OPERATION
Sequence of Operation
Cooling
Upon cooling demand, the thermostat closes circuit R andY. Closing R and Y closes the unit contactor, starting the compressor and outdoor fan.The thermostat automatically closes R to G circuit which also brings on the indoor blower at the same time. Upon satisfying cooling demand, the thermo- stat will open the above circuits and open the main contactor, stopping the compressor and outdoor fan. If the unit is equipped with a delay timer, the blower will continue to operate for 90 seconds which improves system efficiency.
Circulating Air Blower
The circulating air blower is controlled by a timing circuit in the blower control.Timings are not adjustable.
There is no blower “on” delay after a call for heating or cooling. Blower “off” delay is 90 seconds after the thermo- stat is satisfied.
Cooling System Performance
For maximum performance of the cooling system, operat- ing temperatures and pressure should be checked. Super- heat should be determined at Standard ARI test conditions of 82°F outdoor and 80°F indoor dry bulb/67°F wet bulb. If superheat measured deviates from values found in Table 3, refrigerant charge should be adjusted accordingly for maximum performance.
Suction Superheat
| Suction Superheat | |
Size | @ ARI Conditions | |
82° OD - 80° IDDB/67° IDWB | ||
|
|
|
| R22 | 410A |
|
|
|
24 | 22° | 15° |
|
|
|
30 | 20° | 15° |
36 | 20° | 12° |
|
|
|
42 | 20° | 12° |
48, 60 | 20° | 10° |
|
|
|
Table 3
# 48392M005 | Page 7 |
