User manual MITSUBISHI SEZ-KD35VA 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. [. . . ] Turn the power on again and check restart after inserting connector again. Replace indoor controller board if there is abnormal difference with actual room temperature. Turn the power off, and on again to operate after check. Cause 1 Defective thermistor characteristics 2 Contact failure of connector (CN20) on the indoor controller board (Insert failure) 3 Breaking of wire or contact failure of thermistor wiring 4 Defective indoor controller board P1 P2 Pipe temperature thermistor/Liquid (TH2) 1 The unit is in three-minute resume prevention mode if short/open of thermistor is detected. (The unit returns to normal operation, if it has normally reset. ) 2 Constantly detected during cooling, drying, and heating (except defrosting) operation. Short: 90: or more Open: -40: or less 1 Defective thermistor characteristics 2 Contact failure of connector (CN44) on the indoor controller board (Insert failure) 3 Breaking of wire or contact failure of thermistor wiring 4 Defective refrigerant circuit is causing thermistor temperature of 90: or more or -40: or less. 5 Defective indoor controller board 1­3 Check resistance value of thermistor. 2 Check contact failure of connector (CN44) on the indoor controller board. Turn the power on again and check restart after inserting connector again. 4 Check pipe <liquid> temperature with remote controller in test run mode. If pipe <liquid> temperature is extremely low (in cooling mode) or high (in heating mode), refrigerant circuit may have defective. 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. 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. 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. [. . . ] NG OK END Replace indoor controller board. OK Check the operation. NG END Replace indoor controller board. Replace the fan motor. 32 7 DISASSEMBLY PROCEDURE Exercise caution when removing heavy parts. SEZ-KD25VA(L). TH SEZ-KD35VA(L). TH SEZ-KD50VA(L). TH SEZ-KD60VA(L). TH SEZ-KD71VA(L). TH 1. Removing the control box cover (1) Remove the two fixing screws on the cover (A) to remove it. Fig. Remove the control box cover according to the procedure in section [1]. [. . . ]