49
Maintenance
General
Qualified technicians must perform routine
service checks and maintenance. This
includes reading and recording the
condensing and suction pressures and
checking for normal sub-cooling and
superheat.
Compressors
The scroll compressors are fully hermetic and
require no maintenance except keeping the
shell clean.
Refrigerant Filter Driers
Each refrigerant circuit contains a filter drier.
Replace when there is excessive pressure
drop across the assembly or moisture is
indicated in a liquid line sight glass.
Table 20 - Max Filter Drier Pressure Drops
Oil Level
It is critical that the refrigerant line piping is
designed to maintain proper oil return to the
compressors. Some systems may require oil
to be added in addition to what is provided in
the compressors. The oil is a POE type and
is available from your AAON Representative
under part number R63681.
Proper oil level must be observed under
minimum load conditions. On units equipped
with tandem compressors, all oil is returned
to the lead compressor in each tandem pair.
When only the lead compressor is running,
the oil level must be a minimum of ⅜ from
the bottom of the sight glass. With both
compressors running, the level in the lead
compressor will drop to the bottom of the
sight glass and the level in the second
compressor must be a minimum of ⅜, from
the bottom of its sight glass. Do not allow the
oil level in the sight glass to exceed ¾ full
level.
To Next Page
Loading...
