Carrier 52S Series Service Technician Manual

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Carrier 52S Series Service Technician Manual Manual pdf 24 page image

OPERATING CONTROLSThe controls and components used in the 52S coolingonly or heat/cool units are as follows: the selectorswitch, the indoor thermostat, the dual capacitor, thetemperature limiter, the vent lever, and the fan cycleswitch (Figure 45).The selector switch is used to determine the mode of op-eration: heat, cool, fan, or off. The indoor thermostatcontrols the room ambient temperature and cycles theheater or the compressor based on the selector switchsetting. The dual capacitor aids in the start-up of thecompressor and the fan motor. The temperature limiteris mounted on the thermostat under the escutcheon.It is a mechanical device that restricts the amount of ro-tation of the thermostat. The temperature limiter de-vice may be adjusted by moving the plastic temperatureselector tabs to another temperature location on thedevice. The vent lever is located in the upper right cor-ner of the control box. It is a slide mechanism thatopens and closes the vent door. The control may be ac-cessed by removing the front panel of the unit. The fancycle 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 onwhen venting, heating, or cooling is requested and offwhen the thermostat is satisfied.The 52S heat pump unit contains all the componentsof the heat/cool and cooling only unit, and the follow-ing additional ones: the outdoor frost thermostat and thereversing valve. The outdoor frost thermostat preventsoperation of the unit in the heat pump mode when theoutdoor coil temperature drops below 15 F, or at about30 to 35 F outdoor ambient temperature (about 40 to45 F outdoor ambient temperature for 1999 models). Theunit automatically engages the electric heat strip un-der these conditions.The outdoor frost thermostat has a manual override toplace the unit in electric heat mode operation only.The override switch is located behind the front panel onthe right side of the unit control box. Placing the over-ride switch into electric heat mode operation will dis-able the compressor for ALL heating or cooling operations.The reversing valve allows for operation in reverse cycleheat pump mode. The valve is located in the piping sys-tem and is controlled by the reversing valve solenoidcoil. The coil is energized only during the heating mode.For 52S remote control (RC) units, all controls arelocated on the wall mounted thermostat except the ventlever and outdoor thermostat. Remote control is afactory-installed option only. There are 2 styles of ther-mostats qualified for use with 52S series Remote Con-trol units. See Figures 46 and 47. For all other 52S units,room controls are located on the unit or unit controlpanel. Remote control units do not have a fan cycleswitch.See Figure 48 for sample control panels and Figure 49for controls locations.FIGURE 45 — TYPICAL 52S UNITOPERATING CONTROLSFIGURE 46 — MANUAL THERMOSTATRCD P/N TSTATCCPAC01-A or TSTATCCPHP01-AFIGURE 47 — PROGRAMMABLE THERMOSTAT52SSERIES24