System Maintenance - Daikin EWWQ-AJYNN Service Manual

Maintenance
1.4

System Maintenance

1
General
Compressor
maintenance
3
Electrical control
centre
5 5
Refrigerant
sight-glass
5–6
To ensure proper operation at peak capacity and to avoid damage to package components, a program
of periodic inspections should be set up and followed. The following items are intended as a guide and
are to be used during inspection and must be combined with sound coming from compressor and
electrical practices to ensure troublefree performance. The liquid line sightglass indicator on all circuits
must be checked to be sure the glass is full and clear. If the indicator shows that a wet condition exists
and/or there are bubbles in the glass, even with a full refrigerant charge, the filter-drier element must
be changed.
The screw Frame 4 compressor does not require frequent maintenance. However, vibration test is an
excellent check for proper mechanical operation. Compressor vibration is an indicator of the
requirement for maintenance and contributes to a decrease in unit performance and efficiency. It is
recommended to check the compressor with a vibration analyser at or shortly after start-up and again
on an annual basis. When performing the test the load should be maintained as closely as possible to
the load of the original test. The vibration analyser test provides a fingerprint of the compressor and
when performed routinely it can give a warning of impending problems.
The compressor is supplied with a cartridge oil filter. It is a good policy to replace this filter anytime the
compressor is opened for servicing.
Warning: Electric shock hazard. Turn off all electrical power supplies before continuing with following
service.
Caution: It is necessary to de-energise the complete electrical panel, including crankcase heater,
before doing any servicing inside.
Prior to attempting any service on the control centre it is advisable to study the wiring diagram so that
you understand the operation system of the water chiller. Electrical components do not require
particular maintenance other than a monthly tightening of cables.
Warning: The warranty becomes void if the wiring connection to the unit is not in accordance with the
specification. A blown fuse or tripped protector indicates a short ground or overload. Before replacing
the fuse or restarting the compressor, the problem must be found and corrected. It is important to have
a qualified electrician to service this panel. Unqualified tampering with the controls can cause serious
damage to equipment and void the warranty.
The refrigerant sight-glasses should be observed periodically (a weekly observation should be
adequate). A clear liquid sight-glass indicates the right refrigerant charge in the system to insure
proper feed through the expansion valve. Bubbling refrigerant in the sight-glass, during stable run
conditions, indicates that the system may be short of refrigerant charge. Refrigerant gas flashing in the
sight-glass could also indicate an excessive pressure drop in the liquid line, possibly due to a clogged
filter-drier or a restriction elsewhere in the liquid line. If sub-cooling is low add charge to clear the
sight-glass. If sub-cooling is normal and flashing is visible in the sight-glass check the pressure drop
across the filter-drier. An element inside the sight-glass indicates the moisture condition corresponding
to a given element colour. If the sight-glass does not indicate a dry condition after about 3 hours of
operation, the unit should be pumped down and the filter-driers changed.
The following table is a guide to determinate the dry or wet condition of the system:
COLOUR
Green (Sky Blue)
Yellow (Pink)
ESIE07-05
MEANS
Dry
Wet
Part 5 – Maintenance