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11.6 - Evaporator and condenser maintenance

Check that:
•

the insulating foam is intact and securely in place,

•

the sensors and flow switch are correctly operating
and correctly positioned in their support,

•

the water-side connections are clean and show no sign

of leakage.

11.7 - Compressor maintenance

11.7.1 - Oil filter change schedule

As system cleanliness is critical to reliable system operation,
there is a filter in the oil line at the oil separator outlet. The
oil filter is specified to provide a high level of filtration (5 µm)

required for long compressor life.

The filter should be checked after the first 500 hours of
operation, and every subsequent 2000 hours. The filter should

be replaced at any time when the pressure differential

across the filter exceeds 2 bar.

The pressure drop across the filter can be determined by

measuring the pressure at the discharge port (at the oil
separator) and the oil pressure port (at the compressor).
The difference in these two pressures will be the pressure

drop across the filter, check valve, and solenoid valve. The

pressure drop across the check valve and solenoid valve is

approximately 0.4 bar, which should be subtracted from the
two oil pressure measurements to give the oil filter pressure

drop.

11.7.2 - Compressor rotation control

Correct compressor rotation is one of the most critical appli-

cation considerations. Reverse rotation, even for a very
short duration, damages the compressor and can even

destroy it.

The reverse rotation protection scheme must be capable of
determining the direction of rotation and stopping the
compressor within one second. Reverse rotation is most
likely to occur whenever the wiring at the compressor

terminals has been modified.

To minimise the opportunity for reverse rotation, the follow-

ing procedure must be applied. Rewire the power cables to
the compressor terminals and/or the downstream variator
connection decks as originally wired.

For replacement of the compressor, a low pressure switch

is included with the compressor. This low pressure switch
should be temporarily installed as a hard safety on the high
pressure part of the compressor. The purpose of this switch
is to protect the compressor against any wiring errors at
the compressor terminal pin. The electrical contact of the
switch would be wired in series with the high pressure switch.
The switch will remain in place until the compressor has

been started and direction of rotation has been verified; at
this point, the switch will be removed.

11.4.2 - Connection precautions for the compressor power
terminals

These precautions must be applied during an intervention
that requires the removal of the power conductors connected
to the compressor supply terminals.

The tightening nut of terminal (6) supporting the isolator

(7) must never be loosened, as ist ensures terminal tightness

and compressor leak tightness.

The tightening of phase lug (4) must apply the torque

between counter nut (5) and tightening nut (3): during this

operation a counter-torque must be applied at counter nut
(5). Counter-nut (5) must not be in contact with the tightening
nut of terminal (6).

1. Torque application to tighten the lug

2. Avoid contact between the two nuts

3. Lug tightening nut

4. Flat lug

5. Counter-nut

6. Terminal tightening nut