Page 1: Table Of Contents
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS September 2024 No. OCH870 SERVICE MANUAL R454B [Model Name] [Service Ref.] Note: • This manual describes PUZ-AK24NLHZ-U1 PUZ-AK24NLHZ service data of the outdoor units only. PUZ-AK30NLHZ-U1 PUZ-AK30NLHZ PUZ-AK36NLHZ-U1 PUZ-AK36NLHZ PUZ-AK42NLHZ-U1 PUZ-AK42NLHZ PUZ-AK48NLHZ-U1 PUZ-AK48NLHZ SUZ-AK24NLHZ-U1 SUZ-AK24NLHZ...
Page 2: Reference Manual
REFERENCE MANUAL INDOOR UNIT SERVICE MANUAL Service Manual No. Model Name Service Ref. Parts Catalog No. OCH856 PLA-AE12/18/24/30/36/42/48NL PLA-AE12/18/24/30/36/42/48NL-U1 OCB856 OCH860 PCA-AK24/30/36/42NL PCA-AK24/30/36/42NL-U1 OCB860 OCH859 PKA-AK24/30/36NL PKA-AK24/30/36NL-U1 OCB859 HWE24030 PEAD-AA12/18/24/30/36/42NL PEAD-AA12/18/24/30/36/42NL-U1 BWE024030 — PAA-AA/BA/CA18/24/30/36/42NL MD-2025-K010 SAFETY PRECAUTION MEANINGS OF SYMBOLS DISPLAYED ON THE UNIT Refrigerant WARNING This unit uses a flammable refrigerant.
Page 3 2-1. ALWAYS OBSERVE FOR SAFETY Before obtaining access to terminal, all supply circuits must be disconnected. Preparation before the repair service. • Prepare the proper tools. • Prepare the proper protectors. • Provide adequate ventilation. • After stopping the operation of the air conditioner, turn off the power-supply breaker. •...
Page 4 2-2. CAUTIONS RELATED TO NEW REFRIGERANT Cautions for units utilizing refrigerant R454B Use a vacuum pump with a reverse flow check Use new refrigerant pipes. valve. In the case of using the existing pipes for R22, R410A, Vacuum pump oil may flow back into refrigerant cycle and be careful with the following: that can cause deterioration of refrigerant oil, etc.
Page 5 [1] Warning for service (1) Do not alter the unit. (2) For installation and relocation work, follow the instructions in the Installation Manual and use tools and pipe components specifically made for use with refrigerant specified in the outdoor unit installation manual. (3) Ask a dealer or an authorized technician to install, relocate and repair the unit.
Page 6: Cautions For Service
[2] Cautions for service (1) Perform service after recovering the refrigerant left in unit completely. (2) Do not release refrigerant in the air. (3) After completing service, charge the cycle with specified amount of refrigerant. (4) If moisture or foreign matter might have entered the refrigerant piping during service, ensure to remove them. [3] Additional refrigerant charge When charging directly from cylinder (1) Check that cylinder for R454B on the market is a syphon type.
Page 7 [4] Cautions for unit using R454B refrigerant Basic work procedures are the same as those for conventional units using refrigerant R410A. However, pay careful attention to the following points. (1) Information on servicing (1-1) Checks on the Area Prior to beginning work on systems containing FLAMMABLE REFRIGERANTS, safety checks are necessary to ensure that the risk of ignition is minimized.
Page 8 (2) Repairs to Sealed Components Sealed electrical components shall be replaced. (3) Repair to intrinsically Safe Components Intrinsically safe components must be replaced. (4) Cabling Refer to 6.1 in the installation manual. (5) Detection of Flammable Refrigerants Refer to 4.4 in the installation manual. (6) Removal and Evacuation Refer to 1.2 in the installation manual.
Page 9: Service Tools
[5] Service tools Use the below service tools as exclusive tools for R454B refrigerant. Tool name Specifications Gauge manifold · Only for R454B · Use the existing fitting specifications . · Use high-tension side pressure of 768.7 psig [5.3 MPa.G] or over. Charge hose ·...
Page 10 2-3. CAUTIONS FOR REFRIGERANT PIPING WORK New refrigerant R454B is adopted for replacement inverter series. Although the refrigerant piping work for R454B is same as for R22/R410A, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the working pressure of R454B is 1.6 time higher than that of R22, their sizes of flared sections and flare nuts are different.
Page 11 3. Tools for R454B (The following table shows whether conventional tools can be used or not.) Tools and materials R454B tools Can R22 tools be used ? Can R410A tools be used ? Gauge manifold Air purge, refrigerant charge Tool exclusive for R454B and operation check Charge hose Tool exclusive for R454B...
Page 12 2-4. Minimum installation area ■ Indoor units Install in a room with a floor area of Amin or more, corresponding to refrigerant quantity M (factory-charged refrigerant + locally added refrigerant). See table below. * For the factory-charged refrigerant amount, refer to the spec nameplate or installation manual. For the amount to be added locally, refer to the installation manual.
Page 13: Features
FEATURES PUZ-AK24NLHZ PUZ-AK30NLHZ PUZ-AK36NLHZ PUZ-AK42NLHZ PUZ-AK48NLHZ SUZ-AK24NLHZ SUZ-AK30NLHZ SUZ-AK36NLHZ SUZ-AK48NLHZ CHARGELESS SYSTEM PRE-CHARGED REFRIGERANT IS SUPPLIED FOR PIPING LENGTH AT SHIPMENT. Maximum 100 ft, 30 m The refrigerant circuit with LEV(Linear Expansion Valve) and power receiver always control the optimal refrigerant level regard- less of the length of piping.
Page 14: Specifications
SPECIFICATIONS Service Ref. PUZ-AK24NLHZ-U1 PUZ-AK30NLHZ-U1 PUZ-AK36NLHZ-U1 Power Phase Single Frequency 60 Hz supply Voltage 208/230 V Inverter Input MOCP Breaker size External finish Munsell 3Y 7.8/1.1 Heat exchanger Plate fin coil (Ring) Defrost method Reverse cycle Crankcase heater ― Compressor...
Page 15 Service Ref. PUZ-AK42NLHZ-U1 PUZ-AK48NLHZ-U1 Power Phase Single Frequency 60 Hz supply Voltage 208/230 V Inverter Input MOCP Breaker size External finish Munsell 3Y 7.8/1.1 Heat exchanger Plate fin coil (Ring) Defrost method Reverse cycle Crankcase heater ― Compressor Hermetic Model MRK53FFJMC-L Motor output Starter type...
Page 16 Service Ref. SUZ-AK24NLHZ-U1 SUZ-AK30NLHZ-U1 SUZ-AK36NLHZ-U1 SUZ-AK48NLHZ-U1 Power Phase Single Frequency 60 Hz supply Voltage 208/230 V Inverter Input MOCP Breaker size External finish Munsell 3Y 7.8/1.1 Heat exchanger Plate fin coil (Ring) Defrost method Reverse cycle Crankcase heater ― Compressor Hermetic Model MRK36FFGMC...
Page 17: Data
100ft 110ft 120ft 130ft 140ft 150ft 160ft 165ft 170ft 180ft 190ft 200ft 210ft 220ft 230ft 240ft 245ft charged 15m 18m 21m 24m 27m 30m 33m 37m 40m 43m 46m 49m 50m 52m 55m 58m 61m 64m 67m 70m 73m 75m PUZ-AK24NLHZ-U1 PUZ-AK30NLHZ-U1 PUZ-AK36NLHZ-U1...
Page 18: Noise Criterion Curves
5-3. NOISE CRITERION CURVES PUZ-AK24NLHZ PUZ-AK30NLHZ PUZ-AK36NLHZ PUZ-AK42NLHZ SPL(dB) MODE LINE MODE SPL(dB) LINE SUZ-AK24NLHZ PUZ-AK48NLHZ COOLING COOLING SUZ-AK30NLHZ SUZ-AK48NLHZ HEATING HEATING SUZ-AK36NLHZ NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 APPROXIMATE THRESHOLD OF HEARING FOR APPROXIMATE CONTINUOUS...
Page 19: Standard Operation Data
PLA-AE30NL PLA-AE36NL Phase Single Cycle 60 Hz Voltage 208/230 V Current 0.49 A 0.59 A 0.98 A Outdoor unit model PUZ-AK24NLHZ PUZ-AK36NLHZ PUZ-AK36NLHZ Phase Single Cycle 60 Hz Voltage 208/230 V Current 6.06 A 7.33 A 9.11 A 8.71 A 10.56 A...
Page 20 Representative matching PLA-AE42NL PLA-AE48NL Mode COOLING HEATING COOLING HEATING Total Capacity Btu/h 42,000 54,000 48,000 60,000 Input 3,530 4,350 4,560 5,190 Indoor unit model PLA-AE42NL PLA-AE48NL Phase Single Cycle 60 Hz Voltage 208/230 V Current 1.05 A 1.05 A Outdoor unit model PUZ-AK42NLHZ PUZ-AK48NLHZ Phase...
Page 21 Representative matching SVZ-AP24NL SVZ-AP30NL SVZ-AP36NL Mode COOLING HEATING COOLING HEATING COOLING HEATING Total Capacity Btu/h 23,800 28,000 28,000 34,000 36,000 40,000 Input 2,030 2,690 2,150 2,910 3,410 3,620 Indoor unit model SVZ-AP24NL SVZ-AP30NL SVZ-AP36NL Phase Single Cycle 60 Hz Voltage 208/230 V Current 1.40 A...
Page 22: Outlines And Dimensions
OUTLINES AND DIMENSIONS Unit: mm<in> OCH870...
Page 23: Wiring Diagram
WIRING DIAGRAM PUZ-AK24NLHZ PUZ-AK30NLHZ PUZ-AK36NLHZ SUZ-AK24NLHZ SUZ-AK30NLHZ SUZ-AK36NLHZ OCH870...
Page 24 PUZ-AK42NLHZ PUZ-AK48NLHZ SUZ-AK48NLHZ OCH870...
Page 25: Wiring Specifications
WIRING SPECIFICATIONS 8-1. INDOOR UNIT POWER SUPPLIED FROM OUTDOOR UNIT The following illustrations show available connection patterns. The outdoor unit power supply patterns vary on each model. 1:1 System 1:1 System (Separate indoor unit/outdoor unit power supplies) Outdoor unit power supply Outdoor unit power supply Wiring circuit breaker or isolating switch Wiring circuit breaker or isolating switch...
Page 26 208/230 V Single phase Isolator 3 poles isolator A-Control A-Control Outdoor Unit Indoor Unit Warning: In the case of A-control wiring, there is high voltage potential on the S3 terminal caused by electrical circuit design that has no electrical insulation between power line and communication signal line. Therefore, please turn off the main power supply when servicing.
Page 27 8-3. M-NET WIRING METHOD Points to notice: (1) Outside the unit, transmission wires should stay away from electric wires in order to prevent electromagnetic noise from making an influence on the signal communication. Place them at intervals of more than 5 cm [2 in]. Do not put them in the same conduit tube.
Page 28 8-3-1. M-NET address setting In A-control models, M-NET address and refrigerant address should be set only for the outdoor unit. Similar to CITY MULTI series, there is no need to set the address of outdoor unit and remote controller. To construct a central control system, the setting of M-NET address should be conducted only upon the outdoor unit.
Page 29: Refrigerant System Diagram
Refrigerant flow in heating Symbol Parts name Detail COMP Compressor DC inverter rotary compressor (Mitsubishi Electric Corporation) H/P SW High pressure switch (63H) For protection (OFF: 4.15 MPa) REV/V Reversing (4-way) valve (21S4) Change the refrigerant circuit (Heating / Cooling) and for Defrosting...
Page 30 (with service port) Symbol Parts name Detail COMP Compressor DC inverter rotary compressor (Mitsubishi Electric Corporation) H/P SW High pressure switch (63H) For protection (OFF: 4.15 MPa) REV/V Reversing (4-way) valve (21S4) Change the refrigerant circuit (Heating / Cooling) and for Defrosting...
Page 31 9-1. REFRIGERANT COLLECTING (PUMP DOWN) When relocating or disposing of the indoor/outdoor unit, pump down the system following the procedures below so that no refrig- erant is released into the atmosphere. (1) Turn off the power supply (circuit breaker). (2) Connect the low pressure valve on the gauge manifold to the charge plug (low pressure side) on the outdoor unit. (3) Close the liquid stop valve completely.
Page 32 Included Not included service port service port E Local pipe A Stop valve <Liquid side> F Sealed, same way for gas side B Stop valve <Gas side> G Pipe cover C Service port D Open/Close section 9-3. START AND FINISH OF TEST RUN •...
Page 33: Troubleshooting
TROUBLESHOOTING 10-1. TROUBLESHOOTING <Check code displayed by self-diagnosis and actions to be taken for service (summary)> Present and past check codes are logged, and they can be displayed on the control board of outdoor unit. Actions to be taken for service, which depends on whether or not the trouble is reoccurring in the field, are summarized in the table below. Check the contents below before investigating details.
Page 34 10-2. CHECK POINT UNDER TEST RUN 10-2-1. Before test run • After installation of indoor and outdoor units, piping work and electric wiring work, re-check that there is no refrigerant leak- age, loosened connections and incorrect polarity. • Measure impedance between the ground and the power supply terminal block (L1, L2) on the outdoor unit by 500 V Megger and check that it is 1.0 M or over.
Page 35 • Refer to the following tables for details on the check codes. [Output pattern A] Beeper sounds Beep Beep Beep Beep Beep Beep Beep OPERATION · · · Repeated INDICATOR lamp blink pattern Approx. 2.5 s 0.5 s 0.5 s 0.5 s Approx.
Page 36 10-3. SELF-DIAGNOSIS ACTION TABLE <Abnormalities detected when the power is turned on> Note: Refer to indoor unit section for the codes starting with P and E. Check Code Abnormal point and detection method Cause Judgment and action No voltage is supplied to termi- Check following items.
Page 37 Abnormal point and detection method Cause Judgment and action Check Code 63H or TRS connector open Disconnection or contact failure Check connection of 63H or TRS connector Abnormal if 63H or TRS connector circuit of 63H or TRS connector on on outdoor controller circuit board.
Page 38 <Abnormalities detected while unit is operating> Abnormal point and detection method Judgment and action Check Code Cause High pressure (High pressure switch Short cycle of indoor unit – Check indoor unit and repair defect. 63H operated) /High compressor Clogged filter of indoor unit temperature (Thermal protector TRS Decreased airflow caused by operated)
Page 39 Check Code Abnormal point and detection method Cause Judgment and action Open/short circuit of outdoor unit Disconnection or contact failure Check connection of connector (TH4, TH33) on temperature thermistor (TH4, TH33) of connectors (TH4, TH33) on the outdoor controller circuit board. Check break- Abnormal if open (-4˚F [-20°C] or less) or the outdoor controller circuit ing of the lead wire for TH4, TH33.
Page 40 Check Code Abnormal point and detection method Cause Judgment and action Too low superheat due to low discharge Disconnection or loose connec- Check the installation conditions of dis- temperature tion of discharge temperature charge temperature thermistor (TH4). Abnormal if discharge superheat is con- thermistor (TH4) tinuously detected less than or equal to Defective holder of discharge...
Page 41 Check Code Abnormal point and detection method Cause Judgment and action Detailed Abnormal power synchronous Distortion of power source Check the field facility for the power supply. codes signal voltage, noise superimposition • No input of power synchronous Disconnection or loose Check earth wiring.
Page 42 Abnormal point and detection method Cause Judgment and action Check Code Low pressure Stop valve of outdoor unit is Check stop valve. Abnormal if the following conditions are closed during operation. detected for continuously 3 minutes after Leakage or shortage of Check intake superheat.
Page 43 Check Code Abnormal point and detection method Cause Judgment and action Remote controller transmission Contact failure at transmission Check disconnection or looseness of indoor unit or transmission wire of remote controller. error(E0)/signal receiving error(E4) wire of remote controller Set one of the remote controllers “main”. Abnormal if main or sub remote control- All remote controllers are set If there is no problem with the action above.
Page 44 Check Code Abnormal point and detection method Cause Judgment and action Remote controller control board Defective remote controller Replace remote controller. Abnormal if data cannot be read nor- mally from the nonvolatile memory of the remote controller control board. (Check code: E1) (6832, Abnormal if the clock function of remote 6833)
Page 45 Check Code Abnormal point and detection method Cause Judgment and action Indoor/outdoor unit communication Defective transmitting receiving – Turn the power off, and on again to error (Transmitting error) circuit of indoor controller board check. Replace indoor controller board if Abnormal if “1”...
Page 46 Check Code Abnormal point and detection method Cause Judgment and action Pipe temperature Slight temperature difference – Check pipe <liquid or condenser/ <Cooling mode> between indoor room tempera- evaporator> temperature with room tem- Detected as abnormal when the pipe tem- ture and pipe <liquid or con- perature display on remote controller and perature is not in the cooling range 3 min-...
Page 47 <M-NET communication error> Note: “Indoor unit” in the text indicates M-NET board in outdoor unit. Check Code Abnormal point and detection method Cause Judgment and action Address duplicate definition There are 2 or more same Search the unit with same address as abnormali- This error is displayed when transmission address of controller of out- ty occurred.
Page 48 Abnormal point and detection method Cause Judgment and action Check Code NO ACK signal Common factor that has no rela- Always try the following when the error 1. Transmitting side controller detects tion with abnormality source. “A7” occurs. abnormal if a message was transmitted but there is no reply (ACK) that a mes- The unit of former address Turn off the power supply of outdoor unit...
Page 49 From the previous page. Abnormal point and detection method Cause Judgment and action Check Code 4. If displayed address or attribute is During group operation with Same as mentioned in “A7” of the previous indoor unit of multi- refrigerant remote controller, page.
Page 50 Check Code Abnormal point and detection method Cause Judgment and action M-NET NO RESPONSE Transmitting condition is Check transmission waveform or noise on repeated fault because of Abnormal if a message was transmitted transmission wire. noise and the like. and there were reply (ACK) that message Turn off the power supply of outdoor unit Voltage drop and weak signal was received, but response command...
Page 51 Phenomena Factor Countermeasure 4. Even controlling by the IR wireless The pair number settings of the IR wireless remote Check the pair number settings. remote controller no beep is controller and indoor controller board are mismatched. heard and the unit does not start operating.
Page 52 Symptoms: “Please Wait” is kept being displayed on the remote controller. Inspection method and Diagnosis flow Cause troubleshooting Check the display time of “Please Wait” after turning on the main power. 6 minutes 2 minutes or more or less How long is “Please Wait” •...
Page 53 LED display of the indoor controller board Symptoms: Nothing is displayed on the remote controller 1 LED1: LED2: LED3: Inspection method and Diagnosis flow Cause troubleshooting Check the voltage between S1 and S2 on the terminal block (TB4) of the indoor unit. 198 to 253 VAC? Check the voltage among L1 and L2 on the terminal block (TB1) of the...
Page 54 LED display of the indoor controller board Symptoms: Nothing is displayed on the remote controller 2 LED1: LED2: LED3: Inspection method and Diagnosis flow Cause troubleshooting Check the voltage between S1 and S2 on the terminal block (TB4) of the indoor unit. 198 to 253 VAC? Not lighting.
Page 55 LED display of the indoor controller board LED1: Symptoms: Nothing is displayed on the remote controller 3 LED2: LED3: — Inspection method and Diagnosis flow Cause troubleshooting Check the voltage of the terminal block (TB6) of the indoor unit. 10 to 16 VDC? •...
Page 56 • Before repair Frequently Asked Questions Questions From Customers Answers Note Unit does ① The operating display of remote ① Check if power is supplied to air conditioner. not operate controller does not come on. Nothing appears on the display unless power is at all.
Page 57 Questions From Customers Answers Note The room cannot be cooled or heated sufficiently. ① Check the set temperature of remote controller. The outdoor unit cannot be operated if the set temperature is not appropriate. The outdoor unit operates in the following modes. COOL: When the set temperature is lower than the room temperature.
Page 58 Questions From Customers Answers Note Something ③ Air blows out for a while after However, this control is also ③ This is not a malfunction. is wrong applied to the models which HEAT operation is stopped. The blower is operating just for cooling down the with the has no electric heater.
Page 59 Questions From Customers Answers Note A white mist is expelled from the indoor unit. This is not a malfunction. This may occur when the operation is started in the room with high humidity. Water or moisture is expelled from the outdoor COOL: when pipes or piping joints are cooled, they unit.
Page 60: How To Check The Parts
10-5. HOW TO CHECK THE PARTS Checkpoints Parts name Thermistor (TH3) Disconnect the connector then measure the resistance with a multimeter. <Liquid pipe> (Ambient temperature 50 to 86°F [10 to 30°C]) Thermistor (TH4) Normal Abnormal <Discharge> Thermistor (TH6) 160 to 410 kΩ TH33 <2-phase pipe>...
Page 61 Check method of DC fan motor (fan motor/outdoor controller circuit board) Notes · High voltage is applied to the connector (CNF1, 2) for the fan motor. Pay attention to the service. · Do not pull out the connector (CNF1, 2) for the motor with the power supply on. (It causes trouble of the outdoor controller circuit board and fan motor.) Self check Symptom: The outdoor fan cannot rotate.
Page 62 10-6. HOW TO CHECK THE COMPONENTS <Thermistor feature chart> Low temperature thermistors • Thermistor <Liquid pipe> (TH3) • Thermistor <2-phase pipe> (TH6) • Thermistor <Ambient> (TH7) • Thermistor <Suction pipe> (TH32) Thermistor R0 = 15 kΩ ± 3% B constant = 3480 ± 1% =15exp{3480( 273+t –...
Page 63: Linear Expansion Valve
Linear expansion valve (1) Operation summary of the linear expansion valve • Linear expansion valve opens/closes through stepping motor after receiving the pulse signal from the outdoor controller board. • Valve position can be changed in proportion to the number of pulse signal. <Connection between the outdoor controller board and the linear expansion valve>...
Page 64 <Output pulse signal and the valve operation> Output Output The output pulse shifts in the following order. (Phase) Opening a valve: 8 → 7 → 6 → 5 → 4 → 3 → 2 → 1 → 8 ø1 Closing a valve: 1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → 1 ø2 •...
Page 65 (3) How to attach and detach the coil of linear expansion valve PUZ-AK24NLHZ PUZ-AK30NLHZ PUZ-AK36NLHZ SUZ-AK24NLHZ SUZ-AK30NLHZ SUZ-AK36NLHZ <Composition> Linear expansion valve is separable into the main body and the coil as shown in the diagram below. Linear expansion valve...
Page 66 PUZ-AK24NLHZ PUZ-AK30NLHZ PUZ-AK36NLHZ PUZ-AK42NLHZ PUZ-AK48NLHZ SUZ-AK24NLHZ SUZ-AK30NLHZ SUZ-AK36NLHZ SUZ-AK42NLHZ SUZ-AK48NLHZ <Composition> Linear expansion valve is separable into the main body and the coil as shown in the diagram below. Main body Stopper Coil Lead wire <How to detach the coil>...
Page 67: Emergency Operation
10-7. EMERGENCY OPERATION (1) When any check codes shown below is displayed on outdoor unit, or microprocessor for wired remote controller or indoor unit has a failure while no other problems are found, emergency operation will be available by setting the emergency opera- tion switch (SWE) ON and short-circuiting the connector (CN31) on outdoor controller board.
Page 68 (5) Operation data during emergency operation During emergency operation, no communication is performed with the indoor unit, so the data items needed for operation are set to the following values: Operation mode Remarks Operation data COOL HEAT 81°F [27°C] 69°F [20.5°C] Intake temperature (TH1) 41°F [5°C] 113°F [45°C]...
Page 69: Test Point Diagram
10-8. TEST POINT DIAGRAM <CAUTION> TEST POINT is high voltage. Outdoor controller circuit board CNDM CN3S Demand control setting Pump down Test operation : Input of low-level sound Input of Demand signal priority mode from DRED. Forced defrost, : Input of external contact point detect history record reset, CN51...
Page 70 Outdoor power circuit board PUZ-AK24NLHZ Brief Check of POWER MODULE If they are short-circuited, it means that they are broken. PUZ-AK30NLHZ Measure the resistance in the following points (connectors, etc.). PUZ-AK36NLHZ 1. Check POWER MODULE SUZ-AK24NLHZ Check of DIODE circuit SUZ-AK30NLHZ R –...
Page 71 Brief Check of POWER MODULE Outdoor power circuit board If they are short-circuited, it means that they are broken. Measure the resistance in the following points (connectors, etc.). PUZ-AK42NLHZ 1. Check of POWER MODULE PUZ-AK48NLHZ 1 Check of DIODE circuit R1 - P1 , S1 - P1 , R1 - N1 , S1 - N1 SUZ-AK48NLHZ R2 - P4 , S2 - P4 , R2 - N4 , S2 - N4...
Page 72 Outdoor noise filter circuit board PUZ-AK42NLHZ PUZ-AK48NLHZ SUZ-AK48NLHZ LI, NI POWER SUPPLY Voltage of 208/230 VAC is input (Connect to the terminal block (TB1)) M6 2.8 ± 0.2 N·m CNAC 208/230 VAC Connect to the outdoor controller circuit board (CNAC) El, E2, E3, E4 Connect to the electrical parts box...
Page 73 10-9. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS (1) Function of switches The black square (■) indicates a switch position. Type Action by the switch operation Function Effective timing Switch switch When compressor is working Manual defrost* Start Normal in heating operation.* Abnormal history clear Clear Normal...
Page 74 Type of Action by the switch operation Switch Function Effective timing Switch No function — — — Power failure Auto recovery No auto recovery When power supply ON automatic recovery* No function — — — 3,4,6 — Low noise mode Always Model select* —...
Page 75 <Display function of inspection for outdoor unit> The blinking patterns of both LED1(green) and LED2(red) indicate the types of abnormality when it occurs. Types of abnormality can be indicated in details by connecting an optional part “A-Control Service Tool (PAC-SK52ST)” to con- nector CNM on outdoor controller board.
Page 76 Indication Error Outdoor controller Detailed board Check Contents Inspection method reference code* LED1 LED2 page (Green) (Red) 2 blinking 5 blinking Float switch connector open (FS) Check if connector (CN4F) on indoor controller board is not disconnected. Measure resistance value among terminals on drain pump using a multimeter.
Page 77 Indication Error Outdoor controller Detailed board Check Contents Inspection method reference code* LED1 LED2 page (Green) (Red) 4 blinking 1 blinking Abnormality of room temperature Check if connectors (CN20, CN21, CN29 and CN44) on indoor thermistor (TH1) controller board are not disconnected. Measure resistance value of indoor thermistors.
Page 78 <Outdoor unit operation monitor function> [When optional part “A-Control Service Tool(PAC-SK52ST)” is connected to outdoor controller board(CNM)] Digital indicator LED1 displays 2 digit number or code to inform operation condition and the meaning of check code by controlling DIP SW2 on “A-Control Service Tool”. Operation indicator SW2: Indicator change of self-diagnosis SW2 setting...
Page 79 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit Pipe temperature/Liquid (TH3) −58 to194˚F [−50 to 90˚C] −58 to 194 (When the coil thermistor detects 0˚F [-17°C] or below, “–” and temperature are displayed by turns.) ˚F [˚C] (Example) When −10˚F [-23°C];...
Page 80 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit Pipe temperature/Liquid (TH3) on error −58 to 194˚F [−50 to 90˚C] occurring (When the coil thermistor detects 0˚F [-17°C] or −58 to 194 below, “–” and temperature are displayed by turns.) ˚F [˚C] (Example) When −15˚F [-26°C] 0.5 s...
Page 81 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit 0 to 4 The number of connected indoor units (The number of connected indoor units are displayed.) Unit 2 3 4 5 6 Capacity setting display Displayed as an outdoor capacity code Capacity Code...
Page 82 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit Indoor setting temperature 62 to 86˚F [17 to 30˚C] 62 to 86 ˚F [˚C] 2 3 4 5 6 Outdoor pipe temperature/2-phase pipe −58 to 194˚F [−50 to 90˚C] (TH6) (When the temperature is 0˚F [-17°C] or less, “–”...
Page 83 The black square (■) indicates a switch position. Unit SW2 setting Display detail Explanation for display 180 to 500 DC bus voltage (When it is 100 V or more, hundreds digit, tens 180 to 500 digit and ones digit are displayed by turns.) 2 3 4 5 6 0 to 100 Capacity save...
Page 84 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit 0 to 480 LEV-C opening pulse on error occurring (When it is 100 pulse or more, hundreds digit, tens 0 to 480 digit and ones digit are displayed by turns.) Example: When 130 pulse;...
Page 85 The black square (■) indicates a switch position. SW2 setting Display detail Explanation for display Unit 32 to 491˚F [0 to 255°C] Discharge superheat on error occurring (When the temperature is 100˚F or more, hundreds digit, tens digit and ones digit are 32 to 491 displayed by turns.) ˚F [°C]...
Page 86 ■ The black square ( ) indicates a switch position. SW2 setting Display detail Explanation for display Unit Outdoor suction pipe temperature (TH32) −38 to 190˚F [−39 to 88°C] −38 to 190 (When the temperature is 0˚F [-17°C] or less, “–” and temperature are displayed by turns.) Example: When −15°C;...
Page 87: Easy Maintenance Function
EASY MAINTENANCE FUNCTION 11-1. SMOOTH MAINTENANCE Refer to "15-9. SMOOTH MAINTENANCE" for operation procedure. 11-2. GUIDE FOR OPERATION CONDITION Checkpoints into the graph given below. Enter the temperature differences between Operation state is determined according to the plotted areas on the graph. For data measurements, set the fan speed to "Hi"...
Page 88: Function Setting
FUNCTION SETTING 12-1. UNIT FUNCTION SETTING BY THE REMOTE CONTROLLER Each function can be set as necessary using the remote controller. The setting of function for each unit can only be done by the remote controller. Select function available from the table 1. (1) Functions available when setting the unit number to 00 (Select 00 referring to setting the indoor unit number.) <Table 1>...
Page 89: Monitoring The Operation Data By The Remote Controller
MONITORING THE OPERATION DATA BY THE REMOTE CONTROLLER 13-1. HOW TO "MONITOR THE OPERATION DATA" Refer to "15-10. REQUEST CODE" when monitoring the operation data. 13-2. REQUEST CODE LIST Certain indoor/outdoor combinations do not have the request code function; therefore, no request codes are displayed. Description Request content Unit...
Page 90 Description Request content Unit Remarks (Display range) Thermostat ON operating time 0 – 999 Minutes Test run elapsed time 0 – 120 Minutes Not possible to activate maintenance mode during the test run. Indoor unit-Control state – Refer to 13-2-1.Detail Contents in Request Code. Outdoor unit-Control state –...
Page 91 Description Request content Unit Remarks (Display range) Displays postponement code. (" - - " is Outdoor unit - Error postponement history 1 (latest) Code displayed if no postponement code is present) Displays postponement code. (" - - " is Outdoor unit - Error postponement history 2 (previous) Code displayed if no postponement code is present) Displays postponement code.
Page 92 Description Request content Unit Remarks (Display range) – Indoor-Actual intake air temperature −38 ˚F Indoor - Liquid pipe temperature −38 – ˚F – Indoor-Cond./Eva. pipe temperature −38 ˚F Indoor-Fan operating time 0 – 9999 1 hour (After filter is reset) Indoor-Total operating time 0 –...
Page 93 13-2-1. Detail Contents in Request Code Example) Request code "004" Request code Discharge temperature 156°F Ref.address Request code Refrigerant address "00" Request: SELECT Cursor [Operation state] (Request code: "0" ) Relay output state Power currently Data display Display Compressor Four-way valve Solenoid valve supplied to compressor –...
Page 94 [Fan control state] (Request code: "53 ") Data display Fan step correction value by heatsink temperature overheat prevention control Fan step correction value by cool condensation temperature overheat prevention control Display Correction value - (minus) – 1 [Actuator output state] (Request code : "54") Data display Actuator output state 1 Actuator output state 2...
Page 95 [Contact demand capacity] (Request code: "61") Setting content Data display Setting Display Setting value Setting content SW7-1 SW7-2 100% [External input state] (Request code: "62") Input state : Input position Data display Contact demand Silent mode Spare 1 Spare 2 Display Input state input...
Page 96 [Outdoor unit switch setting display (SW1 to SW9, except SW3)] Request codes: "73 to 81" 0: Switch OFF 1: Switch ON 0: Switch OFF 1: Switch ON SW1, SW2, SW6, SW7 Data display Data display 00 00 00 00 00 01 00 01 00 02 00 02...
Page 97 [Indoor unit – Capacity setting information] (Request code: "163" ) Data display Display Capacity setting state Display Capacity setting state See the table on the right. [Wireless pair No. (indoor control board side) setting] (Request code : "165" ) Data display Display Pair No.
Page 98: Disassembly Procedure
DISASSEMBLY PROCEDURE : Indicates the visible parts in the photos/figures. : Indicates the invisible parts in the photos/figures. Notes: The red markings indicate that flammable refrigerant is charged. If you remove the markings, put them back to the original position after the work is completed. OPERATING PROCEDURE PHOTOS/FIGURES 1.
Page 99 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing the electrical parts box Photo 4 (1) Remove the service panel. (See Photo 1) (2) Remove the top panel. (See Photo 1) AK24/30/36 (3) Disconnect the indoor/outdoor connecting wire and the power supply wire from terminal block. Controller circuit board (C.B.) (4) Disconnect the connector CNF1, CNF2, SV2, LEV-A, Electrical...
Page 100 OPERATING PROCEDURE PHOTOS/FIGURES 4. Removing the thermistor <2-phase pipe> (TH6) and Photo 5 thermistor <Ambient>(TH7) (1) Remove the service panel. (See Photo 1) (2) Remove the top panel. (See Photo 1) Electrical parts (3) Disconnect the connectors TH7/6 (red) on the controller cir- cuit board in the electrical parts box.
Page 101 OPERATING PROCEDURE PHOTOS/FIGURES 5. Removing the thermistor <Discharge> (TH4) Photo 7 (1) Remove the service panel. (See Photo 1) (2) Disconnect the connector TH4 (white) on the controller cir- Thermistor AK24/30/36 cuit board in the electrical parts box. <Discharge> Separator Loosen fasteners for lead wires in the electrical parts box.
Page 102 OPERATING PROCEDURE PHOTOS/FIGURES Photo 8 6. Removing the thermistor <Liquid> (TH3), thermistor Thermistor Thermistor <Suction> (TH32), thermistor <Comp. surface> (TH33) and <Suction> <Liquid> (TH3) AK24/30/36 (TH32) thermal protector (TRS) (1) Remove the service panel. (See Photo 1) (2) Disconnect the connectors, TH3 (white) and TH32 (black), TH33 (yellow) on the controller circuit board in the electrical parts box.
Page 103 OPERATING PROCEDURE PHOTOS/FIGURES Photo 9 7. Removing the 4-way valve coil (21S4), and linear expansion AK24/30/36 valve coil (LEV-A, LEV-B, LEV-C) (1) Remove the service panel. (See Photo 1) High pressure HIC top cover (2) Remove the top panel. (See Photo 1) LEV coil (LEV-C) switch (63H) (3) Remove the electrical parts box.
Page 104 OPERATING PROCEDURE PHOTOS/FIGURES 9. Removing linear expansion valve Photo 10 (1) Remove the service panel. (See Photo 1) AK24/30/36 (2) Remove the top panel. (See Photo 1) (3) Remove the electrical parts box. (See Photo 4) (4) Remove the cover panel front. (Refer to procedure 8) (5) Remove the cover panel rear.
Page 105 OPERATING PROCEDURE PHOTOS/FIGURES 10. Removing the HIC&LEV ASSY Photo 11 (1) Remove the service panel. (See Photo 1) AK24/30/36 (2) Remove the top panel. (See Photo 1) (3) Remove the electrical parts box. (See Photo 4) (4) Remove 2 cover panel front fixing screws (5 × 12) and remove the cover panel front.
Page 106 OPERATING PROCEDURE PHOTOS/FIGURES Photo 12 12. Removing the reactor (DCL) (1) Remove the service panel. (See Photo 1) (2) Remove the top panel. (See Photo 1) (3) Remove the electrical parts box. (See Photo 4) Electrical (4) Remove 6 reactor fixing screws (4 × 10) and remove the parts box reactors.
Page 107 OPERATING PROCEDURE PHOTOS/FIGURES Photo 14 Photo 15 AK24/30/36 Cutting positions AK42/48 Separator Cutting positions Photo 16 14. Removing the power receiver AK24/30/36 (1) Remove the service panel. (See Photo 1) (2) Remove the top panel. (See Photo 1) (3) Remove the electrical parts box. (See Photo 4) (4) Remove the cover panel front.
Page 108 OPERATING PROCEDURE PHOTOS/FIGURES 16. Removing the base heater Photo 17 AK24/30/36 (1) Remove the service panel. (See Photo 1) (2) Remove the top panel. (See Photo 1) Motor support (3) Remove the upper 2 screws (5 × 12) fixing the motor sup- port, the lower 3 screws (5 ×...
Page 109: Remote Controller
REMOTE CONTROLLER 15-1. REMOTE CONTROLLER FUNCTIONS <PAR-42MAAUB> Controller interface The functions of the function buttons change depending on the screen. Refer to the button function guide that appears at the bottom of the LCD for the functions they serve on a given screen. When the system is centrally controlled, the button function guide that corresponds to the locked button will not appear.
Page 110: Room Temperature
Display The main display can be displayed in two different modes: “Full” and “Basic”. The initial setting is “Full”. To switch to the “Basic” mode, change the setting on the Main display setting. (Refer to operation manual included with remote controller.) <Full mode>...
Page 111: Menu Structure
Menu structure Main menu Press the MENU button. Move the cursor to the desired item with the buttons, and press the SELECT button. Operation Vane · Louver · Vent. (Lossnay) High power Comfort Manual vane angle 3D i-see Sensor Timer menu Timer ON/OFF timer Auto-OFF timer...
Page 112 Continue from the previous page. Maintenance menu Error information Filter information Cleaning Auto descending panel Descending operation Descending adjustment Service menu Test run menu Test run Drain pump test run Maintenance information Model name input Serial No. input Dealer information input Initialize maintenance info.
Page 113: Main Menu List
Main menu list Main Setting and display items Setting details menu Operation Vane · Louver · Vent. Use to set the vane angle. (Lossnay) • Select a desired vane setting. Use to turn ON/OFF the louver. • Select a desired setting from "ON" and "OFF." Use to set the amount of ventilation.
Page 114 Setting and display Main menu Setting details items Initial Display Main display Use to switch between "Full" and "Basic" modes for the Main display, and use setting setting to change the background colors of the display to black. Display Make the settings for the remote controller related items as necessary. details Clock: The initial settings are "Yes"...
Page 115: Controller Interface
<PAR-FL32MA> Controller interface Transmission area Transmission indicator Remote controller display Timer indicator *For explanation purposes, all of the items that appear in the display are shown. *All items are displayed when the Reset button is pressed. Operation areas ON/OFF button Temperature setting buttons Fan Speed button (Changes fan speed) Timer Off button...
Page 116 <PAR-SL101A-E> Controller interface Transmission area Remote controller display Set Temperature buttons OFF/ON button Mode button (Changes operation mode) Fan Speed button (Changes fan speed) Airflow button (Changes up/ i-see button* down airflow direction) Timer ON button Menu button Timer OFF button SET/SEND button Weekly timer ON/OFF button* CANCEL button...
Page 117: Error Information
15-2. ERROR INFORMATION When an error occurs, the following screen will appear. Check the error status, stop the operation, and consult your dealer. 1. Check code, error unit, refrigerant address, model name, and serial Error information number will appear. Error code The model name and serial number will appear only if the informa- Error unit Unit#1...
Page 118 Checking the error information Maintenance menu While no errors are occurring, page 2/2 of the error information can be Error information viewed by selecting "Error information" from the Maintenance menu. Filter information Errors cannot be reset from this screen. Cleaning Main menu: RETURN Cursor SELECT...
Page 119: Service Menu
15-3. SERVICE MENU Maintenance password is required 1. Select "Service" from the Main menu, and press the [SELECT] button. Main Main menu *At the main display, the menu button and select "Service" to make the maintenance setting. Service 2. When the Service menu is selected, a window will appear asking for the pass- Service menu word.
Page 120: Test Run Operation
15-4. TEST RUN 15-4-1. PAR-42MAAUB 1. Select "Service" from the Main menu, and press the [SELECT] button. Test run Input maintenance info. Settings Check Select "Test run" with the F1 or F2 button, and press the [SELECT] button. Others : RETURN SELECT MENU RETURN...
Page 121 15-4-2. PAR-FL32MA Measure an impedance between the power supply terminal block on the outdoor unit and ground with a 500 V Megger and check that it is equal to or greater than 1.0 MΩ. TEST RUN Turn on the main power to the unit. TEST RUN Press the button twice continuously.
Page 122 15-5. FUNCTION SETTING 15-5-1. PAR-42MAAUB Settings menu Function setting 1. Select "Service" from the Main menu, and press the [SELECT] button. Select "Setting" from the Service menu, and press the [SELECT] button. Service menu: MENU Select "Function setting", and press the [SELECT] button. SELECT MENU RETURN...
Page 123 15-5-2. PAR-SL97A-E Functions can be selected with the wireless remote controller. Function selection using wireless remote controller is available only for refriger- ant system with wireless function. Refrigerant address cannot be specified by the wireless remote controller. [Flow of function selection procedure] Flow of function selection procedure The flow of the function selection procedure is shown below.
Page 124 15-5-3. PAR-SL101A-E 1. Going to the function select mode Press the button between of 5 seconds. (Start this operation from the status of remote controller display turned off.) [CHECK] is lit and "00" blinks. (Fig. 15-1) Press the button to set the "50". Direct the wireless remote controller toward the receiver of the indoor unit and press the button.
Page 125: Error History
15-6. ERROR HISTORY 1. Select "Service" from the Main menu, and press the [SELECT] button. Test run Input maintenance info. Settings Check Others : RETURN Select "Check" with the F1 or F2 button, and press the [SELECT] button. SELECT MENU RETURN HOLD 2.
Page 126: Self-Diagnosis
15-7. SELF-DIAGNOSIS 15-7-1. PAR-42MAAUB 1. Select "Service" from the Main menu, Diagnosis and press the [SELECT] button. Self check Remote controller check Select "Check" from the Service menu, and press the [SELECT] button. Service menu: MENU Cursor Select "Diagnosis" from the Check menu, and press the [SELECT] button.
Page 127 15-7-2. PAR-SL97A-E When a malfunction occurs to air conditioner, both indoor unit and outdoor unit will stop and operation lamp blinks to inform unusual stop. < Malfunction-diagnosis method at maintenance service> Refrigerant [Procedure] address display 1. Press the CHECK button twice. CHECK •...
Page 128: Remote Controller Check
15-8. REMOTE CONTROLLER CHECK If operations cannot be completed with the remote controller, diagnose the remote controller with this function. 1. Select "Service" from the Main menu, and Diagnosis press the [SELECT] button. Self check Remote controller check Select "Check" from the Service menu, and press the [SELECT] button.
Page 129: Ref.address
15-9. SMOOTH MAINTENANCE Check menu 1. Select "Service" from the Main menu, and press the [SELECT] button. Error history Diagnosis Smooth maintenance Request code Select "Check" with the F1 or F2 button, and press the [SELECT] button. Service menu: MENU Cursor Select "Smooth maintenance"...
Page 130: Request Code
■ Refrigerant address Single refrigerant system Multi refrigerant system (group control) In the case of single refrigerant system, the refrigerant address Up to 16 refrigerant systems (16 outdoor units) can be con- is "00" and no operation is required. nected as a group by 1 remote controller. To check or set the Simultaneous twin, triple units belong to this category refrigerant addresses.
Page 131 HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN ©Copyright 2024 MITSUBISHI ELECTRIC CORPORATION Published: Sep. 2024 No. OCH870 Made in Japan Specifications are subject to change without notice.

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