Vaillant V 10-025 NHI, Training Manual

Page: 39 / 56

Split Type Installation Manual
39 EN
PCB Explanation 9
9.3 Function of Main Thermistor
Note:
A: Outdoor suction temperaturesensor
B: Exhaust temperature sensor
C: Indoor heat-exchangesensor
Outdoor Suction Temperature Sensor
The outdoor heat exchanger thermistor is used for
controlling target discharge temperature.
The system sets a target discharge temperature
according to the outdoor and indoor heat exchanger
temperature, and controls the electronic expansion valve
opening so that the target discharge temperature can be
obtained.
Exhaust Temperature Sensor
The discharge pipe thermistor is used for controlling
temperature of the discharge pipe.
If the temperature of discharge pipe (used in place of
the inner temperature of the compressor) rises
abnormally, the operating frequency drops or the
operation halts.
Indoor heat-exchange sensor
1. The indoor heat exchanger thermistor is used for
controlling target discharge temperature.
The system sets a target discharge temperature
according to the outdoor and indoor heat exchanger
temperature, and controls the electronic expansion
valve opening so that the target discharge
temperature can be obtained.
2. The indoor heat exchanger thermistor is used for
preventing freezing.During the cooling operation,
if the temperature drops abnormally, the operating
frequency becomes lower, then the operation halts.
3. The indoor heat exchanger thermistor is used for
anti-icing control.During the cooling operation, if the
heat exchanger temperature in the room where
operation is halted becomes -1°C, it is assumed as
icing.