Si04-402A Function of ThermistorFunction and Control 272. Function of Thermistor2.1 Heat Pump ModelA Outdoor HeatExchangerThermistor (DCB)1. The outdoor heat exchanger thermistor is used for controlling target discharge temperature.Set a target discharge temperature depending on the outdoor and indoor heat exchangertemperature.Control the electronic expansion valve opening so that the target discharge temperature canbe obtained.2. The outdoor heat exchanger thermistor is used for detecting the discharge thermistordisconnected when cooling.When the temperature of the discharge piping is lower than the temperature of outdoor heatexchanger, a disconnected discharge thermistor can be detected.3. The outdoor heat exchanger thermistor is used for high pressure protection during coolingoperation.B DischargePipe Thermistor(DOT)1. The discharge pipe thermistor is used to control the discharge pipe.If the temperature of discharge pipe (used in place of the inner temperature of thecompressor) rises abnormally, the operating frequency drops or the operation must behalted.2. The discharge pipe thermistor is used for detecting the discharge thermistor disconnected.C Indoor HeatExchangerThermistor (DCN)1. The indoor heat exchanger thermistor is used for controlling target discharge pipetemperature.Set a target discharge pipe temperature according to the outdoor and indoor heat exchangertemperature.Control the electronic expansion valve so that the target discharge pipe temperature can beobtained.2. The indoor heat exchanger thermistor is used to prevent freezing.During the cooling operation, if the temperature drops abnormally, the operating frequencybecomes lower, then the operation must be halted.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 operationis halted becomes -1°C, it is assumed as icing.4. During heating: the indoor heat exchanger thermistor is used for detecting the dischargepipe thermistor disconnected.When the discharge pipe temperature become lower than an indoor heat exchangertemperature, a disconnected discharge pipe thermistor can be detected.Four way valveCompressor (R3305)ACB
