User manual MITSUBISHI SEZ-KD50VA TECHNICAL AND SERVICE MANUAL

[. . . ] SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS September 2007 No. HWE07110 REVISED EDITION-B TECHNICAL & SERVICE MANUAL Indoor unit [Model names] SEZ-KD25VA(L) SEZ-KD35VA(L) SEZ-KD50VA(L) SEZ-KD60VA(L) SEZ-KD71VA(L) [Service Ref. ] SEZ-KD25VA(L). TH SEZ-KD35VA(L). TH SEZ-KD50VA(L). TH SEZ-KD60VA(L). TH SEZ-KD71VA(L). TH CONTENTS 1. PART NAMES AND FUNCTIONS ········2 2. SPECIFICATIONS·································5 3. OUTLINES AND DIMENSIONS··········18 4. [. . . ] 5 Check pipe <liquid> temperature with remote controller in test run mode. If there is extreme difference with actual pipe <liquid> temperature, replace indoor controller board. Turn the power off, and on again to operate after check. P4 (5701) Contact failure of drain float switch (CN4F) 1 Contact failure of connector 1 Extract when the connector of drain float (Insert failure) switch is disconnected. (3 and 4 of connector CN4F is not short-circuited. ) 2 Defective indoor controller 2 Constantly detected during operation. board Drain overflow protection operation 1 Suspensive abnormality, if drain float switch is detected to be underwater for 1 minute and 30 seconds continuously with drain pump on. 2 Drain pump is abnormal if the condition above is detected during suspensive abnormality. 3 Constantly detected during drain pump operation. 1 Malfunction of drain pump 2 Defective drain Clogged drain pump Clogged drain pipe 3 Defective drain float switch Catch of drain float switch or malfunction of moving parts cause drain float switch to be detected under water (Switch On) 4 Defective indoor-controller board 1 Check contact failure of float switch connector. Turn the power on again and check after inserting connector again. 2 Operate with connector (CN4F) short-circuited. Replace indoor controller board if abnormality reappears. 2 Check drain function. P5 3 Remove drain float switch connector CN4F and check if it is short (Switch On) with the moving part of float switch UP, or OPEN with the moving part of float switch down. Replace float switch if it is short with the moving part of float switch down. 4 Replace indoor controller board if it is shortcircuited between 3-4 of the drain float switch connector CN4F and abnormality reappears. It is not abnormal if there is no problem about the above-mentioned 1~4 Turn the power off, and on again to operate after check. 25 Error Code Abnormal point and detection method Freezing/overheating protection is working 1 Freezing protection (Cooling mode) The unit is in six-minute resume prevention mode if pipe <liquid or condenser/evaporator> temperature stays under -15: for three minutes after the compressor started. Abnormal if it stays under -15: for three minutes again within 16 minutes after six-minute resume prevention mode. 2 Overheating protection (Heating mode) The units is in six-minute resume prevention mode if pipe <Liquid or condenser / evaporator> temperature is detected as over 70: after the compressor started. Abnormal if the temperature of over 70: is detected again within 10 minutes after six-minute resume prevention mode. Cause (Cooling or drying mode) 1 Clogged filter (reduced airflow) 2 Short cycle of air path 3 Low-load (low temperature) operation beyond the tolerance range 4 Defective indoor fan motor · Fan motor is defective. · Indoor controller board is defective. Countermeasure (Cooling or drying mode) 1 Check clogging of the filter. DC Fan motor (FAN MOTOR/ INDOOR CONTROLLER BOARD) 5 Defective outdoor fan control 6 Overcharge of refrigerant 7 Defective refrigerant circuit (clogs) (Heating mode) 1 Clogged filter (reduced airflow) 2 Short cycle of air path 3 Over-load (high temperature) operation beyond the tolerance range 4 Defective indoor fan motor · Fan motor is defective. · Indoor controller board is defective. 5 Check outdoor fan motor. 67 Check operating condition of refrigerant circuit. P6 (Heating mode) 1 Check clogs of the filter. [. . . ] 6 34 Exercise caution when removing heavy parts. 4. Thermistor (Condenser / evaporator) (Liquid pipe) 1. Remove the drain pan according to the procedure in section [3]. Removing the Heat exchanger cover (1) Remove the four fixing screws on the heat exchanger cover (F) to remove it. (F) Fig. [. . . ]