Product data

REFRIGERANT CHARGING:
WARNING:
To prevent personal injury, wear safety glasses and gloves when handling refrigerant. Do not
overcharge system compressor flooding can result.
WARNING:
Service valves must be fully back seated to close service port. There is no Schrader valve at the
service port, and failure to backseat the valve could result in loss of system charge or personal injury.
NOTE:
Do not vent or depressurize unit refrigerant to atmosphere. Remove and recover refrigerant following
accepted practices.
Superheat Method —Cooling, Non-TXV (Thermostatic Expansion Valve)
To check and adjust charge during cooling season, use Tables 3 and 4 and the following procedure:
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure vapor line pressure by attaching a gage to vapor valve service port.
3. Measure vapor line temperature by attaching a service thermometer to unit vapor line near vapor line valve.
Insulate thermometer for accurate readings.
4. Measure outdoor coil inlet-air dry bulb temperature with a second thermometer.
5. Measure indoor coil inlet-air wet bulb temperature with a sling psychrometer.
6. Refer to Table 3. Find air temperature entering out-door coil and wet-bulb temperature entering indoor coil.
Note the superheat temperature at this intersection.
7. Refer to Table 4. Find superheat temperature and vapor line pressure and note vapor line temperature.
8. If unit has higher vapor line temperature than charted temperature, add refrigerant until charted temperature is
reached.
9. If unit has lower vapor line temperature than charted temperature, remove and recover refrigerant until charted
temperature is reached.
10. If air temperature entering outdoor coil or pressure at vapor line valve changes, charge to new vapor line
temperature indicated on chart.
11. This procedure is independent of indoor-air quantity.
Subcooling Method — Cooling, TXV (Thermostatic Expansion Valve)
To check and adjust charge during cooling season, use Table 5 and the following procedure:
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure liquid line temperature near liquid line service valve, and measure liquid pressure at liquid line service
valve. Use a digital thermometer for all temperature measurements. DO NOT use mercury or dial-type
thermometers.
3. Refer to Table 5. Find measured liquid pressure and read the liquid line temperature at the required subcooling
temperature.
4. If the measured liquid line temperature does not agree with the required liquid line temperature, ADD
refrigerant to lower the temperature, or REMOVE refrigerant to raise the temperature (allow a tolerance of ±3 °F)
HEATING MODE (Heat Pump Models)
To check system operation during heating cycle, use Table 6. This table indicates whether a correct relationship
exists between system operating pressure and air temperatures entering indoor and outdoor units. In heating mode,
check should be made approximately 15 minutes after defrost with unit running with a clean coil. If pressure and
temperature do not match on chart, system refrigerant charge may not be correct or other system abnormalities may
exist. Do not use table to adjust refrigerant charge. When recharging is necessary during heating season, weigh in
total charge as indicated in separate indoor unit installation instructions. Remove any refrigerant remaining in the
system before recharging. If the system has lost complete charge, evacuate and recharge by weight. Service port
connections are provided on liquid and vapor line service valves. For evacuation and recharging, Dial-a-Charge
charging cylinder, or similar device, is an accurate device for recharging systems by weight.