System
Unit Start-Up
Once the unit is properly installed and
are complete, start the unit by turning the System Switch on the indoor ther- mostat to either HEAT, COOL or AUTO. The system should operate normally.
Sequence of Operation
General
Operation of the system cooling (and optional heating) cycles is controlled by the position of the system switch on the room thermostat. Once the system switch is placed in either the HEAT or COOL position, unit opera- tion is automatic. The optional auto- matic changeover thermostat, when in the AUTO position, automatically changes to heat or cool with sufficient room temperature change.
Evaporator Fan (Indoor Supply Air)
The evaporator fan is controlled by an ON/AUTO switch on the room ther- mostat. With the switch positioned at AUTO and the system operating in the cooling mode, fan operation coin- cides with the cooling run cycles. If the system is equipped with heat and is operating in the heating mode while the fan switch is at AUTO, fan operation coincides with the heating run cycles. When the fan switch is positioned at ON, fan operation is continuous.
Cooling Mode
When the room thermostat system switch is positioned at COOL and the fan switch is at AUTO, the condenser fan relay energizes on a call for cool- ing. When the contacts of the con- denser fan relay close, operation of the condenser fan begins. The evapo- rator fan contactor also energizes on a call for cooling and initiates evapora- tor fan operation.
On units with dual circuits, the second stage of cooling is initiated as a result of the
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