Carrier 50TCN120 Instrucciones De Instalación página 44

Heating (If the Heating Accessory is installed)
- To start up the unit, turn on the power supply.
Turn the thermostat to HEAT, set it above the room
temperature and the fan to AUTO.
The fi rst stage of the thermostat powers up the fi rst
electric heating stage; the second stage energizes
the second electric heating stage if installed. Check
the effects of the heating on the air supply grids.
If the unit does not energize, set the limit switch
(located in the evaporator fan coil) by pressing the
button located between the switch terminals.
TO TURN OFF THE UNIT – Turn the system
selection switch to OFF. If the heating selector
handle is set below the room temperature, the
unit shuts down temporarily until the room
temperature falls below the thermostat setpoint.
Safety Help - A light welded joint at the suction
line in the low-pressure service port will provide
the pressure relief under abnormal temperature
and pressure conditions.
Ventilation (Continuous Ventilation) - Turn the
fan and the system selector switch respectively
to ON and OFF. The evaporator fan operates
continuously to provide the air circulation.
When the control thermostat must be installed away from the Roof Top, the control contactors
may be knocked over by the voltage drop in the cables, in which case incorporate a relay plate
according to the electrical diagram below (Fig. 14 ).
44
LIGHT BLUE
GRAY
LIGHT BLUE
VIOLET
Fig. 14
Operation Sequence
COOLING – When cooling is selected at the
thermostat, the terminals G and Y1 power up.
The inside fan contactor (evaporator) and the no. 1
compressor contactor (C1) power up and start up
the evaporator fan motor (IFC), the compressor no.
1 and the condenser fan. While the unit is cooling,
the condenser fan motor operates continuously.
If the second cooling stage is activated from the
thermostat energizing Y2, the compressor no. 2
contactor (C2) is powered up and starts up the
compressor starts up.
HEATING - (If the Optional or Accessory heating
is installed).
When heating is selected in the thermostat
through the terminal W1, the IFC board and the
heating no. 1 contactor (HC1) are energized. For
units equipped with two heating stages, and an
additional heating is necessary, HC2 is energized
through the W2.
ORANGE
ORANGE