The Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Consider the following safety issues:
•Prior to performing any service or maintenance on electrical equipment you must Disconnect All
Power.
•New and unfamiliar tasks should be performed under the supervision of an experienced service technician.
•Personal protective equipment, such as safety glasses and work gloves, should be worn.
•The floor around the work area should be clean and free of debris.
•Make sure tools are the correct tools for job, and that they are working properly and in good condition.
•The 52C,P unit may weigh up to 150 pounds. Use a lifting device or ask for assistance if the unit must be moved.
■INDOOR THERMOSTAT (Heat/Cool and Cool Only Units) (Figure 48) — The thermostat maintains the selected temperature by cycling the compressor on and off during cooling operation and the electric heater during heating operation. The thermostat DOES
NOT switch from heating to cooling, or cooling to heating. If the switch is in the CYCLE position, then the fan will be cycled off when the thermostat satisfies.
To verify the operation of the thermostat switch, a con- tinuity test may be performed as follows:
1.Turn off unit power as described in UNIT DISASSEMBLY section.
2.Remove wire leads from thermostat. Note their locations to ease
FIGURE 48 — INDOOR THERMOSTAT (IT)
CONTACTS, ALL 52CE, PE MODELS
LEGEND (Figures
COMP — Compressor
HTR | — Heater |
IT | — Indoor Thermostat |
OFT | — Outdoor Frost Thermostat |
OL | — Overload |
PLS | — Primary Limit Switch |
SLS | — Secondary Limit Switch |
3.Place one of the leads of the continuity tester on the terminal marked 2, and the other lead on either the terminal marked 1 or the terminal marked 3.
4.Adjust the thermostat up or down to verify the contacts of the switch open and close. When veri- fying continuity of a closed switch, the ohm read- ing should be 0 ohms. An open switch will show OL on the meter.
5.When testing is complete, reconnect the leads.
■INDOOR THERMOSTAT (Heat Pump Units) (Figure 49) — The heat pump indoor thermostat uses a
When the room temperature is more than 4 F cooler than the indoor thermostat setting, the second heating stage of the indoor thermostat engages the electric heat strip. This design feature allows the user to rap- idly warm the room with the electric heat strip by turning the thermostat to its highest setting. When room temperatures approach the desired temperature, the user may adjust the thermostat to a personal comfort setting, which allows for normal heat pump operation.
NOTE: For outdoor coil temperatures below approxi- mately 20 F, the outdoor frost thermostat prevents heat pump mode operation and immediately engages the electric heat strip upon a call for heating. The elec- tric heat strip is NEVER energized at the same time as the compressor.
To verify operation of the heat pump indoor thermo- stat switch, a continuity test may be performed as follows:
1.Turn off unit power as described in UNIT DISASSEMBLY section.
2.Remove wire leads from thermostat. Note their locations to ease
3.To test stage A, place one lead of the continuity tester on the terminal marked 2, and the other lead on either the terminal marked 1 or the termi- nal marked 3.
4.Adjust the thermostat up or down to verify the contacts of the switch open and close. When veri- fying continuity of the closed switch, the reading on the meter should be 0 ohms. An open switch will show OL on the meter.
5.To test stage B contacts, place one lead of the con- tinuity tester on contact 5 and the other lead on either contact 4 or contact 6.
6.Adjust the thermostat up or down to verify the contacts of the switch open and close as in Step 4.
7.When testing is complete, reconnect the leads.
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