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IMPORTANT
Mineral oils are not compatible with R-410A. If oil must
be added, it must be a polyolester oil.
NOTE: Both airflow and refrigerant charge must be
monitored for proper system set-up. It may be necessary to
alternately check and adjust the airflow and the refrigerant
charge.
If the system is void of refrigerant, or if the outdoor ambient
temperature is cool, use the weigh-in method to charge the
unit. Do this after any leaks have been repaired.
1.
Recover the refrigerant from the unit.
2.
Conduct a leak check, then evacuate as previously
outlined.
3.
Weigh in the charge according to the total amount
shown on the unit nameplate.
If weighing facilities are not available or if unit is being
charged during warm weather, use one of the following
procedures.
•
For systems using a TXV on the indoor evaporator
and outdoor temperature above 60°F – charge in
cooling mode using the subcooling method and table
provided on the unit access panel.
•
For systems below 60°F – charge in heating mode
using the subcooling method and table provided on
the unit access panel. Attach low pressure gauge
hose to auxiliary service port to access suction side in
heating mode.
NOTE: All unit table values are based on 70 to 80°F
indoor return air temperature for cooling mode, and
65°F to 75°F return air temperature for heat mode.
High Pressure Switch
This unit is equipped with a high pressure switch which
is located on the liquid line. The SPST, normally closed
pressure switch opens when liquid line pressure rises above
the factory setting of 590 +/- 15 psig and automatically
resets at 418 +/- 15 psig.
Torque Requirements
When servicing or repairing HVAC components, ensure
the fasteners are appropriately tightened. Table 11 shows
torque values for fasteners.
508311G01 / 31-5000754
Fastener
Valve Stems
Stem Caps
Service Port Caps
Sheet Metal Screws
#8 Machine Screws
#10 Machine Screws
Compressor Bolts
Liquid and Suction Line Service Valves
The liquid line and suction line service valves (see Figure
13) and service ports are used for leak testing, evacuation,
charging, and checking charge.
Each valve is equipped with a service port which has a
factory-installed Schrader valve. A service port cap protects
the Schrader valve from contamination and serves as the
primary leak seal.
Issue 2250
Torque
4 in. lbs.
8 ft. lbs.
8 ft. lbs.
16 in. lbs.
16 in. lbs.
28 in. lbs.
90 in. lbs.
Table 11. Torque Table
Figure 13.
Page 21 of 26
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