AIRWELL VVFA-335R-01T32 (01) PDF MANUAL

Key features include:

Energy Efficiency Upgrades:

• Full DC fan motor with zigzag design for reduced airflow disturbance, less vibration, and pressure loss.

• Super big diameter fan (550mm) to enhance heat exchange efficiency.

• Changed exchanger pipe diameter (from Φ8 to Φ7) with high-efficiency corrugated fins, increasing heat exchanger area and improving efficiency by 30%.

• Special structure for increased wind-cooled PCB effect.

• PID control for precise management of EEV opening degree, compressor rotation speed, and fan speed.

• Tube-in-tube type two-stage sub-cooling design to enhance efficiency (on double fan models).

• Larger capacity full DC inverter compressor.

• Double rotor compressor with keel motor technology, increasing efficiency by 10% compared to normal types.

Control Technology:

• Double pressure sensor with PID control: Adjusts target evaporation/condensation temperature to increase compressor frequency quickly.

• Intelligent defrosting technology: Judges frosting degree based on low pressure and defrost temperature sensor changes, entering defrost only when necessary to extend heating time.

Cleaning Technology:

• Inverse balancing technology: Indoor & outdoor unit self-cleaning module uses waste heat for heating, defrosting, and sterilizing the indoor unit without stopping.

• Quick setting and cleaning technology: Uses accurate temperature control for rapid frost and instant frost effects.

Installation Flexibility:

• Easy Installation: 4-way pipe connection (front, back, left, right).

• Long Piping: Total pipe length up to 300m.

• High Drop: Maximum drop between indoor and outdoor units up to 50m (or 40m depending on model/configuration, refer to specs).

• Versatile Environment: Suitable for various installation environments (double fan models).

Nominal conditions are:

• Indoor temperature (cooling): 27 DB(°C)/19 WB(°C)

• Indoor temperature (heating): 20 DB(°C)/14.5 WB(°C)

• Outdoor temperature (cooling): 35 DB(°C)/24 WB(°C)

• Outdoor temperature (heating): 7 DB(°C)/6 WB(°C)

• Data is measured with 7.5m equivalent pipe and 0m height difference.

• Noise level is measured in the third octave band limited values in the semi-anechoic chamber, using a real time analyser calibrated sound intensity meter (sound pressure noise level).

The switch BM1-1 is used for locking the indoor units number.

The initial status is “OFF”. After power on, the display board will show “***” which indicates the number of Indoor units that the outdoor unit can communicate with.

If it matches the actual number of indoor units, change the setting from “OFF” to “ON”. If it does not match, solve the communication problem first before changing the switch.

The other BM1 switches (BM1-2 to BM1-8) relate to model settings and require setup on site according to the table provided in the manual.

Dial Switch Introduction

The cooling capacity to be known is calculated using the following formula:

Cooling capacity = Nominal cooling capacity * A * B * C * D * E

Where:

A = Capacity compensation value based on indoor air wet-bulb temperature condition.

B = Capacity compensation value based on outdoor air dry-bulb temperature condition.

C = Capacity modification value under airflow variation rate of indoor unit group (only for duct units).

D = Capacity compensation suitable for total capability of indoor unit group (%).

E = Capacity compensation value based on pipe length, pipe diameter, and height drop.

Refer to the performance curves in the manual for the specific values of A, B, C, D, and E based on your operating conditions and installation specifics.

Note: The main pipe diameter should be enlarged one size if the single way pipe length is over 90m. Compensation factors should be adjusted for vertical height drops based on the provided table if outdoor is lower than indoor in cooling mode.

Adjustment Factor for Vertical Height Drop (Cooling Mode – Outdoor Lower than Indoor)

The heating capacity to be known is calculated using the following formula:

Heating capacity = Nominal heating capacity * A * B * C * D * E * F

Where:

A = Capacity compensation value based on indoor air dry-bulb temperature condition.

B = Capacity compensation value based on outdoor air wet-bulb temperature condition.

C = Capacity modification value under airflow variation rate of indoor unit group (only for duct units).

D = Capacity compensation suitable for total capability of indoor unit group (%).

E = Capacity compensation value based on pipe length, pipe diameter, and height drop.

F = Capacity compensation value for defrost capability of outdoor heat exchanger.

Refer to the performance curves in the manual for the specific values of A, B, C, D, E, and F based on your operating conditions and installation specifics.

Note: The main pipe diameter should be enlarged one size if the single way pipe length is over 90m. Compensation factors should be adjusted for vertical height drops based on the provided table if outdoor is higher than indoor in heating mode.

Adjustment Factor for Vertical Height Drop (Heating Mode – Outdoor Higher than Indoor)

Correction factors adjust the rated capacity based on the single pipe length from the farthest outdoor unit to the farthest indoor unit and the vertical height difference (drop) between them. Separate tables are provided for cooling and heating modes.

Cooling Correction Factor Table:

Heating Correction Factor Table:

The unit should be operated within the following temperature ranges:

Cooling Mode:

• Outdoor Temperature (Dry Bulb): -5°C to 48°C

• Indoor Temperature (Wet Bulb): 15°C to 30°C (Continuous operation range)

Heating Mode:

• Outdoor Temperature (Wet Bulb): -20°C to 27°C

• Indoor Temperature (Dry Bulb): 10°C to 30°C (Continuous operation range)

Operating the unit outside these ranges may trigger protection devices.

WARNINGS (Risk of serious injury or death):

• Installation or maintenance must be performed by an authorized agency. Non-specialized operation can cause water leakage, electric shock, or fire.

• Follow the manual strictly during installation to prevent water leakage, electric shock, or fire.

• Install the unit on a structure capable of bearing its weight to prevent it from falling and causing injury.

• Ensure installation defends against typhoons, earthquakes, etc., as abnormal installation can cause the unit to fall.

• Use the correct specified cables and ensure reliable earthing. Secure terminals firmly; loose connections cause overheating and fire.

• Ensure wiring is properly arranged and not raised or pinched by covers. Incorrect installation can cause heating and fire.

• Do not introduce air or any gas other than R410A into the refrigerant system. Gas mixtures cause abnormally high pressure, leading to rupture or injury.

• Use only specified accessories or parts during installation to prevent water leakage, electric shock, fire, or refrigerant leaks.

• Do not drain water into drainage grooves containing poisonous gases (like sulphur) as the gas can enter the indoor space.

• If refrigerant leakage occurs during or after installation, ventilate the area immediately. Refrigerant can produce poisonous gas upon contact with fire.

• Do not install the unit where flammable gas leakage might occur. Leaked gas accumulating around the unit can cause a fire.

• Install the drainage pipe according to the manual for fluent drainage and provide heat insulation to prevent dew condensation. Improper installation causes water leakage and property damage.

• If the supply cord is damaged, it must be replaced by the manufacturer, service agent, or similarly qualified persons.

• This appliance is not for use by persons with reduced capabilities unless supervised.

• Children aged 8+ and persons with reduced capabilities can use the appliance if supervised/instructed on safe use and hazards.

• Children shall not play with the appliance. Cleaning/maintenance shall not be done by unsupervised children.

• Do not operate via external timers or separate remote controls.

• Keep the appliance and cord away from children under 8 years.

• If transferring the unit, transfer this manual with it.

• Electrify the unit for over 12 hours before startup to protect the compressor. If unused for a long time, cut power.

CAUTIONS (Risk of injury or property damage):

• Earth the unit correctly. Do not connect the earth wire to gas pipes, water pipes, lightning rods, or telephone earth wires. Improper earthing causes electric shock.

• Do not install where flammable gas leaks might occur, to prevent fire.

• Install the water drainage pipe correctly to prevent water leakage and damage.

• Ensure the outdoor fan discharge does not directly blow on plants or flowers.

• Ensure sufficient maintenance space is available.

• When installing on a roof or high place, provide fixed ladders and railings for safety.

• Use two spanners to tighten flare nuts to the correct torque. Over-tightening can break the flare section, causing refrigerant leakage and potential oxygen deficiency.

• Insulate refrigerant pipes to prevent condensation and water damage.

• After piping work, perform a leakage test using nitrogen. Refrigerant leaks in small rooms exceeding concentration limits can cause oxygen deficiency.

• Use only R410A refrigerant. Do not mix refrigerants. R410A pressure is ~1.6 times higher than R22.

• Use R410A specific tools (manifold, hose, flare tool, torque spanner, vacuum pump adapter, leak detector). Charge refrigerant in liquid state from the tank.

• Provide heat insulation for both liquid and gas pipes to prevent condensation.

Note: When charging refrigerant, it must be taken out as liquid state from the tank.

1. Confirm if the model, power supply, pipe, wires, and parts purchased are correct.

2. Check if the indoor and outdoor units can be combined based on the following compatibility:

Additionally, verify:

• If the connected units quantity and the total capacity are within the allowable range.

• If the refrigerant pipe length is within the limited range.

• If the pipe size is proper and installed horizontally (where required).

• If the branch pipe is installed correctly (horizontally or vertically).

• If the additional refrigerant is counted correctly and weighed.

• If there is any refrigerant leakage.

• If all indoor power supplies can be switched on/off simultaneously.

• If the power voltage complies with the rating label.

• If the addresses of indoors have been set.

General Location Requirements:

• Place in a well-ventilated and dry location.

• Ensure noise and exhaust do not affect neighbors and ventilation is unobstructed.

• Ground must be steady, reliable, and strong enough to support the unit’s weight to prevent vibration and noise.

• Allow sufficient space for handling and maintenance as shown in the diagrams.

• Install in a publicly unapproachable place.

Locations to Avoid:

• Places with inflammable gas (risk of fire).

• Places with high oil content, salt spray, or harmful gases (e.g., spa areas, seaside).

• Areas subject to strong coal smoke.

• Places with high humidity.

• Locations near devices emitting Hertzian waves (keep at least 3 meters away from electromagnetic radiation sources).

• Dusty or polluted places that could jam the heat exchanger.

• Areas where voltage changes greatly.

• Where cold/hot air or noise will interfere with neighbors.

• Where other heat sources will affect the unit.

Additional Considerations:

• Ensure water can drain fluently.

• In snowy areas, provide protection (e.g., snow cover) to prevent clogging.

• Install anti-vibration rubber between the unit and bracket/foundation.

• Install in the shade, avoiding direct sunlight or high-temperature heat sources.

• Refer to diagrams for specific minimum clearance distances based on single/multi-unit installations and surrounding obstacles.

• Move the unit to the installation location as close as possible before opening the packaging.

• Do not place anything on top of the equipment.

• Use 2 ropes when hoisting the outdoor unit.

• Hoist the unit levelly and slowly.

• Do not remove the packaging during hoisting.

• Avoid tying the elevator ropes in a way that hits the unit packaging or wrapping.

• Use suitable protection when hoisting the exterior.

• Before installation, do not deposit any material near the outdoor unit location to avoid fire hazards.

• Do not demolish the wooden foundation during handling.

• Prevent the outdoor unit from inclining.

• Handling should be done by more than two people.

• Use the designated handle points as shown in the manual diagram.

General Method:

• Keep pipes as short as possible for efficiency.

• Daub refrigerant oil (ester oil for R410A) on the connector and flare nut.

• When bending pipes, use the largest possible semi-diameter (over 4 times pipe diameter) to avoid breakage.

• Align pipe centers, thread the nut by hand, then tighten with double spanners to the specified torque.

• Prevent impurities (sand, water) from entering the pipe. Use anti-fouling measures (clean pipe, flatten end, seal). Flat the pipe end or seal with adhesive tape depending on storage duration before installation.

Installation Cautions:

• When welding with hard solder, charge nitrogen (0.02MPa gauge pressure) into the pipe to prevent oxidation. Oxide film can clog capillaries/expansion valves.

• Ensure pipes are clean. If impurities enter, clean by flowing nitrogen (approx. 0.5MPa) through the pipe, stopping the ends intermittently.

• Install piping after stop valves are closed.

• Cool valves with a wet towel when welding near them.

• Use special shears, not a saw, to cut pipes.

• Use phosphor copper welding rod without flux for copper pipe welding. Flux (especially chlorine/fluorine containing) damages piping and refrigeration oil.

Material and Specs:

• Use phosphoric oxidize seamless copper pipe: C1220T-1/2H (diameter > 19.05mm); C1220T-0 (diameter ≤ 15.88mm).

• Confirm pipe thickness and specs based on selection method. For R410A, pipes over 19.05mm must be 1/2H type and meet minimum thickness requirements.

• Branch pipes and gather pipes must be manufacturer-specified.

• Install pipes within the allowable length/drop range.

Pipe diameters depend on the location in the system and the connected capacity:

• Pipe “a” (Between indoor unit and branch pipe): Diameter depends on the specific indoor unit’s gas and liquid pipe requirements (refer to indoor unit installation manual).

• Pipe “b” (Between branch pipes): Diameter depends on the total indoor capacity downstream from that pipe section.

Note: If the total indoor capacity after pipe ‘b’ is less than 14.0kW, use the same specs as pipe ‘a’. Adjust diameter on field if needed.

• Pipe “c” (Main pipe between outdoor unit gather pipe and first branch pipe):

Note: Enlarge the main pipe diameter if the distance from the outdoor unit to the longest indoor unit is over 90m.

• Copper Pipe Material Selection:

Pipe Flare Torque Specifications:

Branch Pipe Selection:

The master unit (main outdoor unit) will choose the closest model to the 1st branch pipe.

Installation Notes:

1. Pay attention to the outdoor unit pipe dimensions when connecting the outdoor branch pipe.

2. Diameter adjustments between outdoor branch pipes or between units must be executed at the branch pipe side.

3. Install the outdoor branch pipe (gas/liquid side) horizontally or vertically.

4. When welding with hard solder, blow nitrogen through the pipe to prevent oxidation, which can cause heavy damage. Protect the pipe from water and dust by making the brim as an outer roll.

5. Prepare the pipe end on field, cut off the pipe with a cutter (cut off at the middle), ensure it is horizontal, seal the connection, and wrap with heat insulator and adhesive tape.

General Pipe Installation:

• Avoid collision between pipes and unit parts.

• Close valves fully when connecting pipes.

• Protect pipe ends from water and impurities (weld flat or seal with tape).

• Bend pipes with a large semi-diameter (over 4x pipe diameter).

Pipe Expansion (for flared connections, e.g., outdoor liquid pipe):

• Use a special tool for R410A.

• Install the expanding nut first.

• Adjust projecting pipe length using a copper pipe gauge if needed.

• Use ester oil (not mineral oil) as expanding oil.

• Refer to the table for correct expansion dimension ‘A’ and projecting length ‘B’.

• After expansion, fasten the flare connection using a double-spanner to the correct torque.

Brazing (for outdoor gas pipe, distributing pipes, branch pipes):

• Braze with hard solder.

• During brazing, charge nitrogen through the pipe to prevent oxidation (impurity film) which can clog components and cause failure.

• Seal the pipe end with tape or a stopper to increase resistance while flowing nitrogen.

• Only use nitrogen gas for purging during brazing.

1. The outdoor unit is factory tested. Test the field-installed piping individually; do not test after connecting to the unit’s stop valves.

2. Connect a gauge manifold and nitrogen cylinder to both the gas and liquid service ports (ensure valves are closed).

3. Pressurize step-by-step using dry nitrogen only (do not use oxygen, chlorine, or flammable gas):

a. Apply 0.5MPa (approx. 73 psi) for > 5 minutes. Check for pressure drop.

b. Apply 1.5MPa (approx. 218 psi) for > 5 minutes. Check for pressure drop.

c. Apply the target pressure of 4.15MPa (approx. 602 psi). Record the pressure and ambient temperature.

d. Leave pressurized at 4.15MPa for at least 1 day (24 hours). If the pressure does not drop (after correcting for temperature changes), the test is passed. Note: Pressure changes approx. 0.01MPa per 1°C temperature change.

e. If pressure drops at any stage, there is a leak. Use soapy water or a suitable leak detector to find the leak (check brazing points, flared connections). Repair the leak and repeat the test from step ‘a’.

4. After a successful leakage test, release the nitrogen pressure and proceed to evacuation.

1. Connect a vacuum pump via a gauge manifold to the service ports on both the liquid and gas stop valves.

2. Evacuate the system (including piping and potentially the oil equalization pipe if applicable).

3. Run the vacuum pump until the pressure reaches -100.7 KPa (below -755 mmHg or approx. 29.75 inHg vacuum) or less.

4. Continue running the vacuum pump for at least 1 hour after reaching this vacuum level.

5. Close the manifold valves and stop the vacuum pump.

6. Leave the system for over 1 hour and check if the vacuum pointer on the gauge rises.

7. If the vacuum pointer rises, it indicates moisture or a leak in the system. Check for leaks again and re-evacuate. If no leaks are found, moisture is present, continue evacuation for longer.

8. If the vacuum holds steady for over 1 hour, evacuation is complete.

Open/Close Method:

1. Remove the valve cap.

2. Use a hexangular spanner (Allen key) to turn the valve stem.

3. Turn counter-clockwise fully to open the valve until it stops. Do not apply excessive force once open.

4. Turn clockwise fully to close the valve.

5. Replace and tighten the valve cap securely after operation.

Tightening Torques:

1. The unit comes factory charged (W1), requires an on-site charge (W2 – usually 0kg for these models based on the table), and additional charge based on liquid line length (W3).

2. Calculate the additional refrigerant volume (W3) based on the installed liquid pipe lengths and diameters:

W3 = (L1 × 0.35) + (L2 × 0.25) + (L3 × 0.17) + (L4 × 0.11) + (L5 × 0.054) + (L6 × 0.022)

Where L1 to L6 are the lengths (m) of liquid pipes with diameters Ø22.22, Ø19.05, Ø15.88, Ø12.7, Ø9.52, and Ø6.35 mm respectively. Use the table below for per-meter values:

3. Total refrigerant needed on site = W2 + W3.

4. Total refrigerant in system = W1 + W2 + W3.

5. Charge the calculated additional refrigerant (W3) using a charging scale and manifold gauge.

6. Important R410A Precautions:

• Charge refrigerant in liquid state from the R410A cylinder (typically pink).

• Use dedicated R410A tools (manifold, hoses).

• Do not use a charging cylinder as R410A composition can change.

• Use an anti-counter-flow adapter to prevent compressor oil from entering the refrigerant cycle.

7. If the full additional charge cannot be added while the unit is stopped, add the remaining amount during trial operation mode.

8. Complete charging within 30 minutes if the unit is running.

9. Record the total charged amount (W1+W2+W3) on the label for maintenance purposes.

10. Running the unit with insufficient refrigerant for a long period will cause compressor failure.

• Both gas pipe and liquid pipe must be heat insulated separately.

• Material for the gas pipe insulation must withstand temperatures over 120°C.

• Material for the liquid pipe insulation must withstand temperatures over 70°C.

• Insulation thickness should be over 10mm. If ambient temperature is 30°C and relative humidity is over 80%, the thickness should be over 20mm to prevent condensation.

• Apply the insulation material closely to the pipe without gaps.

• Wrap the insulation securely with adhesive tape.

• Keep connection wires separate from the heat insulation material (at least 20cm away).

• Refrigerant pipes vibrate and expand/shrink during operation.

• Fix the pipe securely at intervals of every 2-3 meters to prevent central stress concentrating in one area, which could cause the pipe to break.

• Outdoor and all indoor units are connected in parallel using 2 non-polar wires (terminals P and Q).

• The ground wire of the outdoor unit must pass through the buckle magnetic ring.

• The shielding layer of the communication wire must be connected together and earthed at a single point (usually at the outdoor unit).

• Total communication wire length cannot exceed 1000m.

• Use 2-core x (0.75-2.0mm²) shielded wire between outdoor/indoor units and between indoor units.

Wired Controller Connection:

• Use 0.75mm² × 3 core shielding line for wired controllers, with a maximum length of 250m.

• The shielding layer must be grounded at one end.

• Connection methods:

1. 1 to Multi (Group Control): One wired controller controls 2-19 indoors. Connect the controller to the designated master indoor unit via 3 polar wires (A, B, C). Connect other slave indoors to the master indoor via 2 or 3 polar wires (AC indoors use B, C; DC indoors use A, B, C* – refer to indoor manual). Indoor 5 in the diagram is the master.

2. 1 to 1: One wired controller controls one indoor unit. Connect via 3 polar wires (A, B, C). Indoors 6-18 in the diagram.

3. 2 to 1: Two wired controllers control one indoor unit. Set one as master, one as slave. Connect both controllers and the indoor unit via 3 polar wires (A, B, C). Indoor 19 in the diagram.

• *Note: If using a remote controller, terminals A, B, C on the signal block may not need wires; consult the specific controller/indoor unit table.

• Ensure input voltage is no less than 380V when running; lower voltage may cause abnormal operation.

• Pass the communication line shielding layer of the outdoor unit through the buckle magnetic ring.

• Outdoor unit power source: 3N~, 380-415V, 50/60Hz.

• Indoor unit power source: 1PH, 220-240V~, 50/60Hz.

• Indoor and outdoor units must use their individual power sources. All indoor units should use one common power source.

• Must install a leakage breaker (Ground Fault Interrupter) and an overcurrent breaker for each power source. Failure to do so may cause electric shock.

• Power cables must be fixed firmly.

• Each outdoor unit must be earthed well.

• If power cable length exceeds the specified range, thicken the cable appropriately.

Outdoor Power Source and Cable Specifications:

Indoor Power Source and Communication Wiring Specifications:

5-Minute Delay Function:

• After powering off and restarting the unit, the compressor has a built-in delay and will run approximately 5 minutes later to protect itself.

Cooling/Heating Operation:

• Indoor units can be controlled individually.

• Units cannot run in Cool and Heat modes simultaneously within the same system. If modes conflict, the unit set later will enter standby, and the unit set earlier will continue to run.

• If an A/C manager fixes the system mode (Cooling or Heating), units cannot operate in the other mode.

Heating Mode Characteristics:

• If the outdoor temperature rises significantly during heating operation, the indoor fan motor may switch to low speed or stop temporarily.

Defrosting in Heating Mode:

• Outdoor unit defrosting is necessary in heating mode and affects heating efficiency temporarily.

• The unit defrosts automatically for about 2-10 minutes when required.

• During defrost, condensate water will flow from the outdoor unit, and vapour may appear, which is normal.

• The indoor fan motor will run at low speed or stop during defrost. The outdoor fan motor will also stop.

Unit Operation Condition:

• Operate the unit within the allowed temperature and humidity ranges specified in the manual. Operating outside these ranges may trigger protection devices.

• Relative humidity should be lower than 80%. Running the unit continuously with humidity over 80% can lead to dew formation on the unit and potentially dripping water from the air outlet.

Note: BM1 settings related to model capacity (BM1-3 to BM1-7) must be set correctly on site according to the specific outdoor unit model.

The outdoor unit has a digital display and four buttons (SW4: Query, SW5: Increase, SW6: Decrease, SW7: Confirm) for checking parameters and making settings.

Querying Parameters:

1. Press SW4 (Query). The display shows “0”.

2. Use SW5 (Increase) or SW6 (Decrease) to select the parameter code you want to query (e.g., “1” for T1 indoor ambient temp, “2” for T2 indoor coil temp, etc. – refer to the manual table for full list).

3. Press SW7 (Confirm). The display shows the value of the selected parameter.

4. Press SW4 (Query) to return to the parameter code selection, or wait 20 seconds for it to exit automatically.

Setting Parameters (Password Required):

1. Press SW4 (Query). Display shows “0”.

2. Press SW7 (Confirm). Display shows “P 0”.

3. Press SW7 (Confirm) again. Display shows “0”.

4. Use SW5/SW6 to enter the password (default: 66). Press SW7 to confirm each digit.

5. After correct password entry, display shows “P –“.

6. Press SW4 (Query). Display shows “0”.

7. Use SW5/SW6 to select the parameter code to set (e.g., “60” for outdoor unit address, “61” for indoor unit quantity – refer to manual table).

8. Press SW7 (Confirm). The display shows the current value of the parameter.

9. Use SW5/SW6 to change the value to the desired setting.

10. Press SW7 (Confirm) to save the new setting. Display shows “P –“.

11. Press SW4 (Query) twice to exit the setting state.

Example: Setting Outdoor Unit Address to 1

SW4 -> SW7 -> SW7 -> SW5 (to 6) -> SW7 -> SW5 (to 6) -> SW7 (Password OK, shows “P –“) -> SW4 -> SW5 (to 60) -> SW7 (Shows current address, e.g., “0”) -> SW5 (to 1) -> SW7 (Setting saved, shows “P –“) -> SW4 -> SW4 (Exit).

Refer to the manual for the complete list of queryable (0-51) and settable (60-81) parameter codes and their meanings.

Startup Control:

• Ensures prerequisites are met (e.g., no critical errors, 5-minute delay passed).

• Starts at a low frequency and gradually increases based on system demand and stability.

• Includes oil return logic during startup if needed.

Output Control (Frequency Adjustment):

• The compressor’s running frequency is adjusted based on the difference between the target evaporation temperature (Te) or condensation temperature (Tc) and the actual temperatures derived from sensors.

• Target Te/Tc is determined by indoor unit settings and outdoor ambient conditions.

• Frequency is increased or decreased within operational limits (minimum/maximum frequency) to meet the cooling or heating load efficiently while maintaining stable operation.

• PID control is used for precise adjustments based on pressure sensor readings and temperature targets.

Defrosting operates only during heating mode to remove ice buildup on the outdoor coil.

Conditions to Enter Defrost:

• The system must be running in heating mode.

• The outdoor coil temperature (T3/Tdef sensor) drops below a certain threshold, indicating potential frost formation.

• A timer condition is met (defrost won’t occur too frequently).

• Intelligent defrost logic compares the change in low pressure and defrost temperature sensor readings to determine the actual frosting degree before initiating defrost.

Defrosting Process:

• The 4-way valve switches (reversing the refrigerant cycle temporarily, similar to cooling mode).

• The indoor fan stops or runs at very low speed.

• The outdoor fan stops.

• The compressor runs to circulate hot gas through the outdoor coil, melting the frost.

Conditions to Exit Defrost:

• The outdoor coil temperature (T3/Tdef) rises above a set point, indicating frost has cleared.

• OR, a maximum defrost time limit (typically 10-12 minutes) is reached.

After Defrost:

• The 4-way valve switches back to heating mode.

• The outdoor and indoor fans resume normal heating operation.

Oil return control ensures sufficient lubricating oil returns to the compressor, especially during prolonged low-load operation or in systems with long piping.

Conditions to Initiate Oil Return:

• The system detects conditions conducive to poor oil return, such as:

• Compressor running continuously for a long duration (e.g., several hours).

• Operating at low frequencies for extended periods.

• Specific temperature or pressure conditions indicating oil might be trapped in the system.

• Some systems may have a timed oil return cycle (e.g., every 8 hours of cumulative compressor run time).

• Enhanced oil return mode can be selected via Dip Switch BM1-8 if standard oil return is insufficient.

Oil Return Process:

• The system temporarily adjusts operating parameters to increase refrigerant velocity and encourage oil flow back to the compressor.

• This may involve briefly increasing compressor frequency and potentially adjusting valve positions.

• The oil return cycle runs for a predetermined duration (typically a few minutes).

Completion:

• After the cycle duration, the system returns to normal operation based on the current demand.

Note: This list combines common VRF codes; specific codes may vary slightly. Refer to the display on the unit and detailed troubleshooting section.

1. Unit Cannot Start At All

• Checkpoints: Power supply off? Power plug loose? Breaker tripped? Voltage abnormal? Timer set correctly? Controller ON?

• Solution: Turn power on, secure plug, reset breaker, check voltage, check timer settings, turn controller on.

2. Insufficient Cooling/Heating

• Checkpoints: Temperature setting appropriate? Air filter dirty? Doors/windows open? Air inlet/outlet blocked? Fan speed too low? Outdoor unit heat exchanger dirty/blocked? System in defrost mode (heating)? Refrigerant level correct?

• Solution: Adjust set temperature, clean filter, close doors/windows, remove obstructions, increase fan speed, clean outdoor unit, wait for defrost to finish, check refrigerant charge (professional needed).

3. Water Leaks from Indoor Unit

• Checkpoints: Unit tilted? Drain hose blocked or improperly installed? Humidity too high (>80%)?

• Solution: Level the unit, clear/reinstall drain hose, reduce humidity if possible.

4. Water Leaks from Outdoor Unit

• Checkpoints: Normal condensation during cooling? Normal meltwater during defrost (heating)?

• Solution: Usually normal, ensure proper drainage if needed.

5. Abnormal Noise

• Checkpoints: Unit installed securely? Foreign objects inside? Fan blades hitting something? Refrigerant flow sounds (gurgling)? Expansion/contraction sounds?

• Solution: Secure installation, remove foreign objects, check fan clearance. Flow/expansion sounds are often normal.

6. Unit Emits Odor

• Checkpoints: Air filter dirty? Odor source in the room being circulated?

• Solution: Clean filter, eliminate room odor source.

7. Remote Control Not Working / Display Dim

• Checkpoints: Batteries dead/incorrectly installed? Distance/angle to unit correct? Obstructions between remote and unit? Strong light interference (fluorescent)?

• Solution: Replace/reinstall batteries, check distance/angle/obstructions, turn off interfering lights.

8. Mist from Air Outlet

• Checkpoints: Room air cooled rapidly causing condensation?

• Solution: Normal phenomenon, especially in high humidity.

9. Specific Error Code Displayed (e.g., E0, P1, U4)

• Checkpoints: Refer to the Failure Code table in the manual.

• Solution: Follow the cause analysis and corrective actions suggested for the specific code. May require professional service.

Important: If the problem persists after checking these points, or if a serious error code appears, turn off the unit, disconnect power, and contact qualified service personnel. Do not attempt complex repairs yourself.

The high pressure switch is a device which can stop the unit automatically when the unit runs abnormally. When the high pressure switch acts, the cooling/heating mode will stop but the running LED on the wired controller will still be lit. The wired controller will display a failure code.

The protection device will act in the following cases:

• In cooling mode, air outlet and air inlet of the outdoor unit are clogged.

• In heating mode, the indoor filter is sticked with dust; indoor air outlet is clogged.

When the protection device acts, please cut off the power source and re-start up after eliminating the trouble.

When power fails during running, all operations will stop.

After being electrified again:

• If the unit has a re-start up function, it can resume to the state before power off automatically.

• If the unit does not have a re-start up function, it needs to be switched on again manually.

When abnormal occurs in running because of the thunder, the lightning, the interference of car or radio, etc, please cut off the power source. After eliminating the failure, press the “ON/OFF” button to start up the unit.

The heating mode adopts the heat pump type that absorbs outdoor heat energy and releases it into indoor. So if the outdoor temperature goes down, the heating capacity will decrease.

Before trial operation:

• Before being energized, measure the resistor between power terminal block (live wire and neutral wire) and the grounded point with a multimeter, and check if it is over 1MΩ. If not, the unit cannot operate.

• To protect the compressor, energize the outdoor unit for at least 12 hours before the unit runs. If the crankcase heater is not energized for 6 hours, the compressor will not work. Confirm the compressor bottom is getting hot.

• Except for the condition that there is only one master unit connected (no slave unit), under the other conditions, open fully the outdoor operating valves (gas side, liquid side, oil equalization pipe). If operating the unit without opening the valves, compressor failure will occur.

• Confirm all indoor units are being electrified. If not, water leakage will occur.

• Measure the system pressure with pressure gauge, at the same time, operate the unit.

In trial operation, refer to the information of the performance section.

When the unit cannot start up at the room temperature, make trial operation for the outdoor unit.

The BM1 dip switch settings introduction:

Note: System cannot operate without locking, and cannot operate when the locking number is not in accordance with the actual quantity.

Key operations:

• Long press ENTER (SW7) 3 seconds to enter dial parameter selection.

• Short press ENTER (SW7) switch edit mode.

• Short press EXIT (SW6) exit.

• Long press ENTER (SW7) 3 seconds to enter parameter view or modify mode.

• Short press UP (SW4) data increase.

• Short press DOWN (SW5) data decrease.

• Short press SW6 exit parameter view or modify mode.

Display parts:

• LD1, LD2, LD3, LD4: 4 digital tubes from left to right.

• Dial code list display mode: LD1 display “_”.

• Parameter display mode: LD1 display “=”.

You can view the indoor machine 128 sets of parameters: SW1 and SW2 represent the indoor unit address, SW3 range is 3-14 can view the indoor unit parameters.

0~3 of SW1 is used to select the outdoor number. SW3 range of 0, 1, 15, observe the outdoor unit parameters.

(The master unit can display the parameters of the other outdoor unit and the indoor units, while the slave outdoor only displays its own parameters).

Using LD2-LD4 display:

Using LD1-LD4 display:

Set SW1=0, SW2=8, SW3=2.

Press ENTER (SW7) for 3 seconds, into refrigerant recovery, digital tube display “C0” and “low pressure data” alternately flashing, indicate enter the refrigerant recovery operation.

Forced cooling mode, all indoor units open. Do not judge superheat, oil temperature conditions.

After 3 mins, Digital tube shows “C1” and “low pressure data” flashing alternately, indicate manual close the liquid pipe stop valve.

When Ps ≤ 1 kg (0.1MPa), Digital Display C2″, indicate manual close the gas pipe stop valve.

After 5s, the system stops automatically, Digital Display C3″, Power off.

Note: after recovery must cancel the setting or re-power on.

Set SW1=0, SW2=12(C), SW3=2.

Press ENTER (SW7) for 3 seconds, display 1111, indoor valve fully open.

Press EXIT (SW6) for 3 seconds, display —-, cancel the forced control of the indoor unit expansion valve.

• All the indoor unit in cooling (SW1=0, SW2=13(D), SW3=2): Press ENTER (SW7) for 3 seconds, display 1111, open; Press EXIT (SW6) for 3 seconds, —-, close.

• All the indoor unit in heating (SW1=0, SW2=14(E), SW3=2): Press ENTER (SW7) for 3 seconds, display 1111, open; Press EXIT (SW6) for 3 seconds, —-, close.

• Cancel all manual control (running class) (SW1=0, SW2=15(F), SW3=2): Press ENTER (SW7) for 3 seconds, display 1111 cancel; or press EXIT (SW6) for 3 seconds, display 0000, cancel. Remove all manual control (part), all indoor unit close.

Each need to be set separately, setting method:

(1) Press ENTER (SW7) for 3 seconds, enter the setting state, flashing display the current value.

(2) Press UP (SW4) or DOWN (SW5) to adjust parameters.

(3) After the adjustment is completed:

A> In the current state of the code, press the ENTER (SW7) for 3 seconds within the effective setting time, save the current setting value and exit the setting state, stop the flicker display, wait for 5 seconds and then power up again.

B> In the current state of the code, not press ENTER (SW7) or change the dip switch selection, do not save the current set value, exit the setting state, stop flashing display.

Use SW1=15(F), SW3=2, and adjust SW2 to select the parameter. View/Set using LD1-4 display.

Set SW1=6, SW2=15(F), SW3=2.

Operation methods:

• Press ENTER (SW7) for 3 seconds, display 1111, then to quit, or press EXIT (SW6) for 3 seconds, display 0000, then quit the set.

• Cancel items: Movable component control by hand such as compressor, motor, electronic expansion valve (LEV), solenoid valve (SV) and so on (including evacuation and charging; excluding rated operation, compulsory operation, indoor run/stop, etc.)

Use SW1, SW2, and SW3 to select the EE data address. Display with digital tube LD1~4.

• SW1=12(C): Addresses 000H-0FFH. Address calculation: addr=SW2*10H +SW3.

• SW1=13(D): Addresses 100H-1FFH. Location for 100H-13FH: addr=100H + SW2*10H +SW3. Addresses 140H-1FFH is fault information area.

• Data display: hexadecimal display, H represents hexadecimal number.

After receiving the outdoor startup instruction, outdoor open SV1 30 seconds and then standby. When startup, the compressor will keep for 3 min at 45rps (when Ta<40°C) or 3 min at 40rps (when Ta>=40°C).

• In cooling mode, meet running 1min & (Td-CT)≥20°C or Ps≤0.1MPa (or max. running time is 3min), quit the startup control;

• In heating mode, meet running 1min and & (Td-CT)≥20°C or Ps≤0.1MPa (or max. running time is 3min), quit the startup control;

• During startup, the high pressure protection, high exhaust protection and current protection is priority and the low exhaust up frequency protection is shielded.

Compressor Pd/Ps control, control the compressor frequency to output appropriate cooling/heating capacity.

The control at the end of the startup control.

According to the ambient temperature select target Ps automatically:

R value setting: Ta<-5°C, Target Ps: setting value -8°C.

-5°C ≤ Ta < 12°C, Target Ps is the slope value of setting value and (setting value -8°C).

According to the piping length to select target Pd and also according to the ambient temperature select target Pd automatically:

Entering condition (needs Ta≤20°C AND one of the OR conditions below):

• After heating startup 60min

• Last defrosting ~ heating cumulative operation time is more than 60 minutes

• A: Ta≥6°C, Te≤-10°C For 5min continuously

• B: -15≤Ta<6°C, Te≤(5Ta-72)/7 For 5min continuously

• C: -23≤Ta<-15°C, Te≤(Ta-69)/4 For 5min continuously

• D: Tao<-23°C, Te≤-23°C For 5min continuously

• X: During the oil return operation meets the following condition, the cumulative operation time reset:

OR Outdoor Te≥10°C, for 1min continuously

OR Outdoor Te≥15°C, for 10min continuously

During defrosting, four-way valve power off, outdoor fan stop, indoor fan stop, outdoor PMV open to 470pls.

Quit defrosting condition (OR):

• After defrosting operation 10min

• OR Outdoor Te≥15°C, for 1min continuously

• OR Outdoor Te≥20°C, for 30s continuously

• OR Outdoor Te≥30°C, for 5s continuously

• OR Tc ≥ 54°C

Entering condition:

A: In cooling mode

• The master unit compressor cumulative operation time:

OR When load rate < 20%: after 2 hours

OR When load rate ≥ 20%: after 4 hours

• AND After the outdoor unit startup:

AND Load rate ≤ 30%

OR (Load rate > 30% AND Finish the outdoor startup control ~ after 20min)

Note: load rate = Σindoor HP(Thermo ON) / Σindoor HP * 100%

Entering condition:

B: In heating mode

• The master unit compressor cumulative operation time:

OR When load rate < 25%: after 1 hours, 4-way valve doesn't reversing oil return operation

OR 25% ≤ load rate < 50%: after 2 hours, 4-way valve doesn't reversing oil return operation

OR 50% ≤ load rate < 75%: after 4 hours, 4-way valve doesn't reversing oil return operation

• AND After the outdoor unit startup:

AND Load rate ≤ 30%

OR (Load rate > 30% AND Finish the outdoor unit startup control ~ after 20min AND Finish defrosting ~ after 30min)

Note: if load rate ≥ 75% and the outdoor unit output rate ≥ 75% for 10 min, oil return time reset.

1) Oil return in cooling mode, the compressor according to the 75% of maximum frequency control, the outdoor PMV opening angle is 470 pls, the Thermo ON indoor PMV opening angle is 250 pls, the Thermo OFF indoor PMV opening angle is 125 pls.

2) Oil return in heating mode (4-way valve reversing), the compressor according to the 75% of maximum frequency control, the outdoor PMV opening angle is 470 pls, the Thermo ON and Thermo OFF indoor PMV opening angle is 125 pls. When Td > 95 °C and TdSH > 15 °C, the indoor PMV opening angle increased 10%, max. time is 2; When Td < 90 °C, return to the usually opening.

3) Oil return in heating mode (4-way valve doesn’t reversing), the compressor according to the indoor units load rate and current running frequency to confirm the oil return enter frequency, the maximum frequency can’t exceed 75% of the maximum frequency. the PMV of the outdoor and the Thermo ON indoor unit control automatically, Thermo OFF indoor PMV opening angle is 250 pls.

1) In cooling mode:

• OR After 5min

• OR (After 1min AND (Td < CT + 10°C, for 10s continuously OR Ts - ET < 15°C, for 10s continuously))

2) In heating mode (4-way valve reversing):

• OR After 5min

• OR (After 2min AND (Td < CT + 10°C, for 10s continuously OR Ts - ET < 15°C, for 10s continuously))

3) In heating mode (4-way valve doesn’t reversing):

• OR After 5min

• OR Td ≥ 105°C, for 5s continuously

Inverter outdoor unit failure code:

In case of no failure, if the starting conditions of the system are not met, the digital tube of the outdoor unit will display the standby code of the air conditioner:

Follow these steps:

1. Check if the sensor terminal is fixed well. If No, reconnect the terminal. If Yes, proceed to step 2.

2. Check if the sensor resistor/characteristic is proper. If No, replace the sensor. If Yes, proceed to step 3.

3. Check if the PCB is faulty. If Yes, replace the PCB.

Follow these steps:

1. Check if the sensor terminal is fixed well. If No, reconnect the terminal. If Yes, proceed to step 2.

2. Test the voltage between the red terminal and black terminal using a multimeter. Is it 5V? If No, replace the PCB. If Yes, proceed to step 3.

3. Test the voltage between the white terminal and black terminal using a multimeter. Is it between 0.5V and 3.5V? If Yes, replace the pressure sensor. If No, proceed to step 4.

4. Replace the connecting board.

Follow these steps:

1. Check if the wiring between P and Q is wrong or broken down. If Yes, modify the communication wire. If No, proceed to step 2.

2. Check if the wire of CN29 on the outdoor connecting board is normal. If No, modify the port. If Yes, proceed to step 3.

3. Check if the wire of CN15 on the outdoor connecting board is normal. If No, check/fix CN15 wiring. If Yes, proceed to step 4.

4. Check if indoor and outdoor units are electrified at the same time. If No, ensure simultaneous power connection. If Yes, proceed to step 5.

5. Check if the communication wire is separate from high-voltage wire on the layout. If No, change the communication wiring type/route. If Yes, proceed to step 6.

6. Check if the indoor quantity is correct (check by rotary switch). If No, proceed to step 7. If Yes, shut off power supply, and the outdoor unit searches for indoors again.

7. Check if there is a noise source. If Yes, eliminate the noise source. If No, proceed to step 8.

8. Check if the failure disappears after changing the indoor PCB. If No, proceed to step 9.

9. Check the outdoor PCB. If faulty, replace it.

Follow these steps:

1. Check if the EEPROM is fixed well. If No, reconnect it. If Yes, proceed to step 2.

2. Replace the EEPROM.

Follow these steps:

1. Check if the connection between the 4-way valve and the connecting board is good. If No, re-connect. If Yes, proceed to step 2.

2. Check if the system meets the condition for 4-way valve reversing (Pd-Ps > 0.6MPa). If No, check if SV1 leaks. If Yes, proceed to step 3.

3. Measure if the CN49 voltage on the connecting board is 220VAC after the 4-way valve reversing condition is met. If No, replace the connecting board. If Yes, proceed to step 4.

4. Check if the compressor running current is normal. If No, check the compressor. If Yes, proceed to step 5.

5. Check if there is air noise after the 4-way valve reverses, and if the temperature of connection pipes with the 4-way valve is normal. If No, proceed to step 6.

6. Replace the 4-way valve.

Follow these steps:

1. Check if the connection between the pressure switch and connecting board is good. If No, re-connect. If Yes, proceed to step 2.

2. Check if the system pressure meets the condition that the pressure switch shuts off. If No, replace the pressure switch. If Yes, proceed to step 3.

3. Make the pressure switch close and measure if the terminal is conductive using a multimeter. If No, check switch/measurement. If Yes, proceed to step 4.

4. Check if the system is clogged. If Yes, check the piping system. If No, proceed to step 5.

5. Make the pressure switch terminal on the connecting board short circuit. Check if the failure still exists. If Yes, replace the connecting board. If No, proceed to step 6.

6. Replace the pressure switch and measure again.

Follow these steps:

1. Check if the sensor terminal is fixed well. If No, reconnect. If Yes, proceed to step 2.

2. Check if the sensor resistor/characteristic is proper. If No, replace the sensor. If Yes, proceed to step 3.

3. Check if the system is lacking refrigerant. If Yes, charge refrigerant. If No, proceed to step 4.

4. Replace the connecting board.

Follow these steps:

1. Check if the Toil sensor is fixed well and if its characteristic is correct. If No, fix or replace the sensor. If Yes, proceed to step 2.

2. Check if the terminal of LEVb is fixed well. If No, reconnect. If Yes, proceed to step 3.

3. In cooling mode, when the indoor unit is off, check if the EEV can completely close. If No, replace or adjust the indoor unit EEV. If Yes, proceed to step 4.

4. Check if refrigerant is too much. If Yes, recharge refrigerant (recover excess refrigerant).

Follow these steps:

1. Check if the actual pressure is in conformance with the measured data by the sensor. If No, replace the pressure sensor. If Yes, proceed to step 2.

2. Check if the stop valve is open fully. If No, open the stop valve. If Yes, proceed to step 3.

3. Check if the system is lacking refrigerant. If Yes, recharge refrigerant. If No, proceed to step 4.

4. Check if the terminal of the electronic expansion valve coil is fixed well. If No, re-connect the terminals. If Yes, proceed to step 5.

5. Check if the piping system is clogged. If Yes, clear the piping.

Follow these steps:

1. Check if the actual pressure is in conformance with the measured data by the sensor. If No, replace the pressure sensor. If Yes, proceed to step 2.

2. Check if the compressor running current is normal. If No, check the compressor. If Yes, proceed to step 3.

3. Check if the 4-way valve is interconnected correctly. If No or suspect an issue, replace the 4-way valve.

Follow these steps:

1. Check if the characteristics of the high pressure sensors are normal. If No, replace the pressure sensor. If Yes, proceed to step 2.

2. Check if the stop valve opens fully. If No, open the stop valve. If Yes, proceed to step 3.

3. In cooling mode, check if the outdoor fan motor runs normally. If No, check the fan motor. If Yes, proceed to step 4.

4. In heating mode, check if the indoor fan motor runs normally and if the filter is clogged. If No (motor issue) or Yes (filter clogged), check the indoor unit (fan/filter). If Yes (motor normal) and No (filter not clogged), proceed to step 5.

5. Check if the piping system is clogged. If Yes, clear the piping.

Follow these steps:

1. Check if the sensor characteristic is correct. If No, replace the sensor. If Yes, proceed to step 2.

2. Check if the terminal of the sensor is fixed well. If No, reconnect. If Yes, proceed to step 3.

3. In cooling mode, when the indoor unit is off, check if the EEV can completely close. If No, replace or adjust the indoor unit EEV. If Yes, proceed to step 4.

4. Check if refrigerant is too much. If Yes, recharge refrigerant (recover excess refrigerant).

Follow these steps:

1. Check if the communication wire between the connecting board and module is connected normally. If No, re-connect. If Yes, proceed to step 2.

2. In cooling mode, when the indoor unit is off, check if the EEV can completely close. If No, check/replace/adjust EEV. If Yes, proceed to step 3.

3. Measure if the voltage of CN28 on the connecting board changes using a multimeter. If No, replace the connecting board. If Yes, proceed to step 4.

4. Replace the module.

Follow these steps:

1. Check if the connection between the pressure switch and the connecting board is good. If No, re-connect. If Yes, proceed to step 2.

2. Check if the system pressure meets the condition that the pressure switch shuts off. If Yes and the system lacks refrigerant, recharge the refrigerant. If No or refrigerant level is OK, proceed to step 3.

3. Make the pressure switch terminal on the connecting board short circuit. Check if the failure still exists. If Yes, replace the connecting board. If No, proceed to step 4.

4. Replace the pressure switch.

Follow these steps:

1. Check if the connection between the connecting board and the CT board is connected well (CN9). If No, re-connect. If Yes, proceed to step 2.

2. Check if the CT wire is conductive. If No, replace the wire. If Yes, proceed to step 3.

3. Check if it is normal after replacing the CT board. If No, replace the connecting board. If Yes, the CT board was the issue.

Follow these steps:

1. Check if the wire between the connecting board and module is connected normally. If No, re-connect. If Yes, proceed to step 2.

2. Check if the CT wire is conductive. If No, replace the wire. If Yes, proceed to step 3.

3. Check if the temperature on top of the fixed frequency compressor is too high. If Yes, proceed to step 5. If No, proceed to step 4.

4. Check if the AC contactor works. If No, check contactor. If Yes, check if the system is normal after replacing the CT detector. If Yes, problem solved. If No, replace the PCB.

5. Check if there is air in the system. If Yes, recharge refrigerant (evacuate and recharge). If No, proceed to step 6.

6. Check if the motor is clogged or bad. If Yes, fix the system (motor). If No, proceed to step 7.

7. Replace the compressor.

Follow these steps:

1. Rotate the fan motor by hand to check if there is obvious friction. If Yes, replace the fan motor. If No, proceed to step 2.

2. Check if the motor and PCB connection is well. If No, re-connect. If Yes, proceed to step 3.

3. Force the fan in low speed and measure if it has alternating voltage between FG and GND. If No, replace the motor. If Yes, proceed to step 4.

4. Replace the outdoor PCB.

Follow these steps:

1. Check if the high/low pressure sensor is connected well. If No, re-connect. If Yes, proceed to step 2.

2. Check if the compressor wire is connected normally. If No, correct the compressor wire. If Yes, proceed to step 3.

3. Check if the wires of the inverter compressor are connected oppositely. If Yes, correct the compressor wire. If No, proceed to step 4.

4. Check if the 4-way valve is interconnected correctly. If No or suspect an issue, replace the 4-way valve. If Yes, proceed to step 5.

5. Measure if there is voltage U, V, W of the compressor using a multimeter, and if it is normal. If No, replace the inverter module. If Yes, proceed to step 6.

6. Replace the inverter compressor.

Follow these steps:

1. Check if the wires of the compressor connect well. If No, reconnect or change the wires. If Yes, proceed to step 2.

2. Measure the compressor winding with a milliohm meter. Check if the compressor resistance is balanced. If No, change the compressor. If Yes, proceed to step 3.

3. Check if the high/low pressure is normal. If No (abnormal), investigate the pressure issue. If Yes, proceed to step 4.

4. Change the module.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct, and if the compressor wire is fixed well. If No, correct the wiring according to the diagram. If Yes, proceed to step 3.

3. Check if the power module is normal. If No, replace the power module. If Yes, proceed to step 4.

4. Check if the compressor is normal (compressor coil resistor, insulation). If No, replace the compressor. If Yes, proceed to step 5.

5. Check if there are other failures recently, such as 112, 113, 114. If Yes, solve the failures due to relative information. If No, remove the failure (this might resolve the issue or indicate it was transient).

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wires among U, V, W of the compressor are normal. If No, replace the wires. If Yes, proceed to step 3.

3. Check if the compressor is normal (compressor coil resistor, insulation). If No, replace the compressor. If Yes, proceed to step 4.

4. Compressor load too much, check the reason.

Follow these steps:

1. Check if the temperature sensor characteristic is correct. If No, replace the sensor. If Yes, proceed to step 2.

2. Check if the radiator is blocked. If Yes, clean the radiator. If No, proceed to step 3.

3. Check if the screw of the module is fixed well, and if radiating silica gel is daubed enough and evenly, if there is no dirt on the radiator. If No to any condition, fix it well and daub gel again, clean the radiator. If Yes to all conditions, proceed to step 4.

4. Improve the running environment of the outdoor unit.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct. If No, correct the wiring according to the diagram. If Yes, proceed to step 3.

3. Check if the compressor is normal (compressor coil resistor, insulation). If No, replace the compressor. If Yes, proceed to step 4.

4. Check if the power module is normal. If No, replace the power module. If Yes, proceed to step 5.

5. Compressor load too much, check the reason.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct. If No, correct the wiring according to the diagram. If Yes, proceed to step 3.

3. Check if the AC contactor or relay acts well. If No, adjust or replace the relay. If Yes, proceed to step 4.

4. Measure if the DC bus line voltage between P and N of the module is less than 375V. If No, the circuit of the DC bus line voltage on the inverter control board is abnormal, replace the inverter control board. If Yes, proceed to step 5.

5. Check the rectifier, reactor, electrolytic capacitor in the inverter main circuit.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct. If No, correct the wiring due to diagram. If Yes, proceed to step 3.

3. Measure if the DC bus line voltage between P and N of the module is over 644V. If No, the circuit of the DC bus line voltage on the inverter control board is abnormal, replace the inverter control board. If Yes, proceed to step 4.

4. Check the rectifier, reactor, electrolytic capacitor in the inverter main circuit.

Follow these steps:

1. Check if the wire between the control PCB and inverter board is abnormal. If Yes, adjust the communication wire. If No, proceed to step 2.

2. Check if the communication circuit of the main control PCB is abnormal (if signal LED flashes abnormally). If Yes, replace the main control board. If No, proceed to step 3.

3. Check if the inverter module board is abnormal. If Yes, the detecting circuit on the inverter board is broken down, replace the inverter module board. If No, proceed to step 4.

4. Solve the failures due to relative information.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct. If No, correct the wiring due to diagram. If Yes, proceed to step 3.

3. Check if the compressor is normal (compressor coil resistor, insulation). If No, replace the compressor. If Yes, proceed to step 4.

4. Check if the power module is normal. If No, replace the power module. If Yes, proceed to step 5.

5. Compressor load too much, check the reason.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the power module is normal. If No, replace the power module. If Yes, proceed to step 3.

3. Check if the compressor is normal (compressor coil resistor, insulation). If No, replace the compressor. If Yes, proceed to step 4.

4. Compressor load too much check the reason.

Follow these steps:

1. Check if the wire between DCCT and control board, wire between IPM and compressor are correct; check if the wiring direction of DCCT is normal. If No, correct the wiring according to the diagram. If Yes, proceed to step 2.

2. Check if the current sensor is normal. If No, replace the current sensor. If Yes, proceed to step 3.

3. Replace the inverter PCB.

Follow these steps:

1. Check if the connection between the temp. sensor and inverter board is correct. If No, adjust the connection. If Yes, proceed to step 2.

2. Measure if the temp. sensor resistor is normal. If No, replace the sensor. If Yes, proceed to step 3.

3. Replace the inverter control board.

Follow these steps:

1. Check if the voltage of the power supply is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire of the electric box is correct. If No, correct the wiring due to diagram. If Yes, proceed to step 3.

3. Check if the relay or AC contactor acts well. If No, adjust or replace the relay or AC contactor. If Yes, proceed to step 4.

4. Measure if the DC bus line voltage between P and N on the module is less than 140V. If No, the DC bus line voltage circuit on the inverter board is broken down, replace the inverter module board. If Yes, proceed to step 5.

5. Check the rectifier, reactor, electrolytic capacitor in the inverter main circuit.

Follow these steps:

1. Check if the voltage of the power supply on the inverter control board is normal. If No, improve the power supply circuit. If Yes, proceed to step 2.

2. Check if the wire between the control PCB and inverter board is abnormal. If Yes, adjust the communication wire. If No, proceed to step 3.

3. Check if the circuit of the inverter control board is abnormal. If Yes, replace the power module (or inverter control board based on context). If No, proceed to step 4.

4. Solve the failures due to relative information.

Temp. sensor characteristic:

Typical resistor values for Sensor Type 1 (R25=10ΚΩ±3%, B25/50=3700K±3%):

Typical resistor values for Sensor Type 2 (R25=23ΚΩ±3%, B25/50=4200K±3%):

Typical resistor values for Sensor Type 3 (R80=50ΚΩ±3%, B25/80=4450K±3%):