TABLE 5
Thermostat Load - Amps
FIELD WIRE SIZE FOR 24 VOLT THERMOSTAT CIRCUITS
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| SOLID COPPER WIRE - AWG |
| |||
3.0 | 16 | 14 | 12 | 10 | 10 | 10 |
2.5 | 16 | 14 | 12 | 12 | 10 | 10 |
2.0 | 18 | 16 | 14 | 12 | 12 | 10 |
| 50 | 100 | 150 | 200 | 250 | 300 |
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| Length of Run - Feet (1) |
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(1) Wire length equals twice the run distance.
NOTE: The condensing unit is shipped with a holding charge of dry nitrogen which must be purged from the unit before evacuation.
1.Since the condensing unit itself must be evacuated, open the suction, discharge and liquid
2.Use a refrigeration type vacuum pump capable of evacuation in the 500 micron range.
3.Connect the vacuum pump to the service manifold assembly with a pressure gauge that will read 30 inches vacuum. Connect the service manifold to the suction line schrader valve port.
4.With an accurate scale, 1⁄2 oz., set refrigerant tank up so its weight can be measured while in a position to charge liquid. (Unit must be off.) Energize liquid line solenoid valve by wiring valve to 24V power supply (or open by manual stem if applicable).
5.Connect to the liquid
6.Triple evacuate the system.
7.The refrigerant system will now be free of noncondensables.
8.Remove vacuum pump from
9.Before tightening, purge tank and service valve hose.
CHARGING HINTS
SYMPTOM | POSSIBLE CAUSE | REMEDY |
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High head pressure | a. Air flow to or from condenser restricted or | a. Remove obstruction, relocate condensing unit, |
| dirty condenser | if necessary clean condenser. |
| b. Faulty condenser fan or motor. | b. Replace. |
| c. Overcharge of refrigerant | c. Reduce charge. |
| d. Air in system. | d. Evacuate and recharge. |
Low head pressure | a. Short of refrigerant. | a. Check for leak, add charge. |
| b. Low evaporator air flow. | b. Increase blower speed, check filters. |
Low vapor & | a. Short of refrigerant. | a. Check for |
hot compressor |
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Excessive sweating | a. Low indoor airflow | a. Increase speed of air handler blower or reduce |
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| |
| b. Excess refrigerant | b. Slowly reduce charge. |
10.Note weight of refrigerant tank.
11.
12.Close off service valve to liquid port and note weight of refrigerant tank.
13.
14.Charge unit per chart.
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