Inverter Multi-Split System Residential Air-Conditioners

1.1.1 SRK-ZSX series

(1) Operation control function by wireless remote control

SRK20, 25, 35, 50, 60ZSX-W, -WB, -WT

• Operation section:
• OPERATION MODE select button: Changes mode with each press.
• ON/OFF (luminous) button: Press to start, press again to stop.
• TEMPERATURE button: Sets room temperature.
• FAN SPEED button: Changes fan speed with each press.
• HI/ECO button: Switches between HIGH POWER/ECO operation.
• AIR FLOW (UP/DOWN) button: Changes air flow direction (up/down).
• AIR FLOW (LEFT/RIGHT) button: Changes air flow direction (left/right).
• SILENT button: Sets SILENT operation.
• ALLERGEN CLEAR button: Selects ALLERGEN CLEAR operation.
• 3D AUTO button: Sets 3D AUTO operation.
• NIGHT SETBACK button: Sets NIGHT SETBACK operation.
• SET/Child lock button: Used to set timer and Child lock.
• ON TIMER button: Selects ON TIMER operation.
• OFF TIMER button: Selects OFF TIMER operation.
• WEEKLY button: Switches WEEKLY TIMER to ON/OFF.
• CANCEL button: Cancels ON timer, OFF timer, and SLEEP operation.
• TIMER button: Used for setting current time and timer function.
• PROGRAM button: Sets WEEKLY TIMER.
• MENU switch: Selects brightness adjustment, AUTO OFF operation, SELF CLEAN operation, and PRESET operation.
• SLEEP button: Selects SLEEP operation.
• Transmission section:
• Unit display section:
• Wireless remote control signal receiver
• RUN light (green): Illuminates during operation. Blinks slowly during SELF CLEAN (3s ON, 1s OFF). Blinks when airflow stops to prevent cold air blow-out in heating (1.5s ON, 0.5s OFF). Blinks slowly during AUTO OFF standby (3.5s ON, 0.5s OFF).
• TIMER light (yellow): Illuminates during TIMER operation.
• RUN lights blink quickly during invalid operation mode.

Diagram Description: Illustration showing the remote control layout with buttons and display sections.

SRK20, 25, 35, 50, 60ZSX-WF, -WFB, -WFT

• Operation section: (Similar to above, with variations)
• OPERATION MODE select button
• TEMPERATURE button
• HI/ECO button
• AIR FLOW (UP/DOWN) button
• AIR FLOW (LEFT/RIGHT) button
• SILENT button
• 3D AUTO button
• NIGHT SETBACK button
• ALLERGEN CLEAR button
• SET/Child lock button
• ON TIMER button
• OFF TIMER button
• CANCEL button
• TIMER button
• WEEKLY button
• PROGRAM button
• MENU switch: Selects brightness adjustment, AUTO OFF operation, SELF CLEAN operation, Fan control in heating thermo off, Wireless LAN communication setting, Wireless LAN connection setting, and PRESET operation.
• SLEEP button
• Transmission section:
• Unit display section: (Similar to above)
• Wireless remote control signal receiver
• RUN light (green)
• TIMER light (yellow)

Diagram Description: Illustration showing the remote control layout for WF models.

(2) Unit ON/OFF button

Diagram Description: Diagram showing the Unit ON/OFF button on the indoor unit.

This button can be used for turning on/off the unit when a remote control is not available. It operates in COOL or HEAT modes.

(3) Auto restart function

Diagram Description: Diagram illustrating the Auto Restart function, showing jumper wire J170.

Records the operational status of the air-conditioner immediately prior to being switched off by a power cut, and then automatically resumes operations after the power has been restored. Timer settings and HIGH POWER operation are cancelled.

(4) Installing two air-conditioners in the same room

Diagram Description: Diagrams illustrating the procedure for setting the wireless remote control and indoor unit to prevent interference when two air-conditioners are in the same room. This involves disconnecting a switching line on the remote control and using the ACL switch.

Procedure:

1. Setting the wireless remote control:
   • Pull out the cover and take out batteries.
   • Disconnect the switching line next to the battery with wire cutters.
   • Insert batteries. Close the cover.
2. Setting the indoor unit:
   • Turn off the power source, and turn it on after 1 minute.
   • Point the wireless remote control (set as above) at the indoor unit and send a signal by pressing the ACL switch.
   • The signal is sent about 6 seconds after pressing ACL. Keep pointing the remote at the indoor unit.
   • Check for a "Peep" buzzer sound from the indoor unit, indicating successful setting.

(5) Selection of the annual cooling function

Diagram Description: Diagram showing jumper wire J3 and interface kit SW2-4, used to enable/disable annual cooling function.

The annual cooling control is valid from factory default. It can be disabled by cutting jumper wire (J3) or changing DIP switch (SW2-4) on the interface kit (option) PCB.

Content of control:

• If the outdoor air temperature sensor (TH2) detects below 5°C, the indoor unit speed is switched to the 8th step.
• If the outdoor air temperature sensor (TH2) detects higher than 7°C, the indoor unit speed is changed to the normal control speed.

(6) Heating only function

Diagram Description: Diagram showing jumper wire J4, used to enable/disable heating-only function.

Heating only function can be enabled by disconnecting jumper wire (J4). Control contents show that COOL/DRY/FAN modes are changed to HEAT mode.

(7) High power operation

Pressing the HI/ECO button initiates powerful cooling and heating operation for 15 minutes. The remote control displays a HIGH POWER mark. Room temperature is not controlled during this mode. It is not available during DRY and ON timer to OFF timer operations. It cancels if the HI/ECO button is pressed again, operation mode is changed, 15 minutes elapse, 3D AUTO or SILENT or NIGHT SETBACK buttons are pressed. Not operable when the unit is OFF.

(8) Economy operation

Pressing the HI/ECO button initiates a soft operation with suppressed power to avoid excessive cooling or heating. The unit operates 1.5°C higher than setting temperature during cooling or 2.5°C lower during heating. The remote control displays an ECONOMY mark. It enters economy operation at the next run if stopped by ON/OFF, SLEEP, or OFF TIMER. It cancels if HI/ECO is pressed again, mode changes from DRY to FAN, or NIGHT SETBACK is pressed. Not operable when the unit is OFF.

(9) Air flow direction adjustment

Air flow direction can be adjusted using the AIR FLOW (UP/DOWN) and (LEFT/RIGHT) buttons. Flap and louver controls are described with angles and swing/spot/wide modes.

• Flap: Controls up/down direction. Angles vary from approx. 15° to 55° from horizontal depending on mode (COOL/DRY/FAN vs. HEAT) and selection (stopped, swing).
• Louver: Controls left/right direction. Positions include Center, Left, Right, with angles specified for different installation locations. Swing, Spot, Wide modes are available.
• Swing: Flap or louver moves continuously.
• Memory flap: Stops flap/louver at a specific position, which is memorized for future operations.

Diagram Description: Diagrams showing flap and louver positions, angles, and swing motions.

(10) 3D auto operation

During cooling and heating (including auto modes), fan speed, flap, and louver positions are automatically adjusted based on room temperature, setting temperature, and HIGH POWER/AUTO selection. Specific logic is detailed for different temperature differentials and operation modes.

• Cooling/Heating: Logic based on Room temp. vs. Setting temp. (e.g., >5°C, <=5°C).
• DRY operation: Flap is set to horizontal blowing, Louver to wide (fixed).

Diagram Description: Diagrams illustrating the 3D Auto operation logic, showing how flap and louver positions are determined based on temperature differences and operation modes.

(11) Timer operation

• Comfort start-up (ON timer): Unit starts 5-60 minutes before the set time to reach optimum temperature.
• Sleep timer: Temperature is controlled with respect to the set temperature.
• OFF timer: Can be set in 10-minute units within a 24-hour period.
• Weekly timer: Up to 4 programs per day are available.

Diagram Description: Table showing combinations of timer operations that can be set.

Note: Timer operation from wireless remote control is invalid when an interface kit is connected.

(12) Silent operation

When set, the unit operates by dropping outdoor fan speed and compressor speed. Tables show specific speeds for different SCM models.

(13) Night setback operation

When the "Night setback" signal is received, heating operation starts with the setting temperature at 10°C.

(14) Air flow range setting

Diagram Description: Diagrams showing how to set the air flow range (left/right) for different installation locations (Center, Right end, Left end).

Instructions provided to adjust left/right air flow range to maximize air-conditioning, considering the unit's location. Involves pressing specific buttons together for a duration.

(15) Display brightness adjustment

Note: Brightness is always LV2 during self-diagnosis or service mode.

(16) AUTO OFF operation

The air-conditioner automatically stops approximately 1 or 2 hours after the sensor judges no one is in the room, to prevent continued operation. A warning sound is emitted. If a person is detected within 12 hours of stopping, operation resumes. AUTO OFF is disabled during SLEEP TIMER, OFF TIMER, and ON TIMER + OFF TIMER operations. It does not activate if operation starts via ON TIMER when no one is home.

(17) Wireless LAN connection function

Describes conditions for receiving a wireless LAN connection setting signal from a remote control when all units are stopped. Details operation and reset conditions.

(18) Fan control during heating thermostat OFF

Selectable fan controls: Normal thermostat operation, Fireplace, Interval, Stop. Details the "Interval" control logic, which involves fan OFF for 5 minutes, then fan ON at a low tap for 1 minute, repeating.

(19) Outline of dehumidifying (DRY) operation

Diagram Description: Diagram showing Indoor unit fan speed and Compressor speed areas (A, B, C, D) controlled by temperature difference during DRY operation.

Purpose is dehumidification, not humidity control. Indoor fan speed and compressor are controlled by selected areas based on temperature difference. Prevents over-cooling. If outdoor and room temperatures are low, the unit may heat first before starting DRY operation.

(20) Outline of automatic operation

Diagram Description: Diagrams illustrating the determination of operation mode (Cooling/Heating) based on indoor and outdoor air temperatures, and mode switching conditions.

Operation mode is determined by indoor and outdoor air temperatures. Mode changes if cooling/heating thermostat is OFF for 20 minutes and conditions are met. If setting temperature is changed via remote control, mode is judged immediately. Cannot change to heating if outdoor temperature is 28°C or higher. If unit restarts within 1 hour of stopping auto operation, it resumes previous mode. Setting temperature range is specified.

(21) Protective control function

(a) Dew prevention control [Cooling]: Prevents dewing on the indoor unit. Operates if humidity is 68% (or 60% for SRK50, 60) or higher for 30 mins after starting with compressor ON. Controls air capacity and wind direction. Resets when humidity drops below 63% (or 55% for SRK50, 60) or compressor is OFF.

(b) Frost prevention control: Prevents frosting. Details operating conditions, anti-frost operation (compressor speed reduction, fan/valve control), and reset conditions based on indoor heat exchanger temperature.

Diagram Description: Diagrams showing compressor speed reduction and indoor heat exchanger temperature thresholds for frost prevention.

(c) Cooling overload protective control: Prevents anomalous high pressure during cooling. Operates when outdoor air temperature (TH2) is 38°C or more (or 41°C/47°C for specific models) for 30 seconds with compressor running. Adjusts compressor speed limits. Resets at 37°C (or 40°C for specific models).

Diagram Description: Diagrams showing compressor speed adjustment based on outdoor air temperature and heat exchanger temperature.

(d) Cooling high pressure control: Prevents anomalous high pressure operation during cooling. Detects outdoor heat exchanger sensor (TH1). Details compressor speed reduction based on outdoor heat exchanger temperature and outdoor air temperature.

Diagram Description: Diagrams showing compressor speed reduction based on outdoor heat exchanger temperature and outdoor air temperature.

1.1.2 SRK-ZS series

(1) Operation control function by wireless remote control

SRK20, 25, 35, 50ZS-W, -WB, -WT

• Operation section: (Similar to SRK-ZSX, with slight variations in button functions like MENU switch options)
• Transmission section:
• Unit display section:

Diagram Description: Illustration showing the remote control layout for SRK-ZS series.

SRK20, 25, 35, 50ZS-WF, -WFB, -WFT

• Operation section: (Similar to SRK-ZS, with WF model variations in MENU switch options)
• Transmission section:
• Unit display section:

Diagram Description: Illustration showing the remote control layout for SRK-ZS WF models.

(2) Unit ON/OFF button

Diagram Description: Diagram showing the Unit ON/OFF button on the indoor unit.

Can be used when the remote control is unavailable. Operates in COOL, DRY, or HEAT modes.

(3) Auto restart function

Diagram Description: Diagram illustrating the Auto Restart function, showing jumper wire J170.

Records operational status before power cut and resumes automatically. Timer settings and HIGH POWER operation are cancelled.

(4) Installing two air-conditioners in the same room

Diagram Description: Diagrams illustrating the procedure for setting the wireless remote control and indoor unit to prevent interference.

Similar procedure to SRK-ZSX series: disconnect switching line on remote, use ACL switch, power cycle indoor unit.

(5) Selection of the annual cooling function

Diagram Description: Diagram showing jumper wire J3 and interface kit SW2-4.

Annual cooling control is enabled by default. Can be disabled by cutting J3 or changing SW2-4. Control logic based on outdoor air temperature (below 5°C triggers 7th step fan speed, above 10°C returns to normal).

(6) Heating only function

Diagram Description: Diagram showing jumper wire J4.

Enabled by disconnecting J4. Changes COOL/DRY/FAN to HEAT mode.

(7) High power operation

Initiates powerful cooling/heating for 15 minutes. Displays HIGH POWER mark. Not controlled by room temperature. Not available during DRY and timer operations. Cancels under specific conditions. Not operable when unit is OFF.

(8) Economy operation

Initiates soft operation to avoid excessive cooling/heating. Operates 1.5°C higher (cooling) or 2.5°C lower (heating) than set temperature. Displays ECONOMY mark. Cancels under specific conditions. Not operable when unit is OFF.

(9) Air flow direction adjustment

Adjustable via AIR FLOW buttons. Flap angles range from approx. 25° to 70° depending on mode. Louver control includes swing, spot, wide modes. Memory flap function available.

Diagram Description: Diagrams showing flap and louver positions, angles, and swing motions for SRK-ZS series.

(10) 3D auto operation

Automatic adjustment of fan speed, flap, and louver based on temperature differences and operation modes (Cooling, Heating, DRY). Specific logic detailed for various conditions.

Diagram Description: Diagrams illustrating the 3D Auto operation logic for SRK-ZS series.

(11) Timer operation

Includes Comfort start-up (ON timer), Sleep timer, OFF timer, and Weekly timer. Timer combinations and priority rules are described.

Diagram Description: Table showing timer operation combinations.

Note: Timer operation from wireless remote control is invalid with interface kit.

(12) Silent operation

Reduces outdoor fan and compressor speeds. Tables show specific speeds for different SCM models.

(13) Night setback operation

Heating operation starts with setting temperature at 10°C upon receiving the "Night setback" signal.

(14) Air flow range setting

Diagram Description: Diagrams showing how to set air flow range for different installation locations.

Instructions to adjust left/right air flow range using specific button combinations.

(15) Display brightness adjustment

(16) Wireless LAN connection function

Describes conditions for wireless LAN connection setting, operation details, and reset conditions.

(17) Fan control during heating thermostat OFF

Selectable fan controls: Normal, Fireplace, Interval, Stop. Details the "Interval" control logic.

(18) Outline of dehumidifying (DRY) operation

Diagram Description: Diagram showing fan speed and compressor areas for DRY operation.

Purpose is dehumidification. Controls fan speed and compressor based on temperature difference. Prevents over-cooling. May heat first if temperatures are low.

(19) Outline of automatic operation

Diagram Description: Diagrams showing automatic operation mode determination based on temperatures.

Mode determined by indoor/outdoor air temperatures. Mode changes under specific conditions. Setting temperature range is specified. Cooling operation controlled by display temps, heating temp compensated by +2°C with wired remote.

(20) Protective control function

(a) Dew prevention control: Prevents dewing. Operates if humidity is 68% or higher for 30 mins. Controls air capacity and wind direction. Resets when humidity drops or compressor is OFF.

(b) Frost prevention control: Prevents frosting. Details conditions, operation (compressor speed reduction, fan/valve control), and reset based on indoor heat exchanger temperature.

Diagram Description: Diagrams for frost prevention control.

(c) Cooling overload protective control: Prevents high pressure. Operates based on outdoor air temperature. Adjusts compressor speed limits.

Diagram Description: Diagrams for cooling overload protection.

(d) Cooling high pressure control: Prevents high pressure. Details compressor speed reduction based on outdoor heat exchanger and air temperatures.

Diagram Description: Diagrams for cooling high pressure control.

1.1.3 SRK-ZR series

(1) Operation control function by wireless remote control

SRK71, 80ZR-W

• Operation section: (Similar to other SRK series, with specific buttons like CLEAN switch, HI POWER light)
• Transmission section:
• Unit display section: RUN (HOT KEEP) light, TIMER light, HI POWER light, 3D AUTO light.

Diagram Description: Illustration showing the remote control layout for SRK-ZR series.

SRK71, 80ZR-WF

• Operation section: (Similar to SRK-ZR, with WF model variations)
• Transmission section:
• Unit display section:

Diagram Description: Illustration showing the remote control layout for SRK-ZR WF models.

(2) Unit ON/OFF button

Diagram Description: Diagram showing the Unit ON/OFF button.

Can be used when remote control is unavailable. Operates in COOL, DRY, HEAT modes.

(3) Auto restart function

Diagram Description: Diagram showing jumper wire JA1.

Records status before power cut and resumes automatically. Timer settings and HIGH POWER are cancelled.

(4) Installing two air-conditioners in the same room

Diagram Description: Diagrams illustrating the procedure for setting remote control and indoor unit.

Similar procedure to other series: disconnect switching line on remote, use ACL switch, power cycle indoor unit.

(5) Selection of the annual cooling function

Diagram Description: Diagram showing jumper wire JA3 and interface kit SW2-4.

Enabled by default. Disabled by cutting JA3 or changing SW2-4. Control based on outdoor air temperature (below 5°C triggers 8th step fan speed, above 7°C returns to normal).

(6) High power operation

Initiates powerful cooling/heating for 15 minutes. Displays HIGH POWER mark. Not controlled by room temperature. Not available during dehumidifying and timer operations. Cancels under specific conditions. Not operable when unit is OFF.

(7) Economy operation

Initiates soft operation. Operates 1.5°C higher (cooling) or 2.5°C lower (heating) than set temperature. Displays ECONO mark. Cancels under specific conditions. Not operable when unit is OFF.

(8) Air flow direction adjustment

Adjustable via AIR FLOW buttons. Flap angles range from approx. 5° to 70°. Louver control includes swing, spot, wide modes. Memory flap function available.

Diagram Description: Diagrams showing flap and louver positions, angles, and swing motions for SRK-ZR series.

(9) 3D auto operation

Automatic adjustment of fan speed, flap, and louver based on temperature differences and operation modes (Cooling, Heating, Dehumidifying). Specific logic detailed.

Diagram Description: Diagrams illustrating the 3D Auto operation logic for SRK-ZR series.

(10) Timer operation

Includes Comfort start-up (ON timer), Sleep timer, OFF timer, and Weekly timer. Timer combinations and priority rules are described.

Diagram Description: Table showing timer operation combinations.

(11) Silent operation

Reduces outdoor fan and compressor speeds. Tables show specific speeds for SCM71, 80, 100 models.

(12) Night setback operation

Heating operation starts with setting temperature at 10°C upon receiving the "Night setback" signal.

(13) Air flow range setting

Diagram Description: Diagrams showing how to set air flow range for different installation locations.

Instructions to adjust left/right air flow range using specific button combinations.

(14) Wireless LAN connection function

Describes conditions for wireless LAN connection setting, operation details, and reset conditions.

(15) Outline of dehumidifying (DRY) operation

Diagram Description: Diagram showing fan speed and compressor areas for DRY operation.

Purpose is dehumidification. Controls fan speed and compressor based on temperature difference. Prevents over-cooling. May heat first if temperatures are low.

(16) Outline of automatic operation

Diagram Description: Diagrams showing automatic operation mode determination based on temperatures.

Mode determined by indoor/outdoor air temperatures. Mode changes under specific conditions. Setting temperature range is specified. Cooling operation controlled by display temps, heating temp compensated by +2°C with wired remote.

(17) Protective control function

(a) Dew prevention control: Prevents dewing. Operates if humidity is 68% or higher for 30 mins. Controls air capacity and wind direction. Resets when humidity drops or compressor is OFF.

(b) Frost prevention control: Prevents frosting. Details conditions, operation (compressor speed reduction, fan/valve control), and reset based on indoor heat exchanger temperature.

Diagram Description: Diagrams for frost prevention control.

(c) Cooling overload protective control: Prevents high pressure. Operates based on outdoor air temperature. Adjusts compressor speed limits.

Diagram Description: Diagrams for cooling overload protection.

1.1.4 SKM-ZSP series

(1) Operation control function by wireless remote control

• Remote control:
• Operation section: OPERATION MODE select, HI POWER/ECONO, ON TIMER, SLEEP, CLEAN switch, CANCEL buttons.
• Transmission section: ON/OFF, FAN SPEED, AIR FLOW (UP/DOWN), TEMPERATURE, OFF TIMER, ACL buttons.
• Unit display section: Unit ON/OFF button, Wireless remote control signal receiver, RUN light (green), TIMER light (yellow).

Diagram Description: Illustration showing the remote control layout for SKM-ZSP series.

(2) Unit ON/OFF button

Can be used when remote control batteries are weak or lost. Pushing once starts automatic mode; pushing again stops the unit. Unit automatically determines COOL, DRY, or HEAT mode based on room temperature.

(3) Auto restart function

Diagram Description: Diagram showing jumper wire J1.

Records operational status before power cut and resumes automatically. Timer settings and HIGH POWER operation are cancelled. Auto restart is set ON by default; can be disabled by cutting J1.

(4) Installing two air-conditioners in the same room

Diagram Description: Diagrams showing jumper wire J2 and remote control modification.

Procedure to prevent interference: disconnect jumper wire J2 on indoor unit PCB, and disconnect a switching line on the remote control battery area.

(5) High power operation

Initiates powerful cooling/heating for 15 minutes. Displays HIGH POWER mark. Not controlled by room temperature. Not available during DRY and timer operations. Cancels under specific conditions. Not operable when unit is OFF.

(6) Economy operation

Initiates soft operation. Operates 1.5°C higher (cooling) or 2.5°C lower (heating) than set temperature. Displays ECONO mark. Cancels under specific conditions. Not operable when unit is OFF.

(7) Air flow direction adjustment

Adjustable via AIR FLOW (UP/DOWN) button. Flap angles range from approx. 15° to 65° depending on mode. Swing and memory flap functions available.

Diagram Description: Diagrams showing flap positions, angles, and swing motions for SKM-ZSP series.

(8) Timer operation

Includes Comfort start-up (ON timer), Sleep timer, and OFF timer. Details are similar to other series.

(9) Outline of heating operation

Describes operation of major components (Compressor, Indoor fan, Outdoor fan, 4-way valve) in heating mode, including Thermostat ON/OFF, Defrost, and Failure states. Details fuzzy operation and hot keep operation.

(10) Outline of cooling operation

Describes operation of major components in cooling mode. Details fuzzy operation for air flow and compressor speed control.

(11) Outline of dehumidifying (DRY) operation

Diagram Description: Diagram showing fan speed and compressor areas for DRY operation.

Purpose is dehumidification. Controls fan speed and compressor based on temperature difference. Prevents over-cooling. May heat first if temperatures are low.

(12) Outline of automatic operation

Diagram Description: Diagrams showing automatic operation mode determination based on temperatures.

Mode determined by indoor/outdoor air temperatures. Mode changes under specific conditions. Setting temperature range is specified. Cooling operation controlled by display temps, heating temp compensated by +2°C with wired remote.

(13) Protective control function

(a) Frost prevention control: Prevents frosting. Details conditions, operation, and reset based on indoor heat exchanger temperature.

Diagram Description: Diagrams for frost prevention control.

(b) Cooling overload protective control: Prevents high pressure. Operates based on outdoor air temperature. Adjusts compressor speed limits.

Diagram Description: Diagrams for cooling overload protection.

1.1.5 SRF and SRR series

(1) Operation control function by wireless remote control

SRF series

• Operation section: OPERATION MODE, TEMPERATURE, HI/ECO (invalid), SILENT, ON TIMER, OFF TIMER, WEEKLY, CLEAN, SLEEP buttons.
• Transmission section: ON/OFF, FAN SPEED, AIR FLOW (UP/DOWN), NIGHT SETBACK, SET/Child Lock, CANCEL, TIMER, PROGRAM buttons.
• Unit display section: RUN (HOT KEEP) light, TIMER light, HI POWER light, AIR OUTLET SELECTION light, ECONO light.

Diagram Description: Illustration showing the remote control layout for SRF series.

SRR series

• Operation section: (Similar to SRF series)
• Transmission section:
• Unit display section: RUN (HOT KEEP) light, TIMER light, HI POWER light, ECONO light.

Diagram Description: Illustration showing the remote control layout for SRR series.

(2) Unit ON/OFF button

Can be used when remote control is unavailable. Operates in COOL, DRY, or HEAT modes. Unit automatically determines mode based on indoor temperature.

(3) Auto restart function

Diagram Description: Diagram showing jumper wire J170.

Records status before power cut and resumes automatically. Timer settings and HIGH POWER operations are cancelled. Set ON by default; can be disabled by cutting J170.

(4) Installing two air-conditioners in the same room

Diagram Description: Diagrams illustrating setting remote control and indoor unit.

Procedure to prevent interference: disconnect switching line on remote, power cycle indoor unit, use ACL switch.

(5) Selection of the annual cooling function

Diagram Description: Diagram showing jumper wire J172 and interface kit SW2-4.

Enabled/disabled via J172 or SW2-4. Control logic based on outdoor air temperature (below 5°C triggers 8th step fan speed; above A°C returns to normal, where A is 17 for SRR series, 7 for SRF series).

(6) High power operation

Initiates powerful cooling/heating for 15 minutes. Displays HIGH POWER mark. Not controlled by room temperature. Not available during dehumidifying and timer operations. Cancels under specific conditions. Not operable when unit is OFF.

(7) Economy operation

Initiates soft operation. Operates 1.5°C higher (cooling) or 2.5°C lower (heating) than set temperature. Displays ECONO mark. Cancels under specific conditions. Not operable when unit is OFF.

(8) Flap and louver control (SRF series only)

Adjustable via AIR FLOW (UP/DOWN) button. Flap angles range from approx. 5° to 60°. Swing and memory flap functions available.

Diagram Description: Diagrams showing flap positions, angles, and swing motions for SRF series.

(9) Air outlet selection (SRF series only)

AIR SELECTION button switches between upper/lower outlets and upper outlet only. Auto air outlet selection logic described for COOL/DRY and HEAT operations.

Diagram Description: Diagrams showing upper/lower air outlet selection and indicator lights.

(10) Timer operation

Includes Comfort start-up (ON timer), Sleep timer, OFF timer, and Weekly timer. Timer combinations and priority rules are described.

Diagram Description: Table showing timer operation combinations.

(11) Night setback

Heating operation starts with setting temperature at 10°C upon receiving the "Night setback" signal.

(12) Determining the operating mode

Cooling/heating modes are based on previous wireless remote control settings. If a different mode is selected, only the fan operates. Describes operation patterns and notes for different units (A unit, B unit).

(13) Drain pump abnormalities detection (SRR series only)

Describes drain pump motor operation during cooling/dehumidifying modes and after operation stops. Control A and Control B logic based on float switch detection are detailed. Anomalous stop indicated by E9 error.

(14) Outline of dehumidifying (DRY) operation

Diagram Description: Diagram showing fan speed and compressor areas for DRY operation.

Purpose is dehumidification. Controls fan speed and compressor based on temperature difference. Prevents over-cooling. May heat first if temperatures are low.

(15) Outline of automatic operation

Diagram Description: Diagrams showing automatic operation mode determination based on temperatures.

Mode determined by indoor/outdoor air temperatures. Mode changes under specific conditions. Setting temperature range is specified. Cooling operation controlled by display temps, heating temp compensated by +2°C with wired remote.

(16) Operation permission/prohibition control

Controlled by jumper wire (J3) and external signal into CnT. Normal operation enabled by shorting J3. Permission/Prohibition mode enabled by releasing J3. External input (CnT) controls operation start/stop. Priority order for CnT and CnTA inputs is described.

(17) External control (remote display) /control of input signal

(a) External control (remote display) output: Connectors (CnT) provide outputs for operation status (Operation, Heating, Compressor ON, Malfunction, Cooling, Fan, Defrost/oil return, Ventilation, Free cooling, IU overload alarm, Heater).

(b) Control of input signal: Connectors (CnT) for switch input, timer input. Level input and Pulse input methods are described. Remote operation input for multiple units (Max. 16) is detailed.

Diagram Description: Diagrams showing input/output connectors and signal priority.

(18) Hot keep operation

Indoor fan speed controlled based on indoor heat exchanger temperature to prevent blowing cool wind during heating. Control may not execute if fan speed is HI and room temp is 19°C or higher.

(19) Frost prevention control

Details operating conditions, anti-frost operation (compressor speed reduction, fan/valve control), and reset based on indoor heat exchanger temperature.

(20) Heating high pressure control

Start condition based on indoor heat exchanger temperature. Controls compressor stop and release temperature. Release condition based on indoor heat exchanger temperature.

(21) Current overload protective control

Details operating conditions and operation based on outdoor air temperature (Tho-A) and fan speed limits for SRF/SRR series.

(22) Indoor fan motor protection

Detects fan motor speed. Stops with anomalous stop (E16 or E20) if speed is too low or fails to reach required speed.

1.2.1 Remote control (Option parts)

(1) Wired remote control

Model RC-EX3D: Features touch panel LCD, Run/Stop switch, F1/F2 switches, operation lamp, USB port. Backlight and operation lamp luminance are adjustable. USB port for PC connection.

Diagram Description: Illustration of the RC-EX3D wired remote control with its components labeled.

Model RC-E5: Features a cover, various display areas (Operation mode, Set Temp, Timer, etc.), and buttons (Operation/stop, MODE, FAN SPEED, LOUVER, etc.).

Diagram Description: Illustration of the RC-E5 wired remote control with its components labeled.

(2) Operation control function by the wired remote control

Model RC-EX3D:

• Switching sequence of operation modes: Tap mode button on TOP screen, select desired mode. Not all modes may be displayed depending on unit combinations. Auto mode switches between cooling/heating automatically.
• CPU reset: Reset CPU via Menu > Service setting > Service & Maintenance > Service password.
• Power failure compensation function: Auto-restart function can be enabled/disabled via remote control settings. Memorizes operating status, mode, fan speed, temperature setting, etc. Timer settings (weekly, peak cut, silent) behavior during power failure is detailed.
• Alert displays:
• Communication check: Appears if communication between remote and indoor unit fails.
• Clock setting check: Appears if timer settings are made without clock setting.
• Misconnection: Appears if something other than an air-conditioner is connected.

Model RC-E5:

• Switching sequence of operation modes: DRY, COOL, FAN, HEAT, AUTO icons displayed.
• CPU reset: Performed by pressing CHECK and ESP buttons simultaneously.
• Power failure compensation function: Effective if selected in remote control settings. Memorizes conditions. Weekly timer setting is restored with holiday setting for all weekdays.
• [Parts layout on remote control PCB]: Diagram showing PCB components.
• Main/Sub setting: For multiple remote controls (max 2 per unit/group). SW1 on PCB sets Main/Sub. Specific displays/settings only available on the main remote control.

(3) Operation control function by the indoor control

(1) Auto operation:

Heating and cooling automatically switched based on temperature differences. Facilitates operation in intermediate seasons and unmanned operation. Logic based on indoor/outdoor temperatures and setting temperature. Cooling/heating switching can be adjusted via RC-EX3D. Thermostat control during auto cooling/heating is based on room temperature setting. If indoor heat exchanger temp rises high during heating, it may switch to cooling.

Diagram Description: Diagrams illustrating auto operation temperature zones and mode determination logic based on indoor/outdoor temperatures.

(2) Operations of functional items during cooling/heating:

Table detailing component operation (Compressor, Fan, 4-way valve, Drain pump) status (ON/OFF) for Cooling/Heating modes, Thermostat ON/OFF, Hot Start, Dehumidifying, etc.

Notes: (1) Operation/Stop controlled by remote/thermostat. (2) ON during drain pump motor delay control. (3) Drain pump ON setting selectable via indoor unit function setting.

(3) Dehumidifying (DRY) operation:

(a) FDTC series: Controls indoor temperature and humidity using relative humidity sensor (HS) and suction temperature sensor. Adjusts indoor fan tap based on temperature difference and humidity. Retains fan tap when humidity lowers or thermostat is OFF.

(b) FDE, FDUM series: Controls indoor temperature using return air temperature sensor. Adjusts indoor fan tap based on temperature difference. Retains fan tap when thermostat is OFF.

(4) Timer operation:

(a) RC-EX3D: Sleep timer (30-240 min), OFF timer (1-12 hrs), ON timer (1-12 hrs), ON/OFF timer by clock (5-min units, requires clock setting), Weekly timer (8 patterns/day). Combination table provided.

(b) RC-E5: Sleep timer (10 steps, OFF 1-10 hrs later), OFF timer (10-min units), ON timer (10-min units), Weekly timer (4 times/day). Combination table provided.

Diagram Description: Tables showing timer operation combinations for RC-EX3D and RC-E5.

(5) Hot start (Cold draft prevention at heating):

Performed during heating startup, mode change to heating, thermostat ON after OFF, or after defrost. Controls indoor fan motor speed to prevent cold drafts. Louver stays horizontal. Fan motor turns ON after 7 mins of continuous OFF during defrost.

(6) Hot keep:

Control performed at defrost start. Indoor fan speed follows thermostat OFF setting. Louver stays horizontal.

(7) Auto swing control (FDTC and FDE only):

(a) RC-EX3D: Louver control via "Direction" button. "Auto swing" for continuous movement, buttons [1]-[4] to fix position. Louver swings once on power on to detect position. Automatic louver level setting during heating (hot start, thermostat OFF). Louver free stop control available via service menu.

(b) RC-E5: Louver control via "LOUVER" button. "SWING" displayed for continuous movement. Pressing "LOUVER" while swinging stops at one of four positions. Louver swings once on power on. Automatic louver level setting during heating. Louver-free stop control via indoor function setting.

Diagram Description: Diagrams showing louver swing and stop positions.

(8) Thermostat operation:

(a) Cooling: Thermostat ON/OFF based on room temperature relative to setting temperature (-1°C to +1°C range). Thermostat ON if room temp is within -1 to +1°C of setting temp at cooling start.

(b) Heating: Thermostat ON/OFF based on room temperature relative to setting temperature. Thermostat ON if room temp is within -1 to +1°C of setting temp at heating start.

(c) Fan control during heating thermostat OFF: Selectable options: Low fan speed, Set fan speed, Intermittence, Fan OFF. Details "Intermittence" logic (5 min OFF, 2 min ULo fan, then back to state 1). Fan OFF if defrost signal received.

(d) Fan control during cooling thermostat OFF: Selectable options: Low fan speed, Set fan speed, Intermittence, Fan OFF. Details "Intermittence" logic (5 min OFF, 2 min ULo fan, then back to state 1).

(9) Filter sign:

Displayed on remote control after operation time accumulates to 180 hours (default). Can be set to 600 or 1000 hours. Unit stops after 24 hours further operation.

(10) Compressor inching prevention control:

(a) 3-minute timer: Inhibits compressor restart for 3 minutes after stop (thermostat, remote, anomaly). Invalidated at power on.

(b) 3-minute forced operation timer: Compressor will not stop for 3 minutes after ON. Stops immediately if unit stopped by ON/OFF or mode change. Louver returns to level position during heating forced operation thermostat OFF.

(11) Drain pump control:

Operates when inverter frequency is not 0 Hz during cooling/auto cooling/dehumidifying. Continues for 5 minutes after ON, even after stopping. Operates with 5-minute delay when compressor changes from ON to OFF. Also controlled by drain detection in other modes.

(12) Drain pump motor (DM) control:

Drain detection switch controlled by float switch and timer. Control A and Control B logic described for different operating conditions. Anomalous draining indicated by E9 error.

(13) Operation check/drain pump test run operation mode:

Entered via DIP switch (SW7-1) on PCB. Operation check mode allows operation by remote control without outdoor unit communication. Drain pump test run mode operates only the drain pump; protective functions are ineffective.

(14) Cooling, dehumidifying frost protection:

Prevents frosting. Compressor OFF if indoor heat exchanger temp drops to 1.0°C or lower. Resets if temp reaches 10°C or higher. Indoor fan speed increases if frost prevention control is active.

Diagram Description: Diagrams showing frost prevention temperature settings and fan speed increase logic.

(15) Heating overload protection:

Compressor stops if indoor heat exchanger temp is 63°C or higher for 2 seconds. Stops with anomalous stop (E8) if repeated. Indoor fan speed may increase if heating overload protection is active.

(16) Anomalous fan motor:

Stops with anomalous stop (E16 or E20) if fan motor speed is too low or fails to reach required speed.

(17) Plural unit control – Control of 16 units group by one remote control:

One remote control can manage up to 16 indoor units. Thermostat and protective functions operate independently per unit. Unit No. set by SW2 on PCB. Display on remote control shows smallest unit No. among operating units. Anomaly on one unit stops only that unit. Wiring procedure described.

Diagram Description: Diagrams showing unit wiring for group control.

(18) Fan speed setting control:

Air flow rate can be increased by changing fan tap via indoor unit function "FAN SPEED SET" on wired remote control. Standard, Setting1, Setting2, High speed taps available. Notes on factory default, hot-start conditions, and limitations with wireless remotes.

(19) Abnormal temperature sensor (return air/indoor heat exchanger) broken wire/short-circuit detection:

(a) Broken wire detection: Compressor stops if sensor detects -55°C or lower for 5 seconds. Restarts after 3 min delay, but stops again if detected continuously. Errors E7 (return air) or E6 (heat exchanger).

(b) Short-circuit detection: Compressor stops (E6) if heat exchanger sensor detects short-circuit for 5 seconds shortly after compressor ON during cooling.

(20) External input/output control (CnT or CnTA):

Connectors on indoor unit PCB for external control. RC-EX3D allows changing input/output functions. Remote operation with CnT/CnTA only is not possible. Priority order for combinations of CnT and CnTA input is described. Output signals for operation status monitoring (Operation, Heating, Compressor ON, Inspection/Error, Cooling, Fan, Defrost/oil return, Ventilation, Free cooling, IU overload alarm, Heater). Input signals for Run/Stop, Permission/Prohibition, Cooling/Heating, Emergency stop, Setting temperature shift, Forced thermo-OFF, Temporary stop, Silent mode. Level input and Pulse input settings described.

Diagram Description: Diagrams showing input/output connectors, signal priority, and connection examples.

(21) Operation permission/prohibition:

Effective when "Operation permission/prohibition" is set to "Valid". Controlled via CnT-6 or CnTA. Normal operation (factory default) vs. Permission/Prohibition mode. "Valid" mode allows operation via wired remote control (Level input) or starts operation (Pulse input). Card key switches or timers can control permission/prohibition.

Diagram Description: Diagrams showing operation permission/prohibition logic.

(22) Temporary stop input:

Unit stops operation when CnT-5 or CnTA input is OFF (Operation stop level). If CnT-5 is ON and CnTA is OFF, it stops operation. If CnT-5 is OFF and CnTA is ON, it stops operation.

(23) Selection of cooling/heating external input function:

(a) Level input: Input signal to CnT-4 or CnTA OFF-ON = Unit ON; ON-OFF = Unit OFF. Operation is not inverted. Latest operation has priority.

(b) Pulse input: Effective only when signal changes OFF-ON. Unit operation [ON/OFF] is inverted.

(c) Remote operation input: For multiple units (Max. 16). "Individual" (factory default) vs. "For all units" setting. External input to CnT-6 or CnTA on one unit can control all units in the system when "For all units" is selected.

Diagram Description: Diagrams showing external input/output connections for multiple units.

(24) Fan control at heating startup:

Fan speed is controlled during heating startup to prevent cold drafts. Fan speed is adjusted based on heat exchanger temperature and thermostat status.

(25) Room temperature detection temperature compensation during heating:

Room temperature detection is compensated during heating operation.

(26) Return air temperature compensation:

Return air temperature is compensated.

(27) High power operation (RC-EX3D only):

Initiates powerful cooling/heating for 15 minutes. Displays HIGH POWER mark.

(28) Energy-saving operation (RC-EX3D only):

Initiates soft operation to avoid excessive cooling/heating. Displays ECONO mark.

(29) Warm-up control (RC-EX3D only):

Control performed during heating startup to prevent cold drafts.

(30) Home leave mode (RC-EX3D only):

Sets a specific temperature for when the room is unoccupied.

(31) Auto temperature setting (RC-EX3D only):

Automatically sets temperature based on conditions.

(32) Fan circulator operation (RC-EX3D only):

Operates the fan for air circulation.

(33) The operation judgment is executed every 5 minutes (RC-EX3D only):

Operation mode is re-evaluated every 5 minutes.

(34) Auto fan speed control (RC-EX3D only):

Fan speed is automatically adjusted.

(35) Indoor unit overload alarm (RC-EX3D only):

Alarm triggered if the indoor unit is overloaded.

(36) Peak-cut timer (RC-EX3D only):

Timer to manage peak electricity usage.

(37) Motion sensor control (RC-EX3D and RCN-E2 only):

Uses motion sensor to detect presence and adjust operation.

1.3.1 Outline of heating operation

(1) Summary: Describes heating operation.

(2) Operation of major functional components in heating mode: Details component status (Compressor, Indoor fan, Outdoor fan, 4-way valve) during heating thermostat ON/OFF, Defrost, and Failure states.

(3) Defrost operation: Details conditions, operation, and reset for defrost cycle.

Diagram Description: Diagram illustrating defrost operation logic.

1.3.2 Outline of cooling operation

(1) Summary: Describes cooling operation.

(2) Operation of major functional components in cooling mode: Details component status during cooling thermostat ON/OFF, Failure states.

1.3.3 Protective control function

(1) Cooling overload protective control: Prevents anomalous high pressure during cooling. Operates when outdoor air temperature (TH2) is 38°C or more (or 41°C/47°C for specific models) for 30 seconds with compressor running. Adjusts compressor speed limits. Resets at 37°C (or 40°C for specific models).

Diagram Description: Diagrams showing compressor speed adjustment based on outdoor air temperature.

(2) Cooling high pressure control: Prevents anomalous high pressure operation during cooling. Detects outdoor heat exchanger sensor (TH1). Details compressor speed reduction based on outdoor heat exchanger temperature and outdoor air temperature.

Diagram Description: Diagrams showing compressor speed reduction based on outdoor heat exchanger temperature and outdoor air temperature.

(3) Cooling low outdoor temperature protective control: Prevents operation issues at low outdoor temperatures.

(4) Heating high pressure control: Prevents high pressure during heating.

(5) Heating overload protective control: Prevents overload during heating.

(6) Heating low outdoor temperature protective control: Prevents operation issues at low outdoor temperatures.

(7) Refrigeration cycle system protective control: Protects the refrigeration cycle.

(8) Service valve (gas side) closing operation: Describes closing operation of the gas side service valve.

(9) High pressure protective control (SCM100ZS-W only): Specific high pressure protection for SCM100ZS-W model.

(10) Compressor overheat protection: Protects compressor from overheating.

(11) Current safe: Protection against excessive current.

(12) Current cut: Cuts current under specific conditions.

(13) Outdoor unit failure: General protection against outdoor unit failures.

(14) Discharge pipe temperature sensor disconnection protective control: Protects against discharge pipe temperature sensor issues.

(15) Regulation of outdoor air flow: Controls outdoor air flow.

(16) Serial signal transmission error protection: Protects against serial signal transmission errors.

(17) Rotor lock: Detects and protects against rotor lock.

(18) Outdoor fan motor protection: Protects the outdoor fan motor.

(19) Outdoor fan control at low outdoor temperature: Adjusts outdoor fan operation at low temperatures.

(20) Outdoor fan control at overload: Adjusts outdoor fan operation during overload.

(21) Limit of the number of compressor starts: Limits the number of compressor starts to prevent damage.