection.
4. Open the charging valve slowly.
5. Add refrigerant until a steady liquid flow in the sight glass indi -
cates a fully charged condition. This can be accomplished by
adding a small mount of refrigerant at a time.
CAUTION: Particular care should be taken when
adding refrigerant as an overcharge of refrigerant
causes excessive head pressures which in turn can
cause considerable damage.
6. Backseat the suction service valve, but do not disconnect the
cylinder at this stage.
7. Allow running conditions to stabilise and check the sight glass
and discharge pressure. Add more refrigerant should flashing
occur.
8. On completion of the replenishment, tightly backseat the suction
service valve and remove the charging line. Fit a sealing cap to
the line before storing.
2. COILS
“Flashing” in the liquid line sight glass of a previously charged
system indicates an inadequate charge of refrigerant and
replenishment is accomplished with the plant running.
If cleaning is required wash with low pressure, mains temperature
water in the reverse direction to the air flow. For evaporator coil
ensure a baffle is used to prevent any water from entering cabin
through the return air plenum.
WARNING: DO NOT brush coil fins with a wire brush as
irreparable damage may occur. If fins are bent, use only
the correct fin comb to straighten them.
3. FAN MOTORS
Check the motors for excessive shaft end-play. Brushes are
accessible by removing the two plastic brush caps on each motor.
Note: Before removing brush caps thoroughly clean the
motors using water-free compressed air.
OPERATING INSTRUCTIONS