Daikin RXYSQ4-5-6PA7V1B Service Manual

Contents

Troubleshooting by Indication on the Unified ON/OFF Controller SiBE34-802218 Troubleshooting[CHECK 1] Check for causes of rise in high pressureReferring to the Fault Tree Analysis (FTA) shown below, probe the faulty points.Short circuitRise in highpressureLocalpressureriseHigh piperesistanceStop valve closedBent or crashed pipeClogging of foreignparticles←Check to be sure the stop valve is open.←Conduct visual checks for pipe conditions.←Is there any temperature difference caused beforeand after the filter or branch pipe.[In cooling]If the outdoor unit electronicexpansion valve is throttled:(See *1.)Faulty outdoorunit electronicexpansion valveFaulty indoorunit electronicexpansion valveFaulty valve coilFaulty valve body←Are the coil resistance and insulation normal?A temperature difference in excess of 10°Cbetween the inlet and the outlet is deemed to be abnormal.FaultycontrolFaulty high pressure sensorFaulty control PCB←Are the electrical characteristics normal?←Is the pressure value checked with the Service Checkercorresponding to the measurement of the pressure sensor?←Are the coil resistance and insulationnormal?Faulty highpressurecontrol Faulty valve coilFaulty valve body[In heating]If the indoor unit electronicexpansion valve excessivelythrottled:(See *2.)FaultycontrolFaulty high pressure sensorFaulty indoor unitliquid pipe thermistorFaulty control PCB←Are the electrical characteristics normal?←In the connector properly connected?Are the thermistor resistance characteristics normal?←Is the pressure value checked with the ServiceChecker corresponding to the measurement of thepressure sensor?[In cooling]High suctionairtemperatureof thecondenser[In heating]High suction airtemperatureof outdoor unitShort circuitHigh ambient temperature←Is the suction air temperature not more than46°C?←Is the outdoor temperature not more than 46°C?High suctionair temperatureof indoor unit High ambient temperature←Is the suction air temperature not more than 27°C?←Is the indoor temperature not more than 27°C?Faulty suction air thermistor of indoor unitHigh suction air temperature of outdoor unitFaulty outdoor temperature thermistor of outdoor unit←Is the connector properly connected?Are the thermistor resistance characteristics normal?←Is the outdoor temperature not more than 16°CWB?←Is the connector properly connected?Are the thermistor resistance characteristics normal?Degradationin condensingcapacityDirty condenserMixing of non-condensable gas←Is the heat exchanger clogged? (In cooling)←Is air or else mixed in the refrigerant system?Decreasedfan airflowrateDecreasedfanoutputFaulty fanmotor ←Can the fan motor be rotated with hands?Are the motor coil resistance andinsulation normal?←If a spare PC board is mounted, is thecapacity setting properly made?Faulty controlPC board(Includingcapacity setting)High airpassageresistanceDirty filter ←Is the air filter clogged?Obstacle ←Is there any obstacle in the air passage?Excessive refrigerant chargingImproper model selection [In heating]←Refer to P.173.←Is the indoor unit too small compared tothe large-sized outdoor unit?*1: In cooling, it is normal if the outdoor unit electronic expansion valve (EV1) is fully open.*2: In heating, the indoor unit electronic expansion valve is used for “subcooled degree control”.(For details, refer to “Electronic Expansion Valve Control” on P.72.)C: SDK04009