AAON CC-063 - Manual (Page 23)

23
Startup
(See back of the manual for startup form.)
Compressors
All
compressors are equipped with
crankcase heaters, which should be
energized at least 24 hours prior to cooling
operation of the compressor.
Charging
Refrigerant & Adjusting
Refrigerant Charge
Charging a system in the field must be based
on determination of liquid sub-cooling and
evaporator superheat. On a system with a
thermostatic expansion valve (TXV) liquid
sub-cooling is more representative of the
charge than evaporator superheat but both
measurements must be taken.
Before Charging
Unit being charged must be at or near full
load conditions before adjusting the charge.
Units equipped with hot gas bypass must
have the hot gas bypass valve closed to get
the proper charge.
Improper installation, adjustment,
alteration, service or maintenance
can
cause property damage,
personal injury or loss of life. Startup
and service must be performed by a
Factory Trained Service Technician.
WARNING
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
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.
CAUTION
Rotation must be checked on all
MOTORS AND COMPRESSORS of
three phase units. Condenser fan
motors should all be checked by a
qualified service technician at startup
and any wiring alteration should only
be
made at the unit power
connection.
CAUTION
Scroll compressors are directional
and will be damaged by operation in
the wrong direction. High pressure
switches on compressors have been
disconnected after factory testing.
Rotation should be checked by a
qualified service technician at startup
using suction and discharge pressure
gauges and any wiring alteration
should only be made at the unit
power connection.
CAUTION