SERVICE MANUAL Mini VRF System Model No. Outdoor Unit Class U-4LE1E5 U-5LE1E5 U-6LE1E5 Model Name U-4LE1E8 U-5LE1E8 U-6LE1E8 HP = horsepower Indoor Unit Class 4-Way Cassette S-22MU1E5 S-28MU1E5 S-36MU1E5 S-45MU1E5 S-56MU1E5 S-73MU1E5 S-106MU1E5 S-140MU1E5 S-160MU1E5 4-Way Cassette 60×60 S-22MY1E5 S-28MY1E5...
Circuit breaker must be incorporated in the fixed wiring equipment is connected only to a supply with a short- in accordance with the wiring regulations. circuit power Ssc greater than or equal to the value in the table. U-4LE1E5 U-5LE1E5 U-6LE1E5 Circuit breaker 30 A...
Page 3
When Installing… When Servicing • Turn the power OFF at the main power box Select an installation location which is rigid and strong (mains) before opening the unit to check or repair enough to support or hold the unit, and select a location electrical parts and wiring.
Check of Density Limit The standards for minimum room volume are as follows. (1) No partition (shaded portion) The room in which the air conditioner is to be installed requires a design that in the event of refrigerant gas leaking out, its density will not exceed a set limit. The refrigerant (R410A), which is used in the air conditioner, is safe, without the toxicity or combustibility of ammonia, and is not restricted by laws imposed to protect the ozone layer.
Mini VRF SYSTEM Control Functions 1. Introduction OUTDOOR UNIT Mini VRF SYSTEM is a multi system that is connected to a single outdoor unit. The outdoor unit contains an inverter compressor. To operate this system, the below settings must be made at the time of the test run. Table 1-1 At shipment Setting item...
Mini VRF SYSTEM Control Functions 2. Compressor Control 2-1. Compressors Mounted on Outdoor Units Capacity Type Compressors mounted Rotary DC Inverter 2-2. Compressor Stop Rules After a compressor stops, it will not start again for a period of 3 minutes (3 minutes forced OFF). However, this does not apply to the Special Control described later, when operation of the compressor is forcibly stopped as part of a control operation.
Page 10
Mini VRF SYSTEM Control Functions 2. Compressor Control 2-3-1. Roadmap control in cooling mode With this control, the below evaporation temperature control and condensation temperature control are both used. Control is performed according to the following order of priority: Control order of priority Area C >...
Page 11
Mini VRF SYSTEM Control Functions 2. Compressor Control 2-3-2. Roadmap control in heating mode Roadmap control is performed using the below condensation temperature control. Condensation temperature (=Tc) control (Area D) Thermostat OFF 57.5°C 57.4°C Horsepower decrease (Area C) 51.6°C 51.5°C Horsepower increase prohibited (Area B) 49.0°C...
Page 12
Mini VRF SYSTEM Control Functions 2. Compressor Control (2) Primary Current Protection The primary current protection value is divided into the cooling and heating mode. Also, the cooling of single-phase outdoor unit can be divided into two tables according to the outdoor air temperature.
Mini VRF SYSTEM Control Functions 3. Special Controls In addition to ordinary heating and cooling operation, this system also includes the following 4 types of special controls for control of the system as a whole: 3-1. Oil discharge prevention device control 3-2.
Mini VRF SYSTEM Control Functions 3. Special Controls (2) Control in the Heating Mode (2-1) Discharge temperature: less than 30°C Min. 2 minutes 30 seconds to Max. 23 minutes Control hour (Discharge degree-of-overheating: Td* 1 - HPT* 2 > 12 K* 3 ) Compressor Frequency 54Hz Outdoor unit...
Page 15
Mini VRF SYSTEM Control Functions 3. Special Controls 3-2. Reverse Cycle Start Control Reverse cycle start control is performed under the following conditions: • The outdoor unit starts in Heating mode after microcomputer initialization when the power was turned ON. •...
Page 16
Mini VRF SYSTEM Control Functions 3. Special Controls 3-4-3. Frost detection Frost is not detected at the outdoor unit heat exchanger for 5 minutes after operation starts. Frost is detected when either Condition 1 or 2 below is met. Heat exchange liquid temperature °C Condition 1: Defrosting operation (The end temperature is...
4. Other Control Mini VRF SYSTEM Control Functions 5. Operation of Solenoid Valves 6. Outdoor Unit Electronic Control Valve (Motor Valve) control [MOV1] 4. Other Control 4-1. Indoor Unit Self-Separator Oil Recovery Control Refer to the indoor unit special control item. 5.
Mini VRF SYSTEM Control Functions 7. Outdoor Fan Control 7-1. Outdoor Fan (Min.Fan Mode and Max.Fan Mode) These outdoor units utilize a DC fan motor that can be controlled using a maximum of 15 increments (15 fan modes). Outdoor unit Min.
Mini VRF SYSTEM Control Functions 8. Indoor Unit Electronic Control Valve (Motor Valve) Control INDOOR UNIT 8-1. During Normal Control During Cooling mode operation MOV position (pulses) Outdoor unit operating Outdoor unit stopped Stop 20 pulses 20 pulses 20 pulses 20 pulses Thermostat OFF 20 pulses...
Mini VRF SYSTEM 8. Indoor Unit Electronic Control Valve (Motor Valve) Control Control Functions 9. Indoor Special Control 8-2. During Special Control Control type Operating mode Target indoor units Electronic control valve position (pulses) Fixed pulses for cooling, corresponding to Cooling All indoor units the indoor unit capacity...
Page 21
Mini VRF SYSTEM Control Functions 9. Indoor Special Control 9-3. Indoor Fan Speed Control CCU intervenes in fan control of the indoor unit according to the state at the operating mode below. The priority order of fan control by CCU is higher than that of indoor unit’s. 9-3-1.
Page 22
Mini VRF SYSTEM Control Functions 9. Indoor Special Control 9-4. Drain Pump control CCU intervenes in drain pump control of the indoor unit according to the setting in EEPROM in the outdoor unit. The drain pump operates from CCU control at the following condition. - DP counter * The DP counter counts each oil recovery control.
Page 23
Mini VRF SYSTEM Control Functions 9. Indoor Special Control 9-5. Discharge air temperature control For Type F1, M1, E1 indoor units, discharge air temperature is controlled from the CCU to prevent condensation on duct surface in cooling operation. The CCU monitors and adjusts To of indoor unit.
Mini VRF SYSTEM 10. Discharge Gas Temperature Control Functions 11. Current Protection 10-1. Discharge Gas Temperature Protection Alarm The compressor upper-limit discharge temperature is 106°C. If the discharge temperature reaches 106°C, then the compressor stops. If the discharge temperature reaches 106°C 4 times repeatedly after restart, an alarm occurs.
11. Current Protection Mini VRF SYSTEM Control Functions 12. Pressure Sensor Failure 13. 4-Way Valve Failure [L18] 11-2. Inverter Compressor Alarm Description Occurs when overcurrent (32.5 A) is detected during normal operation. Occurs when a missing phase or overcurrent (48 A) is detected when the inverter compressor starts.
Mini VRF SYSTEM Control Functions 14. Servicing and Maintenance Functions The below functions are available, and are selected by the outdoor unit EEPROM settings. 14-1. Outdoor Unit Noise Countermeasures (outdoor Quiet mode function) This function reduces the operating noise to lessen the noise produced by the outdoor unit. When this mode is selected, noise reduction is given priority during operation, and the outdoor fan mode and compressor operating frequency are restricted (to approximately 80% of capacity).
Mini VRF SYSTEM Control Functions 15. Demand Control 15-1. Demand Control Demand terminal block (optional CZ-CAPDC3) or Seri-Para I/O unit (optional CZ-CAPDC2) must be connected in order to perform demand control. The current limitation values can be set by changing either contact. Demand terminal block Seri-Para I/O unit Control...
Mini VRF SYSTEM Outdoor Unit Repair Procedures Contents 2. OUTDOOR UNIT REPAIR PROCEDURES Layout Diagram: Sensors and solenoid valves ....... . . 2-2 1.
Mini VRF SYSTEM Outdoor Unit Repair Procedures Layout Diagram: Sensors and solenoid valves (4-way valve) (suction thermistor) (electronic motor-operated valve) Front side Front side (condenser 1 thermistor) 2 - 2...
Mini VRF SYSTEM Outdoor Unit Repair Procedures 1. Removing Panels (1) Front panel removal (Fig. 2-1) • Remove the front panel (remove 3 screws). (2) Cover A removal (Fig. 2- 1) • Remove the cover A (remove 1 screw). Front panel Cover A Fig.
Mini VRF SYSTEM Outdoor Unit Repair Procedures 2. Discharging Oil in Compressor Recover the refrigerant in the outdoor unit following the procedures in “3. Recovering Refrigerant.” Remove the compressor and discharge the oil in it. Refer to “8. Compressor” for detailed procedures. 2-1.
Mini VRF SYSTEM Outdoor Unit Repair Procedures 3. Recovering Refrigerant The following equipment and tools are required: Jumper wire with clips, adjustable wrench, set of manifold gauge valves specially designed for refrigerant R410A only, vacuum pump, refrigerant recovery unit, pre-purged refrigerant cylinder for recovery (air already evacuated), and hex wrench (4 mm for liquid tube and 5 mm for gas tube).
Page 34
Mini VRF SYSTEM Outdoor Unit Repair Procedures 3. Recovering Refrigerant 3-2. Refrigerant Recovery Procedures (Indoor Unit) The flowchart below shows the refrigerant recovery procedures you must follow when replacing or repairing the indoor unit due to trouble in the refrigerant circuit. START 3-2-1.
Page 35
Mini VRF SYSTEM Outdoor Unit Repair Procedures 3. Recovering Refrigerant 3-2-1. Cooling operation (for all units) Short-circuit the TEST pin (CN-TEST) on the outdoor control PCB. Let the unit operate for a while, then check if it is running in Cooling mode or Heating mode by touching the gas line with your finger.
Page 36
Mini VRF SYSTEM Outdoor Unit Repair Procedures 3. Recovering Refrigerant Manifold gauge Refrigerant recovery unit Refrigerant Ball valve recovery cylinder (field supply) Gas tube Service port Indoor unit Outdoor unit Liquid tube Fig. 2-4 2 - 8...
Page 37
Mini VRF SYSTEM Outdoor Unit Repair Procedures 3. Recovering Refrigerant 3-2-3. Refrigerant recovery procedures (B): for indoor unit with no ball valve Refrigerant in all indoor units and the refrigerant tubing circuit must be pumped into the outdoor unit (referred to as “pump down”).
Mini VRF SYSTEM Outdoor Unit Repair Procedures 4. Checking for Leakage After Repair 4-1. Pressure Check for Leakage of Outdoor Unit After completing repair of the outdoor unit, carry out the following leakage check. Check that all service valves for gas line, and liquid line in the repaired outdoor unit are fully closed. Connect the manifold gauge valves to the high- and low-pressure sensor outlets of the outdoor unit.
Mini VRF SYSTEM Outdoor Unit Repair Procedures 5. Evacuating System This procedure is carried out to ensure there is no remaining refrigerant or other gases (nitrogen, etc.) in the repaired outdoor unit and tubing. 5-1. Evacuating Repaired Outdoor Unit Check that each service valve of the gas line, and the liquid line in the outdoor unit are fully closed. * If the AP pins (CN-AP) on the outdoor control PCB have already been short-circuited, steps (2) and (5) are not necessary.
Mini VRF SYSTEM Outdoor Unit Repair Procedures 6. Pumping Out Refrigerant from Outdoor Unit Required equipment and tools: Jumper wire with clips, adjustable wrench, set of manifold gauge valves, vacuum pump, refrigerant recovery unit, pre-purged refrigerant cylinder for recovery, and hex wrench (4 mm for liquid tube and 5 mm for gas tube).
Page 41
Mini VRF SYSTEM Outdoor Unit Repair Procedures 6. Pumping Out Refrigerant from Outdoor Unit NOTE To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit. Low-pressure outlet port (For ø7.94 mm connector) Manifold gauge Connect from here to refrigerant recovery unit...
Mini VRF SYSTEM Outdoor Unit Repair Procedures 7. Compressor 7-1. Compressor Trouble Diagnosis and Check Methods Generally, compressor failures can be classified into the following categories. Mechanical trouble (A) Locking (intrusion of foreign objects, galling, etc.) (B) Pressure rise failure (damaged valve, seal, bearing, or other component) (C) Noise (damaged stator, rotor, valve, or other component) Electrical trouble (A) Coil burning...
Page 43
Mini VRF SYSTEM Outdoor Unit Repair Procedures 7. Compressor The connecting port includes a Schrader-type, push-to-release valve. CAUTION When disconnecting the hose, pressure will be applied from the refrigerant in the outdoor unit. Follow the instructions in “7-3. Dry Core Cleaning” and perform dry core cleaning of the outdoor unit that failed. 7-3.
Page 44
Mini VRF SYSTEM Outdoor Unit Repair Procedures 7. Compressor (18) Remove dry cores. Connect the tube that runs Outdoor unit from the liquid tube valve to the ball valve. Liquid tube service port (19) At the outdoor unit where dry cores were removed, pressurize with 3.80 MPa of nitrogen from the liquid tube service port and check for leaks.
Mini VRF SYSTEM 7. Compressor Outdoor Unit Repair Procedures 8. High Pressure Sensor Installation Prepare for installation. • Remove the rubber stopper and tube cap (welded) from the new compressor. Install the crankcase heater onto the compressor. Place the cushioning rubber in the designated positions on the compressor. (There are 3 pieces for an inverter compressor.) Set the new compressor into the unit.
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 1. Overview [Service Checker Section] OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER (CZ-RTC2) for MINI VRF SYSTEM ■ About the outdoor unit maintenance remote controller The outdoor unit utilizes nonvolatile memory (EEPROM) on its PCB. This allows EEPROM data to replace the setting switches that were present on previous PCBs.
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 2. Functions ■ Functions on the ordinary display (1) Functions: Button operations can be used to perform the following functions. • Start/stop of all indoor units • Switching between cooling and heating •...
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 3. Ordinary Display Controls and Functions ■ Functions on the ordinary display • Connect the special service checker wiring to the outdoor unit PCB. The connection is shown in the figure below. Outdoor unit PCB RC (3P, BLU) PCB connector (3P, BLU)
Page 51
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 3. Ordinary Display Controls and Functions ● All units start/stop (Fig. 3-1) <Operation> (ON/OFF operation) button can be used to start and stop all the indoor units. • The LED illuminates if any indoor units is operating. •...
Page 52
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 3. Ordinary Display Controls and Functions ■ Display (functions) • Use the temperature setting buttons to change the item code. Item code Item Remarks ➀ Outdoor unit alarm ➁ Alarm code display No.
Page 53
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 3. Ordinary Display Controls and Functions ■ XX-YY R.C. (Fig. 3-3) Displays the outdoor unit sub-bus address which is currently selected. XX = Outdoor system address on main bus line (1 – 30) YY = Outdoor unit sub-bus address.
Page 54
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 3. Ordinary Display Controls and Functions ■ Concerning the 7-segment, 4-digit display remote controller timer display The unit Nos. of connected units are indicated by four 7-segment digits ( ) and a colon. ●...
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 4. Monitoring Operations Display the indoor unit and outdoor unit sensor temperatures. <Operating procedure> ➀ Press and hold the (CHECK) button and buttons simultaneously for 4 seconds or longer to engage temperature monitor mode. During temperature monitoring, is illuminates.
Page 56
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 4. Monitoring Operations Display of unit No. 1 (main unit) Indoor unit intake temp. °C Indoor unit heat exchanger temp. (E1) °C Not used °C Indoor unit heat exchanger temp. (E3) °C Indoor unit Discharge air temp.
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 5. Outdoor Unit Alarm History Monitor • Displays outdoor unit alarms only. • Check the indoor unit alarm histories separately using the indoor unit remote controllers or other control device. <Operating procedure> ➀...
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 6. Mode Settings Setting mode 1 Display of first 4 digits <Operating procedure> Press and hold the (CHECK) button and (VENTILATION) button simultaneously for 4 seconds or longer. Press the temperature setting buttons to change the item code.
Page 59
Mini VRF SYSTEM Outdoor Unit Maintenance Remote Controller 6. Mode Settings ■ Setting mode 2 <Operating procedure> ➀ Press and hold the (CHECK) button, button, and button simultaneously for 4 seconds or longer. ➁ Press the temperature setting buttons to change the item code.
Mini VRF SYSTEM Remote Controller Functions 1. Simple Settings Function • This allows the filter lifetime, operating mode [Remote Controller Functions Section] priority change, central control address, and other settings to be made for an individual or group- control indoor unit to which the remote controller used for simple settings is connected.
Page 63
Mini VRF SYSTEM Remote Controller Functions 1. Simple Settings Function List of Simple Setting Items Setting data Item code Item Description 0000 Not displayed 0001 150 hours 0002 2,500 hours Filter sign ON time (fi tlter life time) 0003 5,000 hours 0004 10,000 hours 0005...
Page 64
Mini VRF SYSTEM Remote Controller Functions 1. Simple Settings Function Simple setting items Item code Item Description Filter sign ON time setting Changes the indoor unit fi lter lifetime when a high-performance fi lter or other (fi lter lifetime) optional product is installed. Reduces the fi...
Page 65
Mini VRF SYSTEM Remote Controller Functions 1. Simple Settings Function Item code Item Description Set when using a central control device. Central control address Used when setting the central control address manually from the remote controller. Operating mode priority change Note (1) NOTE (1) Explanation of operation mode priority change...
Page 66
Mini VRF SYSTEM Mini VRF SYSTEM Remote Controller Functions Remote Controller Functions 1. Simple Settings Function 1. Simple Settings Function When the operating mode at the priority remote controller is changed, the operating modes of other remote controllers change as shown below. Mode change at priority remote controller Operating modes at other remote controllers Current mode New mode...
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function • This allows the system address, indoor unit address, and other settings to be made for the individual or group-control indoor unit to which the remote controller used for detailed settings is connected.
Page 68
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Setting the Flap Separately (When setting the CZ-RTC2) Press the timer time buttons to select 1) The 4-air outlet flap can be adjusted separately during the desired setting data. operation. When not adjusted separately, all flaps operate Flap position in the same manner.
Page 69
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function List of Detailed Setting Items Setting data Item code Item Description Description Description 4-Way Casstte (60×60) 0001 0002 2-WAY Cassette (L1) 0003 1-Way Cassette (D1) (U1, Y1) Low Silhouette Ducted (F1) High Static Pressure Type 0005...
Page 70
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Setting data Item code Item Description 0000 5 minutes (1B) Forced thermostat ON time 0001 4 minutes –010 –10°C –009 –9°C Cooling discharge –008 –8°C temperature shift 0010 10°C –010 –10°C –009 –9°C...
Page 71
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Setting data Item code Item Description 0000 No forced operation 0001 Forced operation for 1 minute Automatic drain pump operation 0060 Continuous operation 0000 None Ventilation fan operation 0001 Ventilation fan operated by remote controller. Wired remote controller 0000 Not used.
Page 72
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Setting data Item code Item Description DC fan tap operating Purpose mode 0000 Standard Standard (setting at shipment) High ceiling use High ceiling setting 1 (with standard panel) 0001 For low Ultra long-life fi...
Page 73
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item Description Unit type Set when the indoor unit EEPROM memory is replaced during servicing. Indoor unit capacity System (outdoor unit) address These are not set at the time of shipping from the factory. These must be set after installation if automatic address setting is not Indoor unit address performed.
Page 74
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item Description 1F (Upper limit) Cooling 20 (Lower limit) 21 (Upper limit) This setting changes the temperature range (upper limit and lower Heating 22 (Lower limit) Change to the remote limit) which is set from the remote controller or central control device.
Page 75
Mini VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function (Continued from previous page) Item code Item Description Heat exchanger temperature for The heat exchanger temperature control point for prevention of cold air cold air discharge discharge during heating operation can be changed. The indoor unit PCB optional output for the fan can be switched Fan output switching according to the purpose of use.
Page 76
Mini VRF SYSTEM Mini VRF SYSTEM Remote Controller Functions Remote Controller Functions 2. Detailed Settings Function 2. Detailed Settings Function Selecting the DC fan motor tap (when setting from the PCB) 4-Way Cassette type <Procedure> Stop the system before performing these steps. Open the electrical component box cover, then check the indoor unit control PCB.
Mini VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions • The remote controller includes a number of servicing functions. Use these as needed for test runs and inspections. List of Servicing Functions Functions Description Button operation Reset operation Unit status Operation with Press and hold the...
Page 78
Mini VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions Test Run Function Operates the unit with the thermostat forced ON. <Procedure> ➀ Press and hold the button for 4 seconds or longer. ➁ “Test” appears on the remote controller LCD display (Fig.
Page 79
Mini VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions Sensor temperature display function (displayed both when unit is running and stopped) Use the following check procedure to display the sensor temperatures from the remote controller, indoor unit, and outdoor unit sensors on the remote controller display.
Page 80
Mini VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions Sensor Temperature Relationship Table Sensor Sensor Location where Sensor type Sensor type address address sensor is installed Indoor unit heat exchanger Room temp. *1 temp. (E3) Remote controller Discharge air temp. temp.
Mini VRF SYSTEM Trouble Diagnosis 1. Contents of Remote Controller Switch Alarm Display Blinking: OFF: Wired Wireless remote remote controller control receiver display display Possible cause of malfunction Remote controller is Error in receiving serial communication signal Serial Operating lamp detecting error signal from (Signal from main indoor unit in case of group control) <E01>...
Page 83
Mini VRF SYSTEM Trouble Diagnosis 1. Contents of Remote Controller Switch Alarm Display Blinking: OFF: Wired Wireless remote remote controller control receiver display display Possible cause of malfunction Incorrect discharge temperature (Comp.) Activation of Protective device in outdoor protective unit is activated. High-pressure switch device Power supply circuit failure, missing-phase detection...
Mini VRF SYSTEM Trouble Diagnosis 2. Outdoor Unit Control Panel LED Display : ON : Blinking : OFF ) LED1 LED2 Display meaning D302 D303 After the power is turned ON (and automatic address setting is not in progress), no communica- tion with the indoor units in that system is possible.
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes Alarms for outdoor units Alarm Alarm Meaning Code Remote Controller Reception Error Remote Controller Transmission Error Error in Indoor Unit Receiving Signal from Remote Controller (central) Error in Indoor Unit Receiving Signal from the Outdoor unit Error in Indoor Unit Transmitting Signal to the Outdoor Unit Error in the Outdoor Unit Receiving Signal from the Indoor Unit Error in Outdoor Unit Transmitting Signal to the Indoor Unit...
Page 86
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes Checks Prior to Auto Address Setting If an outdoor unit displays an alarm, conduct this process after diagnosing the problem. 1 Auto Address Is the power of the indoor unit(s) and outdoor unit(s) on? Power on Indoor/ Has the wiring of the indoor/outdoor control line been completed?
Page 87
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E01 Remote Controller Reception Error (When indoor unit(s) are connected) Error Detection Method It is judged an error if no self-addressed communication is sent to the remote controller in a 3-minute period. When a remote controller is set to sub remote controller.
Page 88
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes OPTION CHK Pin TEST Pin DC Motor Model Indoor Unit Control Board CHK Pin OPTION AC Motor Model Indoor Unit Control Board 5 - 8...
Page 89
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E02 Remote Controller Transmission Error Error Detection Method When the remote controller itself cannot transmit. Or when it cannot receive the signal it transmitted itself, or when they are different and judged an error.
Page 90
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E03 Error in Indoor Unit Receiving Signal from Remote Controller (central) (When indoor unit(s) are connected) Error Detection Method It is judged an error when there is no communication from any remote controller (collectively) in a 3-minute period or if there is no communication from the central device in a 15-minute period.
Page 91
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes OPTION OPTION DC Motor Model Indoor unit Control PC Board AC Motor Model Indoor unit Control PC Board 5 - 11...
Page 92
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E04 Error in Indoor Unit Receiving Signal from the Outdoor unit Error Detection Method When there is no communication within a 3-minute period from the outdoor unit. Or, judged an error when no reply comes from the outdoor unit.
Page 93
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes • The ‘/’ in the table indicates the DC motor’s indoor unit board/AC motor’s indoor unit board. • There is no TEST pin on the AC motor’s indoor unit board. •...
Page 94
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E05 Error in Indoor Unit Transmitting Signal to the Outdoor Unit Error Detection Method It is judged an error when a unit itself cannot receive a signal that it has sent. •...
Page 95
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E06 Error in the Outdoor Unit Receiving Signal from the Indoor Unit (When indoor unit(s) are connected) Error Detection Method It is judged an error when there is no transmission (reply) from the indoor unit to the outdoor unit for a period of three minutes. The indoor unit is not turned on.
Page 96
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E07 Error in Outdoor Unit Transmitting Signal to the Indoor Unit Error Detection Method It is judged an error when a unit itself cannot receive (discrepancy) a signal within a 3-minute period that it had sent. •...
Page 97
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E08 Duplicate Indoor Unit Address Settings Error Error Detection Method It is judged an error if the addresses of indoor units are duplicated. • The indoor unit address settings are duplicated in the remote control detailed settings mode. •...
Page 98
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E09 More Than One Remote Controller Set to Main Error Error Detection Method It is judged an error when more than one remote controller in a remote control group is set as the main remote controller. Forgot to set one remote controller to sub in a 2-remote control group.
Page 99
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E12 Start of Auto Address Setting Prohibited Due to Auto Address Setting Being in Progress Error Detection Method It is judged an error if a command to start auto address setting comes from another controller during auto address setting. This occurs in a system that has more than one outdoor unit and operating lines among the indoor/outdoor units •...
Page 100
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E15 Auto-Address Alarm (not enough units) (When indoor unit(s) are connected) Error Detection Method It is judged an error not enough indoor units reply to communications and this is determined from the number of indoor units specified with the outdoor unit.
Page 101
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E16 Auto-Address Alarm (too many units) Error Detection Method It is judged an error when there are too many indoor units that reply to communications and this is determined from the number of indoor units specified with the outdoor unit.
Page 102
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E18 Faulty Communication in Group Control Wiring Error Detection Method When the main remote controller cannot communicate with a sub remote controller in the remote control group. It is judged an error if a sub remote controller in a remote control group fails to communicate with the main remote controller for a period of three minutes.
Page 103
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E20 No Indoor Units Error Error Detection Method It is judged an error if an indoor unit cannot be recognized at the start of auto address setting or when the outdoor unit is turned The address(es) of indoor unit(s) are not assigned correctly.
Page 104
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes E30 Outdoor Unit Serial Transmission Error (Transmission from an outdoor unit faulty.) Error Detection Method Outdoor unit unable to read and confirm its own transmission data with the board of the outdoor unit. •...
Page 105
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F04 Compressor Discharge Temperature Sensor Error Error Detection Method It is judged an error based on the criteria listed below. Open circuit or Short circuit • • When compressor stopped temporally, even after 20 minutes passed, over 103°C of discharge temperature is detected. •...
Page 106
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F07 Heat Exchanger Inlet Temperature Sensor (C1) Error Error Detection Method It is judged an error when open circuit or short circuit. Error Diagnosis 1 Sensor Sensor connector is connected to PC board properly. Reconnect and check Replace sensor Resistance between sockets is infinity or 0 ohm.
Page 107
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F08 Outdoor Air Temperature Sensor (TO) Error Error Detection Method It is judged an error when open circuit or short circuit. Error Diagnosis 1 Sensor Sensor connector is connected to PC board properly. Reconnect and check Replace sensor Resistance between sockets is infinity or 0 ohm.
Page 108
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F12 Compressor Intake Temperature Sensor (TS) Error Error Detection Method It is judged an error when open circuit or short circuit. Error Diagnosis 1 Sensor Sensor connector is connected to PC board properly. Reconnect and check Replace sensor Resistance between sockets is infinity or 0 ohm.
Page 109
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F16 High Pressure Sensor Error Error Detection Method It is judged an error based on the criteria listed below. Cooling: Status of lower 5°C saturated temperature under the detect pressure compared to the outdoor heat exchanger •...
Page 110
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes F31 Outdoor Unit Nonvolatile Memory (EEPROM) Error Error Detection Method It is judged an error based on the criteria listed below. When power initially turned ON for the first time, nonvolatile memory (EEPROM) is not installed. •...
Page 111
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes H01 Primary Current (Input) Detect of Overcurrent Error Detection Method • Primary current effective value detected overcurrent (trip current value). Trip current value hp = horse power Trip current value hp = horse power Single-phase model 3-phase model...
Page 112
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes H02 PAM Error Error Detection Method • Error is detected by over-voltage and overcurrent of DC side. Error Diagnosis Check power supply 1 Power Not satisfied with + 10% rated supply voltage supply* Check power supply Extreme voltage fluctuations...
Page 113
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes H03 Compressor CT Sensor (Current Sensor) Unplugged Error Detection Method It is judged an error based on the criteria listed below. • If 18A or greater is detected when the compressor is stopped (alarm triggered even if the connector is unplugged). •...
Page 114
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes H31 HIC Error Error Detection Method It is judged an error if the computer detects an error signal from the HIC. An error signal is issued by the HIC if abnormal heat occurs inside the HIC or if there is an overcurrent. However, it is judged an error in the same way if the signal line from the HIC is not connected properly or opened.
Page 115
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes NU W (for Single-phase outdoor unit HIC PC board) (for 3-phase outdoor unit HIC PC board) CN-PRY1 (for 3-phase outdoor unit CR PC board) 5 - 35...
Page 116
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes L04 Duplicated Setting of Outdoor System Address Error Error Detection Method It is judged an error when the identical self-address communication on the indoor and outdoor wirings is received over 5 times within 3 minutes.
Page 117
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes L10 Outdoor Unit Capacity Not Yet Setup Error Error Detection Method It is judged an error when outdoor unit capacity not yet setup or systematically unauthorized setting. Error Diagnosis 1 Check the control Was EEPROM replaced when PC board was replaced?
Page 118
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes L18 4-way valve operation failure Error Detection Method It is judged an error when during heating operation (Comp. ON), the highest detected temperature at an outdoor unit heat exchanger (C1) was 20°C or more above the outdoor air temperature (Air Temp.) continuously for 5 minutes or longer, or the detected suction temperature (SCT) was 20°C or more above the outdoor air temperature continuously for 5 minutes or longer.
Page 119
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P03 Compressor Discharge Temperature Error Error Detection Method • When the discharge temperature is over 106°C. Error Diagnosis Additional 1 Adjustment refrigerant charge Not additional refrigerant charged refrigerant charge Adjust the refrigerant amount Tends to have insufficient refrigerant charge in the system.
Page 120
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P04 Actuation of High Pressure Switch Error Detection Method It is judged an error if the internal circuit of the high pressure switch is dead. The electronic circuitry of the high pressure switch is cut off if the pressure at the pressure sensor port of the high pressure switch reaches 3.80 MPa.
Page 121
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes 3 Problem Prevent air short The intake temperature (ambient temperature) of the indoor unit is around the circuit above 36°C. heat exchanger Clean the filter The filter of the indoor unit is clogged. Replace the indoor fan (motor) The fan of the indoor unit is broken or the fan motor is faulty.
Page 122
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P05 Power Supply Error Error Detection Method • Instantaneous blackout • Zero-cross (waveform input of power supply) error • DC voltage charge failure Error Diagnosis Note : The work involved in diagnosing each of the items is extremely dangerous, so turn the power off at the breaker before performing the tests.
Page 123
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P13 Forgot-to-open Valve Alarm Error Detection Method Detection is performed only in the test run. When once detected or the test run finished without any error, the second detection will not be done. In case of forgetting to open a valve, P04 (high-pressure switch operational alarm) is occasionally preceded due to the following conditions.
Page 124
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P14 O Sensor Error Detection Method • It is judged an error whenever the outdoor unit receives the signal “O Alarm Occurred” from the indoor unit. • With the indoor unit's EEPROM setting (item code 0B) set to 0001, the EXCT input was shorted. Error Diagnosis 1 System Is an O...
Page 125
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P16 Overcurrent of Inverter Compressor Meaning of Alarm • Secondary current effective value detected the overcurrent (trip current value). Single-phase model : Trip current = 24.0 A 3-phase model : Trip current = 18.0 A •...
Page 126
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes 4 Check the Take measures Outdoor air intake temperature is high. situation Correct May be caused by poor outdoor unit air flow (dirty or clogged heat exchanger, blocked discharge port, etc.) Prevent air short Air short circuit has occurred.
Page 127
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes 9 Check the See what happens. Replace the HIC PC board and operate the unit. (Apply putty and HIC PC screws must not be loose) Does it operate normally? 10-1 boards 10 Check the...
Page 128
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P22 Outdoor Fan Motor Error Error Detection Method • It is judged an error when the outdoor fan motor's rotating signal cannot be detected normally. Error Diagnosis 1 Wiring Are the connectors “CN-FMA”, “CN-FMB”, “CN-FM1”, and “CN-FM2”...
Page 129
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes P29 INV Compressor Start-up Failed (including lock) Due to INV Compressor Wiring Open Phase, Faulty DCCT, etc. Error Detection Method • Abnormal current is detected at DCCT before start-up. •...
Page 130
Mini VRF SYSTEM Trouble Diagnosis 3. Mini VRF System Alarm Codes Single-phase outdoor unit HIC board 4WAY Valve (CN-20S) Crankcase heater (CN-CH) CN-VDC- CN-VDC+ 3-phase outdoor unit HIC board 4WAY Valve (CN-20S) Crankcase heater (CN-CH) PIN2 PIN1 (VDC-) (VDC+) 5 - 50...
Mini VRF SYSTEM Trouble Diagnosis 4. Inspection of Parts (Outdoor Unit) Electronic control valve (MOV1) MOV1: Measure the voltage between plug pin 5 and pins 1 through 4 at the CN-MOV1 connector (5P, white) on the outdoor unit control PCB. (Because of the pulse output, a simplified measurement method is used. Set the tester to the 12 V range;...
Mini VRF SYSTEM 5. Symptom: Thermostat in OFF continues or Trouble Diagnosis cycles OFF & ON too frequently How to detect abnormality • Abnormality does not occur. Protective function can be checked when the outdoor maintenance remote controller is connected. Error Diagnosis Adjust setting Indoor control...