Carrier P, 52C manual Operating Controls, UNIT-MOUNTED Controls

52C,P

SERIES

OPERATING CONTROLS

UNIT-MOUNTED CONTROLS

The controls and components used in the 52C,P cool- ing only or heat/cool units are as follows: the selec- tor switch, the indoor thermostat, the dual capacitor, the temperature limiter, the vent lever, and the fan cycle switch. See Figure 37.

The selector switch is used to determine the mode of operation: heat, cool, fan, or off. The indoor thermostat controls the room ambient temperature and cycles the heater or the compressor based on the selector switch setting. The dual capacitor aids in the start-up of the compressor and the fan motor. The temperature limiter is integrated into the control box top cover located under front panel. It is a mechanical device that restricts the amount of rotation of the thermostat. The temperature limiter device may be adjusted by moving the plastic temperature selector tabs to another temper- ature location on the control box. The vent lever is located on the front left side of the chassis. It is a slide mechanism that opens and closes the vent door. The vent control may be accessed by removing the front panel of the unit. The fan cycle switch is used to provide 2 options of fan control. The first option, CON, causes the fan to run continuously. The second option, CYC, causes the fan to cycle on with the compressor or elec- tric heater and off when the thermostat is satisfied.

INDOOR		SELECT0R
		SWITCH
THERMOSTAT
		75
	80	70

8565

90 60

TEMPERATURE
LIMITER
	CON
FAN CYCLE	CYC
SWITCH

The 52C,P heat pump unit contains all the compo- nents of the heat/cool and cooling only unit, and the following additional ones: the outdoor frost thermostat and the reversing valve. The outdoor frost thermostat prevents operation of the unit in the heat pump mode when the outdoor coil temperature drops below 20 F, or at about 35 F outdoor ambient temperature. The unit automatically engages the electric heat strip and disables the compressor under these conditions.

The outdoor frost thermostat has a manual override to place the unit in electric heat mode operation only. The override switch is located behind the front panel on the front side of the unit control box door.

IMPORTANT: Placing the override switch to elec- tric heat mode operation will disable the compres- sor for ALL heating or cooling operations (for all units except RC units). Placing the override switch to electric heat mode operation on RC units will only disable the compressor in heating mode.

The reversing valve allows for operation in reverse cycle heat pump mode. The valve is located in the piping sys- tem and is controlled by the reversing valve solenoid coil. The coil is energized only during the heating mode.

OUTDOOR FROST THERMOSTAT (HEAT PUMP UNITS ONLY)

FIGURE 37 — 52C,P OPERATING CONTROLS

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