Lennox International Inc 2SCU13 Start-Up, Refrigerant Charge Adjustment, Refrigerant Charging

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START-UP

CAUTION

If unit is equipped with a crankcase heater, it should be energized 24 hours before unit start-up to prevent compressor damage as a result of slugging.

1.Rotate fan to check for frozen bearings or binding.

2.Inspect all factory and field-installed wiring for loose connections.

3.After evacuation is complete, open liquid line and suction line service valves to release refrigerant charge (contained in outdoor unit) into system.

4.Replace the stem caps and secure finger tight, then tighten an additional 1/6 of a turn.

5.Check voltage supply at the disconnect switch. The voltage must be within the range listed on the unit nameplate. If not, do not start equipment until the power company has been consulted and the voltage condition corrected.

6.Set thermostat for cooling demand, turn on power to indoor blower and close the outdoor unit disconnect switch to start the unit.

7.Recheck unit voltage with unit running. Power must be within range shown on unit nameplate.

Refrigerant Charging

Units are factory charged with the amount of HCFC-22 refrigerant indicated on the unit rating plate. This charge is based on a matching indoor coil and outdoor coil with 15' line set. For varying lengths of line set, refer to Table 5 for refrigerant charge adjustment.

Refrigerant Charge Adjustment

Liquid Line Set

Oz. per 5 ft. adjust

Diameter

from 15 ft. line set*

 

 

3/8 in.

3 oz. per 5 ft.

 

 

*If line length is greater than 15 ft., add this amount. If line length is less than 15 ft., remove this amount.

Table 5

If the system is void of refrigerant, clean the system using the procedure described below.

1.Use dry nitrogen to pressurize the system and check for leaks. Repair leaks, if possible.

2.Evacuate the system to remove as much of the moisture as possible.

3.Use dry nitrogen to break the vacuum.

4.Evacuate the system again.

5.Weigh the appropriate amount of HCFC-22 refrigerant (listed on unit nameplate) into the system.

6.Monitor the system to determine the amount of moisture remaining in the oil. Use a test kit to verify that the moisture content is within the kit’s dry color range. It may be necessary to replace the filter drier several times to achieve the required dryness level. If system dryness is not verified, the compressor will fail in the future.

The outdoor unit should be charged during warm weather. However, applications arise in which charging must occur in the colder months. The method of charging is deter- mined by the unit’s refrigerant metering device and the outdoor ambient temperature.

Measure the liquid line temperature and the outdoor ambient temperature as outlined below:

1.Connect the manifold gauge set to the service valve ports as follows:

•Low pressure gauge to suction line service valve

•High pressure gauge to liquid line service valve

2.Close manifold gauge set valves. Connect the center manifold hose to an upright cylinder of HCFC-22.

3.If room temperature is below 70°F, set the room thermo- stat to call for heat. This will create the necessary load for properly charging the system in the cooling cycle.

4.Use a digital thermometer to record the outdoor ambient temperature.

5.When the heating demand has been satisfied, switch the thermostat to cooling mode with a set point of 68°F. When pressures have stabilized, use a digital thermometer to record the liquid and suction line temperatures.

6.The outdoor temperature will determine which charg- ing method to use. Proceed with the appropriate charging method.

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Contents Installation and Maintenance Instructions Table of ContentsTorque Table InstallationInstallation Clearances Slab MountingWind Barrier Construction Electrical WiringSlab Mounting Thermostat DesignationsBrazing Connection Procedure Outside Unit Placement InstallationInstalling Refrigerant Line Refrigerant Line Set DiametersRefrigerant Line Sets Installing Horizontal Runs Refrigerant Line Sets Transition from Vertical to HorizontalFixed Orifice Systems Refrigerant Metering DeviceExpansion Valve Systems To Open Liquid or Suction Line Service Valve Metering Device InstallationTo Access the Schrader Port Fixed Orifice DataSuction Line Ball Type Service Valve Ball Type Service Valve Valve OpenTo Close Liquid or Suction Line Service Valve Leak TestingEvacuation START-UP Refrigerant Charge AdjustmentRefrigerant Charging Subcooling Values for Fixed Orifice or TXV Systems Charge Using Weigh-In Method Fixed Orifice/TXV SystemsOutdoor Liquid Subcooling ±1F Temp Outdoor Ambient Temp Superheat Check Charge Using Normal Operating PressuresApproach Values for TXV Systems ModelNormal Operating Pressures Fixed Orifice RFCIndoor Coil MaintenanceOperation Indoor UnitStart-Up and Performance Checklist Single Phase Wiring Diagram P/N Three Phase Wiring Diagram P/N Limited Warranty

2SCU13 specifications

Lennox International Inc. is renowned for its innovation in heating, ventilation, air conditioning, and refrigeration (HVACR) systems. One of its standout products is the 2SCU13 model, which embodies the company's commitment to energy efficiency and customer comfort. This air conditioning unit is particularly appreciated in both residential and light commercial applications for its robust performance and advanced features.

The 2SCU13 is designed with a focus on energy efficiency, boasting a SEER rating of up to 14. This not only eases the burden on utility bills but also aligns with environmentally conscious practices by reducing carbon footprints. The unit’s efficiency is further enhanced by its scroll compressor, which is known for reliable performance and quiet operation.

One of the key characteristics of the 2SCU13 is its two-stage cooling system. This technology allows the unit to operate at two different cooling capacities, adapting to varying temperature conditions. By running at a lower capacity during mild weather, the 2SCU13 minimizes energy consumption, while still ensuring optimal comfort during hotter days by ramping up to full capacity when needed. This adaptability also contributes to a more consistent temperature throughout the space being cooled.

Another notable feature is the unit's humidity control capabilities. The two-stage operation also aids in managing indoor humidity levels, making it an excellent choice for areas with high humidity. Proper humidity control not only enhances comfort but also plays a crucial role in improving indoor air quality.

The design of the 2SCU13 ensures durability and longevity. It comes equipped with a rugged cabinet that withstands the elements, along with a baked-on powder coat finish that resists rust and corrosion. The unit also includes a protective grille that serves to shield the coil from debris, further enhancing its lifespan.

With easy installation and maintenance in mind, Lennox has incorporated service-friendly features into the design of the 2SCU13. The unit includes a convenient access panel that simplifies routine checks and repairs, making it easier for homeowners and technicians alike.

Overall, Lennox International Inc. 2SCU13 represents a harmonization of efficiency, comfort, and durability, making it a noteworthy choice among HVAC systems. Its advanced technology and design features ensure that it meets the evolving needs of consumers while providing reliable performance for years to come.
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