LENNOX EL072XCSS Heat Pump Air Conditioner Instruction Manual

LENNOX EL072XCSS Heat Pump Air Conditioner Instruction Manual

⚠ WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional HVAC installer or equivalent, or service agency.

⚠ IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for noncompliance.

⚠ CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.

⚠ WARNING
To prevent serious injury or death:

1. Lock-out/tag-out before performing maintenance.
2. If system power is required (e.g., smoke detector maintenance), disable power to blower, remove fan belt where applicable, and ensure all controllers and thermostats are set to the “OFF” position before performing maintenance.
3. Always keep hands, hair, clothing, jewelry, tools, etc. away from moving parts.

Refrigerant Charge
NOTE – This extended HFC-410A charging procedure applies to non-matched Indoor and Outdoor units only. For matched Indoor and Outdoor units with same full load capacity, see unit instructions for charging procedure.
The ELITE units have a factory holding charge of 2 pounds of HFC-410A in each circuit. 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 determined by the outdoor ambient temperature. Before charging the unit, determine the liquid line temperature and the outdoor ambient temperature.

Charge Using the Subcooling Method ­ Outdoor Temperature > 65ºF (18.3ºC)

1. Attach pressure gauge set to liquid and suction service valves. Operate unit for at least five (5) minutes to allow system pressures to stabilize, then, use a thermometer to record the liquid line temperature.
2. At the same time, record the liquid line pressure reading.
3. Use a temperature/pressure chart for HFC-410A to determine the saturation temperature for the liquid line pressure reading.
4. Subtract the liquid line temperature from the saturation temperature (according to the chart) to determine subcooling (Saturation temperature Liquid line temperature = Subcooling Value).
5. Compare the subcooling value with those in table for the specific system match. If subcooling is greater than shown, recover some refrigerant. If subcooling is less than shown, add refrigerant.
6. Repeat steps 1 ­ 5 anytime refrigerant is added or recovered.
7. For Heat Pump models ­ Switch to heating mode and let the system stabilize at least 10 minutes. Then confirm that the pressures obtained from the connected gauges match the normal operating pressures (heating mode) in table for the specific system match.

Charge Using Normal Operating Pressures/Approach Method (High Capacity)
Outdoor Temperature 65ºF (18.3ºC) For best results, indoor temperature should be 70°F (21°C) to 80°F (26°C). Monitor system pressures while charging.

1. Attach pressure gauge set to liquid and suction service valves.
2. Operate unit for at least five (5) minutes to allow system pressures to stabilize. Record pressures.
3. Compare stabilized pressures with those provided in table for the specific system match. Minor variations are to be expected; significant differences could mean that the system is not properly charged or that a problem exists with some component in the system. The approach method is not valid for grossly over or under-charged systems.
4. Pressures higher than those listed indicate that the system is overcharged. Pressures lower than those listed indicate that the system is undercharged. Add or recover charge until the pressures are within the tolerances on the table.
5. Repeat steps 2 ­ 4 each time refrigerant is added or recovered.
6. Verify charge using the approach method.
7. Use the same thermometer to measure and record liquid line temperature.
8. Subtract the outdoor temperature from the liquid line temperature to determine the approach value (Liquid line temperature ­ Ambient temperature = Approach Temperature).
9. The approach temperature should match value given in table for the specific system match. If the values don’t agree with the those in table, add refrigerant to lower the approach temperature or recover refrigerant from the system to increase the approach temperature.
10. Operate unit for at least five (5) minutes to allow system pressures to stabilize.
11. Repeat steps 7 ­ 10 each time refrigerant is added or recovered.
12. For Heat Pump models ­ Switch to heating mode and let the system stabilize at least 10 minutes. Then confirm that the pressures obtained from the connected gauges match the normal operating pressures (heating mode) in table for the specific system match.

Outdoor Temperature < 65ºF (18.3ºC)
When the outdoor ambient temperature is below 65ºF (18.3ºC) it may be necessary to restrict the air flow through the outdoor coil to achieve pressures in the 325-375 psig (2240-2485 kPa) range. These higher pressures are necessary for checking the charge. Block equal sections of air intake panels and move obstructions sideways until the liquid pressure is in the 325-375 psig (2240-2485 kPa) range. See figure 1. Once pressure is in range, charge using Normal Operating Pressures/Approach Method (High Capacity).

Using the Normal Operating Pressures and Temperatures Table Tables may be used to help perform maintenance checks. This table is not a procedure for charging the system and any minor variations in the pressures may be expected due to differences in installations. However, significant deviations could mean that the system is not properly charged or that a problem exists with some component in the system.

Commercial Cooling Model(s) ­ Normal Operating Pressures and Temperatures

Note – Pressures at 80°F dry bulb and 67°F wet bulb entering indoor air temperatures.

EL072XCSS – EL090XASD

EL090XCSS – EL120XASD

(2) EL090XCSS – EL180XASD

(2) EL120XCSS – EL240XASD

EL150XCSD – EL180XASD

EL180XCSD – EL240XASD

EL180XCSD – (2) EL090XASD

EL240XCSD – (2) EL120XASD

Residential Cooling Model(s) – Normal Operating Pressures and

Temperatures

Note – Pressures at 80°F dry bulb and 67°F wet bulb entering indoor air temperatures.

EL090XCSS + (2) CX35-60D + (2) EL296UH135XE60D

EL090XCSS + (2) CX35-60C + (2) EL280UH110E48C

EL090XCSS + (2) CX35-60C + (2) EL280UH110E60C
EL090XCSS + (2) CX35-60C + (2) EL280UH110XE60C
EL090XCSS + (2) CX35-60C + (2) EL296UH110XE60C

EL120XCSS + (2) CX35-60C + (2) EL280UH110E60C
EL120XCSS + (2) CX35-60C + (2) EL280UH110XE60C
EL120XCSS + (2) CX35-60C + (2) EL296UH110XE60C 

EL120XCSS + (2) CX35-60D + (2) EL296UH135XE60D

Commercial Heat Pump Model(s) – Normal Operating Pressures and

Temperatures

(2) EL090XPSS – EL240XASD

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