Unit installation

48 ACZ 010A through 039A IOMM ACZ1-2
Service
DANGER
Disconnect and tag-out all sources of power to the unit before doing any
service inside the unit. Failure to do so can cause serious personal injury or
death.
CAUTION
Service on this equipment must be performed only by trained, experienced,
qualified service personnel with special regard to regulations concerning
release of refrigerant to the atmosphere.
Note: Repeated tripping of equipment protection controls must be investigated and
corrected.
Thermostatic Expansion Valve
The field-installed expansion valve is responsible for allowing the proper amount of
refrigerant to enter the evaporator regardless of cooling load. It does this by maintaining a
constant superheat. (Superheat is the difference between refrigerant temperature as it
leaves the evaporator and the saturation temperature corresponding to the evaporator
pressure.) Typically, superheat should run in the range of 8°F to 12°F (4.4°C to 6.6°C).
Maintaining correct superheat to the compressor is an important element in extending
compressor life.
Filter-Driers
In general, the pressure drop across the field-installed filter-drier should be in the 6 to 10
psi range. It should be monitored and changed when the pressure drop reaches 10 psi.
After changing the filter-drier, check for leaks before recharging and returning unit to
operation.
Liquid Line Solenoid
The field installed liquid line solenoid valve does not normally require any maintenance.
Reliable operation of the solinoid valve is necessary for the pump-down function of the
unit's control system.