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11 - STANDARD MAINTENANCE
11.8 - Compressor maintenance
11.8.1 - Oil separator
Check the correct operation of the heaters and check that they
are well attached to the oil separator ring.
11.8.2 -
Integral oil filter change
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 bearing 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 filter service port and the oil pressure
port. 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.
11.8.3 - 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.
The reverse rotation protection scheme must be able to determine
the direction of rotation and stop the compressor within 300 ms.
Reverse rotation is most likely to occur when-ever the wiring to
the compressor terminals is disturbed.
To minimize the opportunity for reverse rotation, the follow-ing
procedure must be applied. Rewire the power cables to the
compressor terminal pin 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.
The switch that has been selected for detecting reverse rotation
is Carrier part number HK01CB001. This switch opens the contacts
when the pressure falls below 7 kPa. The switch is a manual reset
type that can be reset after the pressure has once again risen
above 70 kPa. It is critical that the switch be a manual reset type
to preclude the compressor from short cycling in the reverse
direction.
11.9 -
Precaution for compressor power supply
bus bar connection
During re-connection it is imperative to:
-
engage each bus bar in the cage up to the stop
-
ensure visually that the bus bars have good contact at the
connection areas: there must not be any free move-ment
between the bus bar and the connection area created by the
fixing rivet of the contact block.
Connection of the contactor or current transformer
1
2
2
1 Power supply bus bar with riveted contact block
2 Contactor or current transformer connection zone
11.10 -
Check of power factor correction
capacitors
The verification consists in measuring input current of each
capacitor block. Absence of current despite capacitor is energized
is an indication that there is a defect.
Confirmation shall be done by removing the capacitors and
checking the underside.
Defect
Good
Summary of Contents for Aquaforce 30XAS Series
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