IOM 1207-6 • TRAILBLAZER
®
MODEL AGZ CHILLERS
130 www.DaikinApplied.com
Unit Maintenance
Unit Maintenance
General
On initial start-up and periodically during operation, it will
be necessary to perform certain routine service checks.
Among these are checking the liquid line sight glasses, taking
condensing and suction pressure readings, and checking
to see that the unit has normal superheat and subcooling
readings. A recommended maintenance schedule is located at
the end of this section.
Compressor
The scroll compressors are fully hermetic and require standard
maintenance practices:
• Check oil level monthly
• Inspect electrical connections annually
• Test oil annually
Crankcase Heaters
The scroll compressors are equipped with externally mounted
band heaters located at the oil sump level. The function of
the heater is to keep the temperature in the crankcase high
enough to prevent refrigerant from migrating to the crankcase
and condensing in the oil during off-cycle.
Power must be supplied to the heaters 8 hours before starting
the compressors.
Lubrication
No routine lubrication is required on AGZ units. The fan motor
bearings are permanently lubricated and no further lubrication
is required. Excessive fan motor bearing noise is an indication
of a potential bearing failure.
POE type oil is used for compressor lubrication. Further details
are listed in the Unit Service section on
WARNING
POE oil must be handled carefully using proper protective
equipment (gloves, eye protection, etc.) The oil must not
come in contact with certain polymers (e.g. PVC), as it may
absorb moisture from this material. Also, do not use oil or
refrigerant additives in the system.
WARNING
Polyolester Oil, commonly known as POE oil is a synthetic
oil used in many refrigeration systems, and is present in this
Daikin product. POE oil, if ever in contact with PVC/CPVC, will
coat the inside wall of PVC/CPVC pipe causing environmental
stress fractures. Although there is no PVC/CPVC piping in
this product, please keep this in mind when selecting piping
materials for your application, as system failure and property
damage could result. Refer to the pipe manufacturer’s
recommendations to determine suitable applications of the
pipe.
All-Aluminum Condenser Coils
The condenser coils are an all-aluminum design including the
connections, microchannels, fins (an oven brazing process
brazes the fins to the microchannel flat tube), and headers
(see
“Microchannel Coil Cross Section”)
, which eliminates
the possibility of corrosion normally found between dissimilar
metals of standard coils.
During the condensing process, refrigerant in the coil passes
through the microchannel flat tubes, resulting in higher
efficiency heat transfer from the refrigerant to the airstream. In
the unlikely occurrence of a coil leak, contact Daikin Applied to
receive a replacement coil module.
Figure 105: Microchannel Coil Cross Section
Cleaning Microchannel Aluminum Coils
Maintenance consists primarily of the routine removal of dirt
and debris from the outside surface of the fins.
Cleaning Epoxy Coated Coils
The following cleaning procedures are recommended as part
of the routine maintenance activities for epoxy coated coils.
Documented routine cleaning of epoxy coated coils is required
to maintain warranty coverage.
WARNING
Prior to cleaning the unit, turn off and lock out the main
power switch to the unit and open all access panels.
Remove Surface Loaded Fibers
Surface loaded fibers or dirt should be removed prior to water
rinse to prevent further restriction of airflow. If unable to back
wash the side of the coil opposite that of the coils entering air
side, then surface loaded fibers or dirt should be removed with
a vacuum cleaner. If a vacuum cleaner is not available, a soft
non-metallic bristle brush may be used. In either case, the tool
should be applied in the direction of the fins. Coil surfaces can
