Lennox International Inc 15GCSX, Gas Packaged Units installation instructions Cooling Start−Up

Cooling Start−Up

The cooling section is a complete factory package utilizing an air−cooled condenser. The system is factory−charged with HFC−410A refrigerant. The compressor is hermetically sealed, internally sprung and base−mounted with rubber−insolated hold−down bolts.

Pre−Start Check List:

1 − Make sure refrigerant lines do not rub against the cabinet or each other.

2 − Inspect all electrical wiring, both factory− and field−installed, for loose connections.

3 − Check voltage at the disconnect switch. Voltage must be within the range listed on the unit nameplate. If not, consult power company and have voltage condition corrected before starting unit.

4 − Recheck voltage with unit running. If power is not within the range listed on the unit nameplate, stop the unit and consult the power company. Check unit amperage. Refer to unit nameplate for correct running amps.

5 − Make sure filter is in place before unit start−up.

Cooling Sequence of Operation

When the thermostat calls for cooling,

and 1). This completes the low voltage control

circuit, energizing the compressor, condenser fan motor and blower motor.

NOTE − At the start of the each cooling demand, the combustion air blower (draft motor) will operate for 10 seconds.

Unit compressors have internal protection. If there is an abnormal rise in the compressor temperature, the protector will open and the compressor will stop.

Blower Delay − Cooling

In the cooling mode, the circulating air blower operation is delayed for 5 seconds after the compressor starts. The blower continues to operate for 90 seconds after the compressor is de−energized.

NOTE − With the proper thermostat and subbase, continuous blower operation is possible by closing the R to G circuit. Cooling blower delay is also functional in this mode.

System Performance

This self−contained system has been factory−charged for optimal performance. If performance is questionable, use the following procedure to check the system.

Ensure that unit has been installed per these instructions and that line voltage and air flow are both correct. Check subcooling values by measuring pressure at the liquid line (high side) service port. Measure liquid line temperature within 2 inches of the service port connection to its main tube. If subcooling measured deviates from values in table 7 by more than 2 degrees F, check internal seals, service panels and duct system for air leaks, as well as restrictions. Also check blower speed settings. Make all necessary adjustments. If unit performance remains questionable, recover unit refrigerant charge, evacuate to 500 Microns, and weigh in refrigerant to match value given on unit nameplate. It is critical that exact required charge is used. Failure to follow this instruction will compromise system performance. If unit performance is still questionable, check for blocked coil or circuits, malfunctioning metering devices or other system component problems.

Table 7

Liquid Subcooling Values

	Liquid Line Subcooling
Unit Model No.	+/− 2 Deg. F @ ARI
	82_F OD minus 80_F IDDB
	/ 67_F IDWB
15GCSX−24	12_
15GCSX−30	12_
15GCSX−36	15_
15GCSX−42	10_
15GCSX−48	7_
15GCSX−60	8_

Verify system performance using table 8 as a general guide. Table 8 should not be used for charging unit. Minor variations in these pressures may be expected due to differences in installations. Significant differences could mean that the system is not properly charged or that a problem exists with some component in the system.

Used carefully, this table could serve as a useful service guide. Data is based on 80°F dry bulb / 67°F wet bulb return air. Allow unit operation to stabilize before taking pressure readings.

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