18
SERVICING & 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 subcooling and superheat.
Air cooled and evaporative condenser units require dif-
ferent maintenance schedules/procedures. Unit specific
instructions for both types are included in this manual.
COMPRESSORS
The scroll compressors are fully hermetic and require no
maintenance except keeping the shell clean.
REFRIGERANT FILTER DRIERS
Each refrigerant circuit contains a replaceable core filter
drier. Replacement is recommended when there is exces-
sive pressure drop across the assembly or moisture is
indicated in a liquid line sight glass.
▲
! IMPORTANT
The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFC's and HCFC's) as of
July 1, 1992. Approved methods of recovery,
recycling or reclaiming must be followed.
Fines and/or incarceration may be levied for
non-compliance.
The filter driers are provided with pressure taps and
shutoff valves for isolation when changing the core. For
safety purposes a service manifold must be attached
prior to filter maintenance.
CIRCUIT LOADING
100%
10 psig
MAX. PRESSURE DROP
50%
5 psig
REFRIGERANT CHARGE
All AAON 'RL' units are fully charged at the factory with
the refrigerant listed on the rating plate.
If additional refrigerant charging should become neces-
sary the it should be done at constant load condition.
Depending on the outdoor temperature, the refrigerant
liquid subcooling should fall between 6 and 20
0
F.
Subcooling temperatures will be higher if the load ex-
ceeds 75%.
TYPICAL SCROLL COMPRESSOR
COMPARTMENT
▲
!
WARNING
Prior to filter core service, a service manifold
MUST BE attached to in and out pressure
connections to assure no pressure exist during
filter maintenance. Non-compliance could
result in injury or violation of EPA regulations
▲
Refigerant overcharging leads to excess
refrigerant in condenser coils resulting in
elevated compressor discharge pressure.
DO NOT OVERCHARGE !
!
CAUTION
REPLACEABLE CORE FILTER / DRIER
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