Panasonic CS-A18BD3P Service Manual

Panasonic CS-A18BD3P Service Manual Manual pdf 58 page image

Emergency operation•••• Emergency operation of outdoor unitEmergency operation can be carried out by setting theDSW1 switch on the printed circuit board inside theoutdoor unit to the EMERGENCY position. However,emergency operation is only carried out when anabnormality is detected by the indoor/outdoortemperature thermistors.The resistance values of each thermistor are measuredas shown in the table below to determine if there is anabnormality.Thermistor resistance tableTemperature Resistance value (kΩ) ± 5%Room temperaturethermistorPipe temperaturethermistor-20°C 205.8 197.8-10°C 114.6 111.9-5°C 87.3 85.40°C 67.0 65.85°C 51.8 51.010°C 40.4 39.915°C 31.7 30.720°C 25.1 25.025°C 20.0 20.030°C 16.1 16.040°C 10.4 10.650°C 6.9 7.160°C 4.7 4.970°C ___ 3.580°C ___ 2.590°C ___ 1.8100°C ___ 1.4The pipe temperature thermistor resistance value arethe same for the indoor and outdoor units.occurred>−−−− Set only the thermistor which shows an abnormalityto the condition shown in the table below to carry outemergency operationThermistor Cooling mode Heating modeIndoor unit Room temperature Fixed at 25°CRoom temperature Shorted OpenThermistor Cooling mode Heating modeOutdoor unit DischargetemperatureOpen ShortedHeat exchangeroutlet temperatureShorted Open−−−− Refer to the circuit diagram for the connectionlocations for each thermistor.−−−− If there is an abnormality in the room temperaturethermistor, the temperature will be fixed at 25°Cregardless of the remote control unit display.NOTE:−−−− Any abnormalities detected by the temperaturethermistors are ignored during emergency operation,so that long-term operation in this mode should beavoided.−−−− After emergency mode operation has beencompleted and normal operation is to be resumed,turn the power supplies for the indoor and outdoorunits off and return the DIP switch to the NORMALposition.−−−− Self-diagnosis LEDS 4 to 6 will flash duringemergency operation.25 EMERGENCY OPERATION58