Service manual

General Functionality Si04-115
18 Main Function
1. General Functionality
1.1 Functions of Thermistors
Location of
thermistors
The thermistors on the drawing below are used to control the system. This control secures a
proper cooling and prevents problems of the unit:
Frequency
control
The following table shows the thermistors that control the frequency:
with
#
: available functions and — : no available functions.
OUTDOOR UNIT
M
COOLING
HEATING
FIELD PIPING
FIELD PIPING
R1T
R2T
INDOOR UNIT
R1T
R2T
M
(R1899)
Controls
Outdoor heat
exchanger
thermistor
Outdoor
ambient
temperature
thermistor
Indoor ambient
temperature
thermistor
Indoor heat
exchanger
thermistor
Symbol R2T R1T R1T R2T
Freeze-up prevention.
Refer to page 19.
———#
Peak cut off. Refer to page
19.
———#
Defrost. Refer to page 23. ##— #
High pressure limitation in
heating. Refer to page 19.
# ——#