SERVICE MANUAL 3WAY VRF SYSTEM U-72MF1U9 U-72MF1U9E * U-96MF1U9 U-96MF1U9E * Model No. Outdoor Units Class Model Name 72 U-72MF1U9 U-72MF1U9E* 96 U-96MF1U9 U-96MF1U9E* Refrigerant R410A is used in the outdoor units. * Salt-Air Damage Resistant Specifications.
thin aluminum fins on the air conditioner can cut your fingers. IMPORTANT! Please Read Before Starting When Installing… This air conditioning system meets strict safety and operating standards. As the installer or service person, it is an important part of your job to install or service the system so it operates safely and efficiently. For safe installation and trouble-free operation, you must: Carefully read this instruction booklet before beginning.
When Servicing CAUTION • Turn the power OFF at the main power box (mains) before opening the unit to check or repair electrical parts and wiring. • Keep your fingers and clothing away from any moving parts. • Clean up the site after you finish, remembering to check that no metal scraps or bits of wiring have been left inside the unit being serviced. • Do not clean inside the indoor and WARNING outdoor units by users. Engage authorized dealer or specialist for cleaning.
Precautions for Installation Using New Refrigerant 1. Care regarding tubing 1-1. Process tubing Material: Use C1220 phosphorous deoxidized copper specified in JIS H3300 “Copper and Copper Alloy Seamless Pipes and Tubes.” For tubes of ø7/8" (ø22.22 mm) or larger, use C1220 T-1/2H material or H material, and do not bend the tubes. Tubing size: Be sure to use the sizes indicated in the table below. Use a tube cutter when cutting the tubing, and be sure to remove any flash.
3-2. Use R410A exclusive cylinder only. Valve Single-outlet valve (with siphon tube) Liquid refrigerant should be recharged with the cylinder standing on end as shown. Liquid New refrigerant R410A cannot be used for earlier models 1. Compressor specifications are different. If recharging a R22 or R407C compressor with R410A, durability will significantly decrease since some of the materials used for compressor parts are different. 2. Existing tubing cannot be used (especially R22).
— CONTENTS — Section 1: CONTROL FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. Section 2: OUTDOOR UNIT REPAIR PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Section 3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section 4. REMOTE CONTROLLER FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 1. 2. 3. Section 5. Simple Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Detailed Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-WAY VRF SYSTEM Control Functions Contents 1. CONTROL FUNCTIONS 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 2. Selecting Outdoor Unit for Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 3. Compressor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 4. Special Controls . . . . . . . . . . . . . . . . . . .
3-WAY VRF SYSTEM Control Functions 1. Introduction The 3-WAY VRF is a system that allows multiple outdoor units to be connected. The outdoor units all contain inverter compressors, and the system does not utilize the sub units that were used in earlier systems. The outdoor unit where the unit No. is set to “1” includes the CCU (command controller unit) functions that are used to control the entire system. As a result, the system will not operate if no outdoor unit has been set as unit No. “1.
3-WAY VRF SYSTEM Control Functions 2. Selecting an Outdoor Unit for Operation 2-1. Outdoor Unit Operating Rules Because in this system all outdoor units contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation. Therefore there is no order of priority for the outdoor units. However, it is possible to operate the outdoor units in sequence, beginning with unit No.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control 3-1. Compressors Mounted in the Outdoor Units [U-72MF1U9, U-72MF1U9E, U-96MF1U9, U-96MF1U9E] Capacity Installed Compressor 1 compressor Compressor 2 72 96 Rotary DC Inverter DC Inverter Scroll – 5 hp hp = horsepower 1 Constant speed INV INV Compressor 1 Compressor 2 Type 72 Compressor 1 Type 96 3-2.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control 3-3. Compressor Capacity Control The compressor operating conditions vary depending on the indoor unit operating conditions and on the effects of indoor heat load, outside temperature, and other factors. Unit No. 1 (CCU) calculates the required capacity according to these operating conditions, and allocates the capacity requirement among the outdoor units, according to the compressor start/stop rules.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control 3-6-1. Evaporation Temperature (Te) Control: Control of Indoor Units Operating in Cooling Mode 60.8 ˚F Horsepower increase 51.9 permitted Area A 53.6 51.8 51.8 1 Horsepower increase permitted 41.1 41.0 35.6 45.5 Area AB 41.0 Horsepower increase prohibited 35.4 Horsepower decrease Area B 35.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control 3-6-2. Condensation Temperature (Tc) Control: Control when there are indoor units operating in Heating mode PX = 125.6 ˚F Thermostat OFF PX Area D –0.1 Horsepower decrease Area C 118.5 118.4 118.4 Horsepower increase prohibited 1 Area B 116.6 116.6 116.4 113.0 112.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control Compressor Control Table Low Condensation Temp. [Tc] Evaporation Temp. [Te] High A A UP B slow_UP C D not_UP Target STOP DOWN not_UP C Low 1 High B Evaporation temperature (Te) and condensation temperature (Tc) areas A, B, C, and D are the same as for evaporation temperature control and condensation temperature control.
3-WAY VRF SYSTEM Control Functions 3. Compressor Control (3) Increasing/decreasing the heat exchanger capacity (when the outdoor unit heat exchanger is functioning as an evaporator) • Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are low This occurs when the cooling capacity (heat intake) is high and the heating capacity (heat discharge) is low.
3-WAY VRF SYSTEM Control Functions 4. Special Controls (2) Current protection Inverter compressor current control is composed of primary current control and secondary current control. Current protection control for the inverter compressor is performed by self-protection in the inverter circuit, and does not increase or decrease the compressor capacity. 1 Primary current Secondary current – 75 or (302 °F) Thermostat OFF – 48 or above Thermostat OFF 26.5 25 ~ 32.
3-WAY VRF SYSTEM Control Functions 4. Special Controls In addition to ordinary heating and cooling operation, this system also includes the following 3 types of special controls for control of the system as a whole. 1. Tube refrigerant recovery control 2. System refrigerant oil recovery control 3. Defrost control 4-1.
3-WAY VRF SYSTEM Control Functions 4. Special Controls 4-2-3. Flow of system refrigerant oil recovery control (1) Simplified flow of system refrigerant oil recovery control System refrigerant oil recovery control follows this flow: Normal operation → 3-minute stop (May stop for 6 minutes.) → System refrigerant oil recovery control (Max.
3-WAY VRF SYSTEM Control Functions 4. Special Controls 4-3-3. Frost detection (A) Frost detection does not occur for 5 minutes after operation starts. (B) Frost is detected when either condition 1 or 2 below is met. Condition 1: L2 line or below is detected twice, each time continuously for 4 minutes, when the compressor is operating. Condition 2: L1 line or below is detected for a total of 60 minutes when the compressor is operating. Heat exchange liquid temperature ˚F Defrosting operation 42.
3-WAY VRF SYSTEM Control Functions 4. Special Controls 4-3-6. Outdoor unit cycle defrost 1 Outdoor unit cycle defrost is performed in systems where 2 outdoor units are connected to the refrigerant system. (1) Description of outdoor unit cycle defrost With this defrost method, when 1 outdoor unit operates in defrost mode (heat exchanger operating as a condenser), another outdoor unit operates as an evaporator in the same way as in ordinary heating mode.
3-WAY VRF SYSTEM Control Functions 4. Special Controls 4-3-7. Defrost end judgment conditions Defrost ends when either of the below defrost end judgment conditions is met. Condition 1: The temperatures are 42.8°F or higher at all temperatures sensors installed on the outdoor unit heat exchangers. However, if there is any other outdoor unit where the defrost end condition has not been met, defrost control continues for all outdoor units, and system defrost control is not ended.
3-WAY VRF SYSTEM Control Functions 5. Other Controls 5-1. Oil Control 5-1-1. Oil level 1 Oil level 2 Meaning Sufficient 1 Slightly low 0 Extremely low Oil state There is more than an adequate amount of oil in the compressor. Assessment This is the normal operating state of the system and not a problem. The compressor may contain an adequate amount of oil, but Check that oil control recovers oil. it may also contain less than an adequate amount of oil. There is not enough oil in the compressor.
3-WAY VRF SYSTEM Control Functions 6. Operation of Solenoid Valves 6-1. Refrigerant Control Valve [RCV] The main purpose of this valve is to detect the flow of refrigerant (refrigerant volume) on the indoor-unit side when the outdoor unit heat exchanger is functioning as a condenser. When the valve determines that there are signs of a low refrigerant level, refrigerant is supplied from the receiver tank to the system. (1) The OFF conditions take priority over the ON conditions for this valve.
3-WAY VRF SYSTEM Control Functions 6. Operation of Solenoid Valves 6-3. Balance Valve (BALV) 1 This valve moves some of the oil from the oil separator to the balance tube. (1) When unit is stopped This valve is always OFF. (2) When unit is operating (A) This valve is ON when separator oil self-recovery control is in progress. (B) This valve is ON when unit refrigerant oil recovery control is in progress (oil-supply unit).
7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, 3-WAY VRF SYSTEM MOV4] Control Functions 7-1. Types of Electronic Control Valves [U-72MF1U9, U-72MF1U9E, U-96MF1U9, U-96MF1U9E] Capacity Electronic control valve 72 96 Electronic control valve 1 Heat exchanger 1 valve Heat exchanger 1 valve Electronic control valve 2 Heat exchanger 2 valve Heat exchanger 2 valve Electronic control valve 4 For SC circuit For SC circuit 1 7-2.
7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, 3-WAY VRF SYSTEM MOV4] Control Functions 7-4. SC Circuit Electronic Control Valve [MOV4] 1 (1) Operation to increase SC During cooling operation, or mixed heating/cooling operation when the outdoor unit heat exchanger is functioning as a condenser, the liquid refrigerant which condenses at the outdoor unit heat exchanger flows into the receiver tank, and SC (sub-cool = supercooling) approaches 0°F.
3-WAY VRF SYSTEM Control Functions 8. Outdoor Fan Control 8-1. Fan mode These outdoor units utilize a DC fan motor that can be controlled in a maximum of 16 steps (16 modes). However, fan modes 15 and 16 can only be used if high static-pressure mode has been set. * For information concerning EEPROM settings, refer to the field application functions. 8-2. Outdoor Fan Min. Fan Mode and Max. Fan Mode Cooling operation Heating operation Min. fan mode Outdoor air temp. > 59°F: 1 Outdoor air temp.
3-WAY VRF SYSTEM Control Functions 9. Demand Control Serial-parallel I/O must be connected in order to perform demand control. The below input is received by serial-parallel I/O, and demand control is performed. The demand values can be set as needed with this device. For more information, refer to the field application functions.
3-WAY VRF SYSTEM Control Functions 10. Indoor Unit Control of the Electronic Control Valve 10-1. Normal Control (1) Cooling operation Position of electronic control valve 20 20 Outdoor unit stopped 20 20 20 20 Outdoor unit operating Stopped Fan Thermostat OFF Cooling Thermostat ON Performs SH control in the range of 55 – 480 pulses. 1 – * The SH target value is controlled so that the difference [E3 – E1] is 4 – 12°F, depending on the operating conditions.
10. Indoor Unit Control of the Electronic Control Valve 3-WAY VRF SYSTEM Control Functions 10-2.
3-WAY VRF SYSTEM Control Functions 11. Solenoid Valve Kit Control This device connects the solenoid valve kit which is used to switch between indoor unit cooling/heating for 3-WAY types. Heating Cooling Operation of the except type E1 solenoid valve kit Stopped Fan Thermostat OFF Thermostat ON Thermostat OFF Thermostat ON Discharge valve OFF OFF Intake valve OFF OFF Balance valve ON ON EP valve (evaporation temp.
3-WAY VRF SYSTEM Control Functions 12. Indoor Special Control 12-1. Switching Control (EC control) If the settings indicate that an RAP valve kit is present (for type E1, the setting on initial shipment from the factory is “present”), then the thermostat does not turn ON for 3 minutes after the indoor unit operating mode is changed from any mode other than heating (including stopped) to heating with thermostat ON. This is done in order to balance the pressure within the heat exchanger.
3-WAY VRF SYSTEM Control Functions 13. Discharge Temperature (1) Discharge temperature protection alarm This device sets an upper limit discharge temperature of 222°F for all compressors. When the discharge temperature reaches 222°F, that compressor is stopped and restarted. If the same high discharge condition occurs 4 times, then an alarm occurs.
3-WAY VRF SYSTEM Control Functions 14. Current Protection (1) Fan motor Alarm P22 Description Occurs when the fan motor detects overcurrent, or when the motor is locked and does not turn. (2) Inverter compressor 1 Alarm P16 P26 P29 H31 Description Occurs during ordinary operation when overcurrent (27 A) is detected. Occurs under the same conditions as P16 when the inverter compressor is operating at or above 80 Hz.
3-WAY VRF SYSTEM Control Functions 15. Low Oil Alarm Ordinary operation is resumed after system oil recovery control is completed. If a stop occurs again as a result of a low oil level, this alarm occurs. This alarm will not occur if system oil recovery control has not already been performed. However, the alarm may not occur if the outdoor unit where the system oil recovery conditions were met is not the same as the outdoor unit which stopped due to low oil level.
3-WAY VRF SYSTEM Control Functions 16. Pressure Sensor Failure 1 This system contains 2 types of pressure sensors: a high-pressure sensor and a low-pressure sensor.
3-WAY VRF SYSTEM Control Functions 17. Backup Operation 17-1. Automatic Backup Operation This system includes a function for automatic backup operation. An alarm is also displayed to inform the operator that a failure has occurred. (1) Alarms that result in automatic backup operation When compressor trouble or fan motor trouble makes emergency continued operation impossible, automatic backup operation mode is engaged.
3-WAY VRF SYSTEM Control Functions 17. Backup Operation 17-2. Manual Backup 1 If an alarm that does not result in automatic backup occurs frequently, possible causes include failure (such as refrigerant leakage) of a functional part at an outdoor unit other than the unit where the alarm occurs. In this case, because the outdoor unit service valve must be closed, backup operation must be performed manually.
3-WAY VRF SYSTEM Control Functions 18. Service Maintenance Functions The outdoor unit EEPROM settings can be used for the following functions. 18-1. Outdoor Unit Noise Countermeasure: EEPROM 05 (set at each outdoor unit) This unit includes 3 types of Quiet modes. (However, when they are engaged, operation is in Quiet mode 24 hours a day.) Selecting a Quiet mode results in operation that gives priority to reducing noise.
3-WAY VRF SYSTEM Control Functions 18. Service Maintenance Functions 18-5. Automatic Backup Mode: Outdoor EEPROM 49 (set only on outdoor unit No. 1) Two types of automatic backup modes (when multiple outdoor units are installed) can be selected. Setting 1 Operation Condition 0 Backup outdoor units operate only during special control. 1 Only the backup compressors remain stopped. Other OK compressors installed in the same outdoor unit operate as normal.
3-WAY VRF SYSTEM Control Functions 18. Service Maintenance Functions 18-9. Compressor operating sequence: Outdoor EEPROM 46 (set at outdoor units which include CCU functions) When this setting is set to “1,” the compressors start in sequence beginning from the No. 1 outdoor unit. (The setting is “0” at the time of shipment. With this setting, compressors with lower operating time are started first in order to balance the compressor operating times.) 18-10.
3-WAY VRF SYSTEM Control Functions 19. Other Functions 19-1. Snowfall Sensor Functions: Outdoor EEPROM 04 A unit identified as having a snowfall sensor attached will periodically send a signal indicating the snowfall sensor input status to all outdoor units in the same system (or all wired outdoor units in the case of linked systems). It is therefore unnecessary to install and wire multiple snowfall sensors. (1) Snowfall sensor settings Setting 1 Operation 0 Sensor input not present.
3-WAY VRF SYSTEM Control Functions 19. Other Functions (3) Outdoor unit PCB LED indications in judgment mode Judgment mode Normal Insufficient gas Overcharge Judgment not possible LED1 LED2 Blinking Blinking ON ON Blinking OFF OFF Blinking Recommended response Charge with refrigerant a little at a time. Recover refrigerant a little at a time. Blinking alternately When judgment mode is not engaged, the LED indicates the normal display (OFF), or else indicates alarms or other information.
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3-WAY VRF SYSTEM Outdoor Unit Repair Procedures Contents 2. OUTDOOR UNIT REPAIR PROCEDURES 1. Removing Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2. Removing Electrical Component Box and Duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 3. Discharging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 4. Backup Operation . . . . . . . . . . . . . . . . . .
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 1. Removing Panels Procedures: 1. Removing Panels 2. Removing Electrical Component Box and Duct 3. Discharging Compressor Oil 4. Backup Operation 5. Recovering Refrigerant 6. Checking for Leakage After Repair 7. Evacuating System 8. Charging Compressor Oil 9. Pumping Out Refrigerant from Outdoor Unit (when repairing parts other than compressor) 10. Compressor 2 11. High and Low Pressure Sensors 12. Replacing 4-way valve (1) Front panel removal (Fig.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 2. Removing Electrical Component Box and Duct Be sure to turn off the power before removing the electrical component box. Then check that the power LED (D53) on the control PCB of the outdoor unit is not lit. (1) Remove the electrical component box cover (remove 6 screws). (Fig. 2-3) Electrical component box cove r 2 Fig. 2-3 (2) Remove power and control wires from terminals. (3) Remove internal wires with extended connectors on the outdoor control PCB.
2. Removing Electrical Component Box and Duct 3-WAY VRF SYSTEM Outdoor Unit Repair Procedures (7) Remove the lower duct. (2 screws, 1 tab) (Fig. 2-6) Lower duct 2 Fig. 2-6 (8) Remove the upper duct. (3 screws) (Fig. 2-7) Upper duct Fig.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 3. Discharging Compressor Oil Discharged oil can be used for checking the condition of the system. Based on the appearance and color of the discharged oil, a judgment can be made on whether the system is operating normally or not. 3-1. Discharging Oil from Oil Separator Recover the refrigerant from the outdoor unit following the procedure given in “5. Recovering Refrigerant.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 4. Backup Operation This system includes an emergency automatic backup function that allows the A/C to operate during the period after trouble occurs until repairs are made. However, during repair and at other times, use manual backup operation. 4-1. Automatic Backup For details, refer to the control functions section.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 4. Backup Operation If the No. 1 unit (main unit) has failed, a different outdoor unit must be set as the No. 1 unit (main unit). • Settings at the failed No. 1 outdoor unit – No particular changes – However, close all service valves (suction tube, discharge tube, liquid tube, balance tube) at the failed outdoor unit, and disconnect the wiring between the outdoor units (main-sub unit wiring).
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 4. Backup Operation • After adjusting the amount of refrigerant, turn OFF the power at the failed outdoor unit, release the short-circuit at the vacuum application pin, and close the liquid tube valve at the failed outdoor unit. * Refrigerant recovery is not affected by the power status of the failed outdoor unit. However, collecting refrigerant in the failed outdoor unit is affected by whether the power at that outdoor unit can be turned ON.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 5. 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, flathead screwdriver, and outdoor unit maintenance remote controller. 5-1.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 5. Recovering Refrigerant 5-2. 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 5-2-1. Cooling operation (for all units) Ball valve is provided in the indoor unit YES NO 5-2-3. Refrigerant recovery procedures (2) 5-2-2.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 5. Recovering Refrigerant 5-2-1. Cooling operation (for all units) (1) If the remote controller (CZ-RTC2) is used for maintenance of the outdoor unit ➀ Connect the outdoor unit maintenance remote controller to the RC connector (CN006) (3P) (BLU) on any (CHECK) one of the outdoor unit control PCBs. Then start a test run of all units. (Press and hold the button for 4 seconds.) (MODE) button and change to cooling operation.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 5. Recovering Refrigerant (6) Recover the remaining refrigerant from the indoor unit using the refrigerant recovery unit. Ball valve (separately purchased) NOTE Service port Suction tube To determine completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 5. Recovering Refrigerant ➈ Using hoses with Schrader-type push-to-release valves, connect the manifold gauge valves to the suction line service port, the discharge line service port and the liquid line service port in the next outdoor unit to undergo pump down. (Fig. 2-11) Remaining refrigerant in the system may cause internal pressure. Check that each CAUTION valve on the manifold gauge is tightly closed.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 6. Checking for Leakage After Repair 6-1. Pressure Check for Leakage of Outdoor Unit 2 After completing repair of the outdoor unit, carry out the following leakage check. (1) Check that all service valves for suction tube, discharge tube, liquid tube, and balance tube in the repaired outdoor unit are fully closed. (2) Connect the manifold gauge valves to the high- and low-pressure outlet ports of the outdoor unit.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 7. 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. 7-1. Evacuating Repaired Outdoor Unit (1) Check that each service valve of the suction tube, discharge tube, liquid tube, and balance tube in the outdoor unit are fully closed. (2) Connect the manifold gauge valves to the high-pressure and low-pressure sensor outlets of the outdoor unit.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 8. Charging Compressor Oil 8-1. If Refrigerant Has Already Been Charged to Outdoor Unit Be sure to use an exclusive oil-charging tank for charging compressor oil. Prior to charging, carry out vacuum drying inside the tank and take care that no air (in the form of bubbles) is permitted to enter the tank. The oil charging procedures are given below. * The receiver tank used for maintenance may be used as an exclusive oil-charging tank.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 8. Charging Compressor Oil (2) Charging compressor oil into oil-charging tank Connect a piece of pipe to the lower valve and then insert the other end deeply into the bottom of the oil container. Make sure you avoid letting any air be sucked into the tube. Next, run the vacuum pump and open the manifold gauge valves, then open the upper and lower valves to begin charging oil into the charging tank. First close the lower and then, this one before stopping.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 8. Charging Compressor Oil Next follow the instructions in “5-2-1. Cooling operation (for all units)” at the outdoor unit where oil will be charged, and start cooling operation at all units. When the operating conditions have stabilized, perform steps 1, 2, and 3 in sequence and open the valves.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 8. Charging Compressor Oil High-pressure outlet port (For 5/16" (7.94mm)-dia. connector) Oil tube service port (For 1/4" (6.35mm)-dia. connector) Low-pressure outlet port (For 5/16" (7.94mm) -dia. connector) Oil Manifold gauge Lo Hi Vacuum pump 2 Fig. 2-19 8-3.
9. Pumping Out Refrigerant from Outdoor Unit 3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 9-1. If Remote Controller (CZ-RTC2) is Used for Maintenance of Outdoor Unit (1) Refer to “4. Backup Operation” and perform backup operation. (2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be repaired.
9. Pumping Out Refrigerant from Outdoor Unit 3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 9-2. If Remote Controller (CZ-RTC2) is Not Available for Maintenance of the Outdoor Unit (1) Refer to “4. Backup Operation” and perform backup operation. (2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be repaired.
9. Pumping Out Refrigerant from Outdoor Unit Faulty outdoor unit Manifold gauge Lo Hi High-pressure outlet port (For 5/16" (7.94mm-dia. connector) 3-WAY VRF SYSTEM Outdoor Unit Repair Procedures Other outdoor unit Low-pressure outlet port (For 5/16" (7.94mm-dia. connector) Liquid tube service port (For 5/16" (7.94mm-dia. connector) Refrigerant recovery cylinder 2 Measuring scale Connect from here to refrigerant recovery unit Fig.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-1. Compressor Trouble Diagnosis and Check Methods Generally, compressor failures can be classified into the following categories. (1) Mechanical trouble → (A) Locking (intrusion of foreign objects, galling, etc.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-2. Replacing the Compressor(s) 10-2-1. Replacing only the failed compressor (1) (2) (3) (4) (5) 2 (6) (7) (8) If backup operation is required, follow the instructions in “4. Backup Operation” and engage backup operation. Follow the instructions in “10-3. Removing and Installing Compressors” and replace the failed compressor. Fully close the high- and low-pressure gauge valves on the manifold gauge, then stop the vacuum pump.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-2-2. Replacing all compressors in a failed unit (1) (2) (3) (4) (5) Follow the instructions in “3. Discharging Compressor Oil” and drain the oil from the oil separator in the failed unit. Measure the amount of drained oil. If backup operation is required, follow the instructions in “4. Backup Operation” and engage backup operation. Follow the instructions in “10-3.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-2-3. Replacing all compressors in a system (1) (2) (3) (4) (5) (6) Follow the instructions in “3. Discharging Compressor Oil” and drain the oil from the oil separators in all outdoor units. Measure the amount of drained oil. Follow the instructions in “10-3. Removing and Installing Compressors” and replace all compressors in the system. Follow the instructions in “6.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-2-4. Dry core cleaning If burning or other failures occur repeatedly at compressors within the same system, in many cases the cause is acid, sludge, carbon, or other substances that remain in the refrigeration cycle as the result of insufficient cleaning. If, when the oil is inspected, there is an outdoor unit where the oil color phase is 4.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor (15) At all outdoor units where dry cores were removed, pressurize with 522.1 psi of nitrogen from the liquid tube service port and check for leaks. (16) After evacuating all nitrogen gas from the tubing, apply vacuum to all outdoor units where dry cores were removed until the pressure is –14.7 psig (5 Torr) or less. (17) INSTALLATION: Refer to the “Information for the Person in Charge of Installation” items.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor 10-3. Removing and Installing Compressors When removing and installing compressors, use sufficient caution to ensure that moisture or other substances do not enter the refrigerant tubing system. 10-3-1. Replacing compressors * For all types 72 and 96, follow the replacement procedure below.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor ■ Installation (1) (2) (3) (4) Remove the rubber stopper and tube cap (brazed) from the new compressor. Install the crankcase heater onto the new compressor. Place the 2 pieces of cushioning rubber in the designated positions on the compressor. Place the 2 pieces of cushioning rubber onto the legs of the new compressor.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor (B) Replacing the constant-speed compressor (Compressor 2 on remote controller alarm display) ■ Removal (1) (2) (3) (4) (5) (6) Connect the manifold gauge to the high- and low-pressure outlet ports at the outdoor unit where the compressor will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas replacement. Follow the instructions in “1. Removing Panels” and “2.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor ■ Installation (1) (2) Remove the 2 brazed tube caps (2 pieces) from the compressor. Remove hexagonal caps from the compressor. * When removing the hexagonal caps, hold the fixing nut at the main unit side so as not to loose it with a wrench or spanner. And then, loosen and remove the hexagonal cap. Hexagonal cap Oil equalizer tube connector parts 2 Fixing nut at the main unit side O-ring Fig.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor Brazing locations (3) Bolt Washer: 1 Rubber washer: 1 (1 each at the 3 locations) Protect the oil equalizer tube connectors Cushioning rubber guide Front view Fig. 2-28 (6) Set the remaining cushioning rubber beneath the new compressor leg at the locations shown in the figure 2-28.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 10. Compressor (C) Replacing multiple compressors ■ Removal (1) Follow the instructions in “(A) Replacing the inverter compressor,” “(B) Replacing the constant-speed compressor,” and remove the compressors. * There is no predetermined sequence for removal; any compressor may be removed first. ■ Installation (1) Follow the instructions in “(A) Replacing the inverter compressor,” “(B) Replacing the constant-speed compressor,” and remove the compressors.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 11. High and Low Pressure Sensors The outdoor unit connection ports for the high and low pressure sensors employ Schrader-type push-to-release valves. Therefore it is not necessary to recover refrigerant when removing and installing them. 11-1. Removing the High Pressure Sensor (1) (2) (3) Follow the instructions in “1. Removing Panels” and “2.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 12. Replacing 4-way valve When replacing 4-way valve of type 72 (for type with the inverter compressor), be sure to protect check valves, which are located adjacent to the 4-way valve, while performing replacement work. Type 96 (for type with 1 or 2 compressor) is not located near to the check valves, therefore no protection is necessary. 12-1.
3-WAY VRF SYSTEM Outdoor Unit Repair Procedures 12. Replacing 4-way valve 12-2. When the replacement is not available from the right side of the unit (1) (2) (3) Follow the instructions of “10. Compressor” and remove the constant-speed compressor. Connect the manifold gauge to the high and low-pressure outlet ports at the outdoor unit where the 4-way valve will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas replacement.
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3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller Contents 3. OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER 1. Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 2. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 3. Ordinary Display Controls and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 4.
3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller 1. Overview [Service Checker Section] OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER (CZ-RTC2) for 3-WAY VRF ■ 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. The outdoor unit maintenance remote controller is used to set and change these EEPROM data.
3-WAY 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 • Test run of all indoor units • Double-speed operation of indoor units (Do not use for actual operation. Doing so may damage the devices.) (2) Display: The following can be displayed. • Alarm details display • No.
3-WAY 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) Special service checker wiring Relay connector (2P, WHT) Remote controller Ass’y 3 ● ● ● If the communications line in the inter-unit control wiring is connected, it can be left as-is.
3. Ordinary Display Controls and Functions 3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller ● All units start/stop (Fig. 3-1) The (ON/OFF operation) button can be used to start and stop all the indoor units. • The LED turns ON when 1 or more indoor units is operating. • The LED blinks when an alarm has occurred at 1 or more indoor units during operation. LED ● Switching between cooling/heating (Fig. 3-1) The (MODE) button switches between heating and cooling modes.
3. Ordinary Display Controls and Functions 3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller ■ Display (functions) • Use the temperature setting Item code ➀ 3 and buttons to change the item code. Item Remarks Outdoor unit alarm ➁ Alarm code display No. of connected indoor units Quantity Unit Nos. of connected indoor unit 7-segment display Operating status of indoor unit 7-segment display Thermostat ON status of indoor unit 7-segment display No.
3. Ordinary Display Controls and Functions (3) XX-YY R.C. 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 (1 – 8). “1” appears when there is only 1 outdoor unit. 3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller Locations where ➀, ➁, and ➂ are displayed as shown in Fig. 3-3. 2 3 01: 4 units connected 02:
3. Ordinary Display Controls and Functions 3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller ■ Concerning the 7-segment, 4-digit display remote controller timer display ) display and The connected unit Nos. are displayed as shown below, using the 7-segment 4-digit ( the colon. ● Display for unit Nos. 1 − 20 OFF OFF 1 3 8 10 15 20 ON OFF ON OFF 26 23 1 ~ 20 21 ~ 40 41 ~ 60 61 ~ 80 is not displayed.
3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller 4. Monitoring Operations Display the indoor unit and outdoor unit sensor temperatures. ➀ Press and hold the (CHECK) button and buttons simultaneously for 4 seconds or longer to switch to temperature monitor mode. During temperature monitoring, is lit. (The display and operations are the same as when monitor mode is started from the unit remote controller.
3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller 4. Monitoring Operations ■ Display of unit No. 1 (main unit) DN Description Remarks Intake temp. °F E1 °F E2 °F E3 °F Discharge temp. °F Discharge temp. setting °F Indoor unit electronic control valve position STEP Discharge temp. 1 °F Discharge temp. 2 °F High-pressure sensor temp. °F Heat exchanger gas 1 °F Heat exchanger liquid 1 °F Heat exchanger gas 2 °F Heat exchanger liquid 2 °F Outdoor air temp.
5. Outdoor Unit Alarm History Monitor 3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller • Displays outdoor unit alarms only. Does not display indoor unit alarms. • Check the indoor unit alarm histories separately using the indoor unit remote controllers or other control device. ➀ Press and hold the (CHECK) button and button simultaneously for 4 seconds or longer to change to outdoor unit alarm history mode. During temperature monitoring, displays.
3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller 6. Mode Settings ■ Setting mode 1 A Display of first 4 digits ➀ Press and hold the (CHECK) button and (VENTILATION) button simultaneously for 4 seconds or longer. ➁ Use the temperature setting and buttons to change the item code. The item codes and setting data are shown in the table below. ➂ Use the timer time and buttons to change the setting data. 5 To confirm the changed setting data, press the button.
3-WAY VRF SYSTEM Outdoor Unit Maintenance Remote Controller 6. Mode Settings ■ Setting mode 2 ➀ Press and hold the (CHECK) button, simultaneously for 4 seconds or longer. button, and button ➁ Use the temperature setting and buttons to change the item code. The item codes and setting data are shown in the table below. ➂ Use the timer time and buttons to change the setting data. To confirm the changed setting data, press the button.
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3-WAY VRF SYSTEM Remote Controller Functions Contents 4. REMOTE CONTROLLER FUNCTIONS 1. Simple Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 2. Detailed Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 3. Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-WAY 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 groupcontrol indoor unit to which the remote controller used for simple settings is connected.
3-WAY VRF SYSTEM Remote Controller Functions 1. Simple Settings Function List of Simple Setting Items Item code Item Filter sign ON time (fitlter life time) Degree of filter fouling No. 0000 0001 0002 0003 0004 0005 0000 0001 0001 0002 0003 Setting data Description Not displayed 150 hours 2,500 hours 5,000 hours 10,000 hours Use the filter clogging sensor. Standard (setting at time of shipping) Highly fouled (Filter sign ON time is reduced to one-half the set time.
3-WAY 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. When detailed settings mode is engaged, operation stops at the individual or group-control indoor unit where the remote controller used for detailed settings is connected. Simple settings items can also be set at this time.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function List of Detailed Setting Items Item code Item Type Indoor unit capacity Setting data No. Description No. Description 0000 1-Way Cassette (D1) 0001 0006 High Static Pressure Ducted (E1) 0007 Ceiling (T1) 0010 Floor Standing (P1) 0011 Concealed Floor Standing (R1) No.
3-WAY VRF SYSTEM Remote Controller Functions 2.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item Automatic drain pump operation Ventilation fan operation Wired remote controller sensor “Operation change control in progress” display OFF reminder function for when weekly timer is used Discharge temperature control Setting data Description No. 0000 0001 No forced operation Forced operation for 1 minute 0060 0000 0001 0000 0001 Continuous operation None Ventilation fan operated by remote controller. Not used.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item No. 0000 0001 Fan tap setting (Fan tap change in order to prevent drop in air discharge caused by filter installation) 0003 DC fan tap operating mode Standard High ceiling use For low static-pressure filter High ceiling use For low static-pressure filter 0000 0001 0002 For air-blocking material For air-blocking material No humidifier output 1 sec. 2 sec. 0058 0059 0060 0000 58 sec. 59 sec.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Simple setting items Item code Item Description 01 Filter sign ON time setting (filter lifetime) Changes the indoor unit filter lifetime when a high-performance filter or other optional product is installed. 02 Degree of filter fouling Reduces the filter sign ON time to 1/2 of the standard time (setting at the time of shipping) for cases when filter fouling is more severe than normal.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item 03 Central control address 04 Operating mode priority change Description Set when using a central control device. Used when setting the central control address manually from the remote controller. Note (1) NOTE (1) Explanation of operation mode priority change Enabled only in 2WAY VRF heat-pump models.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function When the operating mode at the priority remote controller is changed, the operating modes of other remote controllers change as shown below.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item Description 10 Unit type 11 Indoor unit capacity 12 System (outdoor unit) address 13 Indoor unit address 14 Group address 17 Cooling intake temperature shift Shifts the intake temperature during cooling and dry operation. (Enabled only when the body thermostat is used.) Increase this value when it is difficult to turn the thermostat ON.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function Item code Item 1F (Upper limit) 20 (Lower limit) 21 (Upper limit) 22 (Lower limit) 23 (Upper limit) 24 (Lower limit) Description Cooling Change to the remote control temperature setting range 25 (Upper limit) 26 (Lower limit) Heating Drying This setting changes the temperature range (upper limit and lower limit) which is set from the remote controller or central control device.
3-WAY VRF SYSTEM Remote Controller Functions 2. Detailed Settings Function (Continued from previous page) Item code Item Description 3C Heat exchanger temperature for cold air discharge The heat exchanger temperature control point for prevention of cold air discharge during heating operation can be changed. 3d Fan output switching The indoor unit PCB optional output for the fan can be switched according to the purpose of use.
3-WAY 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 Test run Description Operation with forced thermostat ON Sensor temperature display Temperature display from each sensor Servicing check display Alarm history display Button operation Press and hold the Reset operation button for 4 seconds or longer.
3-WAY VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions Test Run Function Operates the unit with the thermostat forced ON. ➀ Press and hold the longer. ➁ “Test” appears on the remote controller LCD display (Fig. 4-3). ➂ Start operation. ➃ Press the button to return to normal remote controller display. 2 button for 4 seconds or 3 CZ-RTC2 1 4 Fig.
3-WAY VRF SYSTEM Remote Controller Functions 3. Remote Controller Servicing Functions ■ Sensor Temperature Display Function (displayed regardless of whether unit is operating or stopped) 2 The procedure below displays the sensor temperatures from the remote controller, indoor unit, and outdoor unit on the remote controller. ➀ Press and hold the and buttons simultaneously for 4 seconds or longer. ➁ The unit No. “X-X” (main unit No.
3. Remote Controller Servicing Functions Indoor unit sensors 02 Intake temp. 03 E1 04 E2 05 E3 06 Discharge temp. 07 Discharge temp. setting 08 Position of indoor unit electronic control valve Unit No.1 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 3-WAY VRF SYSTEM Remote Controller Functions Outdoor unit sensors Unit No.2 2A Discharge temp. 1 2B Discharge temp. 2 2C High-pressure sensor temp.
3-WAY VRF SYSTEM Trouble Diagnosis Contents 5. TROUBLE DIAGNOSIS 1. Contents of Remote Controller Switch Alarm Display . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 2. Outdoor Unit Control Panel LED Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 3. Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 4. 3-WAY VRF Alarm Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wired remote control display Serial communication errors Mis-setting Remote controller is detecting Error in receiving serial communication signal. (Signal from error signal from indoor unit. main indoor unit in case of group control) Outdoor system address, indoor unit address, or indoor unit address independent/main/sub unit setting has not been made. (Auto address is not completed.) Error in transmitting serial communication signal.
3-WAY VRF SYSTEM Trouble Diagnosis Blinking: Wired remote control display Thermistor fault Outdoor unit Compressor 1 (INV) discharge temp. sensor Compressor 2 (constant speed) discharge temp. sensor Outdoor air temp. sensor Heat exchanger 1 liquid temp. sensor Heat exchanger 1 gas temp. sensor Compressor intake temp. sensor (suction temp) High-pressure sensor Low-pressure sensor Heat exchanger 2 liquid temp. sensor Heat exchanger 2 gas temp.
3-WAY VRF SYSTEM Trouble Diagnosis 2. Outdoor Unit Control Panel LED Display ( : ON : Blinking : OFF) LED (RED) Display meaning 1 2 After the power is turned ON (and automatic address setting is not in progress), no communication with the indoor units in that system is possible.
3-WAY VRF SYSTEM Trouble Diagnosis 3. Remote Controller Servicing Functions Sensor temperature display function (displayed both when unit is running and stopped) 2 • 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. ➀ Press and hold the (CHECK) button and button simultaneously for 4 seconds or longer.
3-WAY VRF SYSTEM Trouble Diagnosis 3. Remote Controller Servicing Functions Sensor Temperature Relationship Table Location where sensor is installed Sensor address Sensor address Sensor type Remote controller temperature Sensor type Discharge temperature sensor Indoor unit intake temperature Indoor unit heat exchanger temperature (E1) Indoor unit Indoor unit electronic expansion valve position Indoor unit heat exchanger temperature (E3) Unit Unit No. 1 No. 2 Unit Unit No. 1 No.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes With type 72, the INV compressor is compressor 1. With type 96, the INV compressor is compressor 1, and the constant-speed compressor is compressors 2. Alarm code E06 E12 E15 E16 E20 E24 Alarm meaning Page 5-9 5-9 5-9 5-10 5-10 5-10 E25 E26 E29 Outdoor unit failed to receive serial communication signals from indoor unit. Automatic address setting start is prohibited.
3-WAY VRF SYSTEM Trouble Diagnosis 4.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes E06 Alarm Alarm code E06 Alarm meaning Alarm conditions Probable cause Outdoor unit failed to receive serial communication signals from indoor unit. Outdoor unit failed to receive serial communication signals from indoor unit. (1) The indoor unit power was cut OFF after initial communications were completed. (2) An open circuit or short circuit occurred in the inter-unit control wiring after initial communications were completed.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes E16 Alarm Alarm code E16 Alarm meaning Alarm conditions Automatic address setting alarm (too many units) • The number of indoor units was too many when automatic address setting was performed. • After initial communications were completed, an unrecognized unit was detected. (1) The number of indoor units set at the indoor unit quantity setting SW (S004, S005) on the outdoor unit PCB is less than the number set.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes E25 Alarm Alarm code E25 Alarm meaning Alarm conditions Outdoor unit address setting failure (duplication) Communication by outdoor unit main-sub control wiring was received that contained the same address as that unit 5 times or more within 3 minutes. The unit number is set incorrectly. Check the unit number again. Correct the incorrect unit number setting.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes F04, F05 Alarm Alarm code F04, F05 Alarm meaning Compressor 1 discharge temperature sensor trouble, compressor 2 discharge temperature sensor trouble (1) Discharge temp. of 212°F or higher was detected 20 minutes or more after that compressor stopped operating. (2) Discharge temp. of 176°F or higher was detected after all compressors had been stopped for 60 minutes or longer. (3) A/D step is 10 steps or less (short circuit).
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes Check Correction Example Notes (3) Leakage from the discharge tube check valve Trouble: Although the other compressor is operating and this compressor is stopped, the discharge temperature of this compressor rises together with the temperature of the other compressor. (4) The ambient temperature around the outdoor unit when it is stopped is 109 °F or higher.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes F08 Alarm Alarm code F08 Alarm meaning Alarm conditions Outdoor air temperature sensor trouble (1) A/D step is 10 steps or less (short circuit). (2) A/D step is 1014 steps or more (open circuit) (1) Sensor malfunction (including connector) (2) PCB malfunction (1) Measure the sensor resistance. Check that the sensor is operating normally.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes F16 Alarm Alarm code F16 Alarm meaning High-pressure sensor trouble (abnormal rise in high pressure) (In some cases this may not be the result of a high-pressure sensor malfunction.) • High-pressure SW activated although the detected pressure was lower (439.4 psi or below) than the high-pressure SW activation pressure: Undershift • High-pressure SW failed to activate although the detected pressure was higher (497.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes Correction Example (1) Replace the high-pressure sensor. Caution: Because the high-pressure sensor connection employs a Schrader-type valve, it can be removed and replaced. However, the high-pressure sensor can be easily damaged by high voltage; therefore use sufficient caution with regard to static electricity. (2) Replace the PCB. (3) Correct the locations of problems in the refrigeration cycle.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes H11, H12 Alarm Alarm code H11, H12 Alarm meaning H11: Constant speed compressor 2 overcurrent alarm H12: Constant speed compressor 2 lock current alarm H11: During operation, the compressor current value exceeded 20 A for 30 seconds or longer. However this alarm is not detected for 4 seconds after the compressor starts. H12: During operation, the compressor current value exceeded 29 A for 4 seconds or longer.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes H03, H13 Alarm Alarm code H03, H13 Alarm meaning H03: Compressor 1 CT sensor disconnected or short-circuit H13: Compressor 2 CT sensor disconnected or short-circuit Compressor 1: Current value of more than 18.0 A is detected while the compressor 1 is stopped. Compressor 2: Current value at compressor 2 is less than 2.0 A when 2 seconds or more had passed after the compressors began operation and output.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes H06 Alarm Alarm code H06 Alarm meaning Alarm conditions Abnormal low-pressure drop A pre-trip occurs during the unit's operation when the low-pressure sensor installed at constant low-pressure parts detects a pressure of 7.25 psi or less continuously for 2 minutes, or an instantaneous pressure of 2.90 psi or less. (These values represent abnormal low pressure which may damage the compressor.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes H07 Alarm Alarm code H07 Alarm meaning Alarm conditions No-oil alarm This alarm occurs when oil does not flow for a specified amount of time in tubing where oil flow constantly. (The presence of oil is detected by a temperature sensor.) Judgment method: Tcal (calculated by the formula below from the oil temperature) is compared with the discharge temperature. If Tcal is higher than the discharge temperature then oil is judged to be present.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes H08, H27 Alarm Alarm code H08, H27 Alarm meaning H08: Trouble (open circuit) with the oil sensor (connection) at compressor 1 H27: Trouble (open circuit) with the oil sensor (connection) at compressor 2 This alarm occurs when a connector connection (pins 1 and 2 for compressor 1, pins 4 and 5 for compressor 2 is open. Disconnected connector. Check that the connector is securely connected. (1) Connect the connector.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes L04 Alarm Alarm code L04 Alarm meaning Alarm conditions Outdoor system address duplication Communication by inter-unit control wiring was received that contained the same address as that unit 5 times or more within 3 minutes. Incorrect outdoor system address settings Check the system address settings again. Correct the system address settings.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes P03, P17 Alarm Alarm code Alarm meaning Alarm conditions Probable cause Check P03, P17 Compressor 1 discharge temperature trouble; Compressor 2 discharge temperature trouble Inverter compressor 1: Temperature is 222°F or higher and pre-trip stop has occurred. Compressors 2 (constant speed): Pre-trip stop occurs at 222°F or above. The alarm occurs when pre-trip stop occurs more than once.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes Correction Example Notes (1) Replace the sensor. (2) Replace the outdoor unit PCB. (3) Correct the problem locations. All of the probable causes Operates continuously for a set length of time. Indicates 2.5 minutes or longer for an inverter unit and 30 seconds or longer for a constantspeed compressor. P04 Alarm Alarm code Alarm meaning Alarm conditions Probable cause Check 5 Correction Example Notes P04 High-pressure switch activated.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes P16 Alarm Alarm code Alarm meaning Alarm conditions Probable cause Check Correction Example Notes P16 Compressor 1 (INV) overcurrent alarm This alarm occurs when current trouble or current detection trouble occur at an inverter frequency of less than 80 Hz after start (when trouble judgment current is detected in the primary or secondary current, or when an instantaneous secondary current of 48 A or higher is detected.
3-WAY VRF SYSTEM Trouble Diagnosis 4. 3-WAY VRF Alarm Codes P26 Alarm Alarm code P26 Alarm meaning Alarm conditions Inverter compressor high-frequency overcurrent alarm This alarm occurs when current trouble or current detection trouble occurs at an inverter frequency of 80 Hz or higher after start (when trouble judgment current is detected in the primary or secondary current, or when an instantaneous secondary current of 48 A or higher is detected). The detection methods are the same as for P16.
5. Blinking Inspection Display on the Remote Controller 3-WAY VRF SYSTEM Trouble Diagnosis Blinking inspection display (2) (compressor magnet SW seizing detection) Alarm code (Blinking inspection display) Alarm meaning Compressor magnet SW seizing detected Status: Although an outdoor unit exists where the outdoor unit fan is running, no compressors in the system are operating. Because the fan is running only at the outdoor unit where seizing was detected, check the corresponding outdoor unit.
3-WAY VRF SYSTEM Trouble Diagnosis 6. Inspection of Parts (1) High-pressure switch (63PH1, 63PH2) • 63PH1: Disconnect the CN042 connector (3P, WHT) from the outdoor unit control panel. Measure the resistance between socket pins 1 and 3. The resistance is OK if the result is 0 Ω. • 63PH2: Disconnect the CN044 connector (3P, RED) from the outdoor unit control panel. Measure the resistance between socket pins 1 and 3. The resistance is OK if the result is 0 Ω.
3-WAY VRF SYSTEM Trouble Diagnosis 7. Test Pin When the test pin on the outdoor unit control PCB is short-circuited, each part can be operated individually. • After turning OFF the main unit power, short circuit the test pin (CN022, WHT), then turn the power back ON. Output is performed in the sequence shown in the table below, for 0.5 seconds each.
3-WAY VRF SYSTEM Trouble Diagnosis 8. Thermister Characteristics Curve 8-1. Room temp.sensor Temperature sensor 10 9 8 Resistance 7 6 5 4 3 2 1 10 15 20 25 30 35 40 45 50 55 Temperature (˚C) 8-2. Indoor heat exch.
3-WAY VRF SYSTEM Trouble Diagnosis 8. Thermister Characteristics Curve 8-3. Outdoor temp. sensor, Compressor suction gas temp. sensor Outdoor heat exch. coil sensor, Oil temp. sensor Outdoor temperature, Suction gas temperature sensor Heat exchanger temperature, Oil temperature sensor 35 8 30 7 6 25 5 20 Resistance Resistance 40 15 10 3 2 1 5 0 4 0 -20 -15 -10 -5 0 5 10 15 20 20 30 40 50 60 Temperature (°C) Temperature (°C) 8-4. Compressor discharge gas temp.
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