11-1. Before a test run
After the wiring work has been completed, measure the insulation resistance, and make VXUHWKDWLWUHDGVDWOHDVW0ȍ
- Failure to do so may result in electric leakage, malfunction, or fire.
Turn on the power at least 12 hours before starting operation. Keep the power turned on throughout the operating season.
- Insufficient energizing will result in malfunction.
・Before performing a test run, turn off the power to the outdoor unit, and disconnect the power cable from the power supply terminal block to measure the insulation resistance.
・Measure the insulation resistance between the power supply terminal block and the earth with a 500 V ohmmeter, DQGPDNHVXUHLWLVDWOHDVW0ȍ
・,IWKHLQVXODWLRQUHVLVWDQFHLV0ȍRUDERYHFRQQHFWWKHSRZHUFDEOHWRWKHSRZHUVXSSO\WHUPLQDODQGWXUQRQWKH SRZHUDWOHDVWKRXUVEHIRUHVWDUWLQJRSHUDWLRQ,IWKHLQVXODWLRQUHVLVWDQFHLVEHORZ0ȍGRQRWRSHUDWHWKHXQLW and check the compressor for a earth fault.
・While the unit is turned on, the compressor will remain energized even when it is stopped.
immediately after installation or when the main power to the unit has been turned off for a long time because of the stagnation of refrigerant in the compressor.
・By turning on the main power and energizing the unit for 12 hours or longer, the refrigerant in the compressor will evaporate and the insulation resistance will rise.
・Do not apply an ohmmeter voltage to the terminal block for transmission cables. Doing so will damage the control board.
・Do not measure the insulation resistance of the transmission terminal block of the unit remote controller.
・Check for refrigerant leakage and for loose power cables and transmission cables.
・Check that the high-pressure side and low-pressure side service valves are fully open. Tighten the valve caps.
・Check the phase order of the power supply and the interphase voltage. If the voltage is out of the ±10% range, or if the voltage imbalance is more than 2%, discuss the countermeasure with the customer.
・When a transmission booster unit is connected, turn on the transmission booster unit before turning on the outdoor unit. If the outdoor unit is turned on first, the refrigerant circuit connection information will not be properly verified. If the outdoor unit is turned on first, turn on the transmission booster unit and then power reset the outdoor unit.
・When a power supply unit is connected to the centralized control transmission cable, or when power is supplied from a system controller with a power-supply function, perform a test run with the power supply unit being energized. Leave the power jumper connected to CN41.
・When power is turned on or after power recovery, performance may degrade for approximately 30 minutes.
11-2. Function setting
Make function settings by setting the dipswitches SW4, SW6, and SWP3 on the main board.
Write down the switch settings on the electrical wiring diagram label on the control box front panel for future reference when the control box needs to be replaced.
・Take the following steps to make temperature unit (ºC or ºF) settings.
① Set the 10th bit of SW6 to ON.
② Set SW4 as shown in the table below to select the setting item No.921. (The setting item No. will be displayed on LED1.)
③ Press SWP3 for two seconds or longer to change the settings. (The settings can be checked on LED3.)
Setting item No.
SW4 0: OFF, 1: ON *1 Setting (LED3 display) *2
1 2 3 4 5 6 7 8 9 10 Unlit Lit
unit setting 921 1 0 0 1 1 0 0 1 1 1 ºC ºF
*1 Make the SW4 setting after the unit is energized.
*2 This will blink while the system is starting up.
・Make various function settings by setting SW5 and SW6, referring to the table below.
Setting content Setting
Switch setting timing
SW5-1 Centralized control switch Without connection to the centralized controller
With connection to the
centralized controller Before being energized SW5-2 Deletion of connection information Normal control Deletion Before being energized
Preset before shipment
SW5-4 – –
SW5-5 – –
SW5-6 – –
SW5-7 – –
SW5-8 – –
Setting content Setting
Switch setting timing
SW6-1 – – – –
SW6-2 – – – –
SW6-3 – – – –
High static pressure setting Refer to *1. Refer to *1. Before being energized SW6-5
SW6-6 – – – –
SW6-7 Low-noise mode selection Performance priority Low-noise priority Any time after being energized SW6-8 Selection of Low-noise or Demand Low-noise (Night) Demand Before being energized SW6-9 Selection of Diagnostic display or
Function detail setting Refer to *2. Refer to *2. Any time after being energized SW6-10
* Do not change the factory settings of SW5-3 through SW5-8.
* Unless otherwise specified, leave the switch to OFF where indicated by "–," which may be set to OFF for a reason.
SW6-5: ON SW6-5: OFF
SW6-4: ON 80 Pa 60 Pa
SW6-4: OFF 30 Pa 0 Pa
SW6-10: ON SW6-10: OFF
SW6-9: ON LED (round type) No. 0 to 1023 LED (7seg) No. 1024 to 2047 SW6-9: OFF Function setting No. 0 to 1023 LED (7seg) No. 0 to 1023
11-3. Operation characteristics in relation to the refrigerant charge
It is important to have a clear understanding of the characteristics of refrigerant and the operation characteristics of air conditioners before attempting to adjust the refrigerant charge in a given system.
・During cooling operation, the amount of refrigerant in the accumulator is the smallest when all indoor units are in operation.
・During heating operation, the amount of refrigerant in the accumulator is the largest when all indoor units are in operation.
・Refrigerant undercharge creates a tendency for the discharge temperature to rise.
・Changing the amount of refrigerant in the system while there is refrigerant in the accumulator has little effect on the discharge temperature.
・The higher the high pressure level, the more likely it is for the discharge temperature to rise.
・The lower the low pressure level, the more likely it is for the discharge temperature to rise.
・When the amount of refrigerant in the system is adequate, the compressor shell temperature is 10 to 60ºC (50 to 140ºF) higher than the low-pressure saturation temperature. If the temperature difference between the compressor shell temperature and low-pressure saturation temperature is 5ºC (41ºF) or less, refrigerant overcharge is
11-4. Operation check
The following symptoms are normal and do not indicate a problem.
Events Display on
The auto vane automatically switches air flow direction.
Normal display The auto vane may switch over to horizontal air flow operation from vertical air flow operation in cooling mode if the vertical air flow operation has been running for one hour. At defrost in heating mode or immediately after heating start-up/shutdown, the auto vane automatically switches to horizontal air flow for a short time.
The fan speed automatically changes during heating operation.
Normal display The fan operates at Very Low speed when the thermostat is turned off, and automatically changes over to the preset speed according to the timer setting or refrigerant temperature when the thermostat is turned on.
The fan stops during heating operation. "Defrost" The fan remains stopped during the defrost cycle.
The fan keeps running after the unit has stopped.
No display After the unit has stopped during heating operation, the fan operates for one minute to exhaust heat.
At the beginning of heating operation, the fan cannot be manually set.
"Stand By" The fan operates at Very Low speed for five minutes after heating operation starts or until the refrigerant temperature reaches 35°C (95°F), then the fan operates at Low speed for two minutes, and finally the fan operates at the preset speed.
When the main power is turned on, the display as shown right appears on the remote controller for about five minutes.
The system is starting up. Wait until "HO" or "PLEASE WAIT" stops blinking and goes off then try again.
The drain pump keeps running after the unit has stopped.
No display The drain pump remains in operation for three minutes after the unit in cooling mode has stopped.
The drain pump goes into operation when drain water is detected, even when the unit is stopped.
The indoor unit emits noise when switching from heating to cooling and vice versa.
Normal display R2 system This is a normal sound of the refrigerant circuit operating properly.
Hybrid City Multi system
Some air may be left in the water circuit. Referring to the Service Handbook provided with the HBC controller, take the appropriate measures.
Immediately after startup, the indoor unit emits the sound of liquid flowing.
Normal display Unstable flow of the heating medium produces a sound. This is temporary and does not imply a problem.
In a short while after the outdoor unit stops, the unit makes a clicking sound.
No display After the unit stops and before the unit performs pressure equalization, the pressure difference temporarily becomes small and the check valve may vibrate and make a sound. This is temporary and does not imply a problem.
Drain water comes out of the outdoor unit from the bottom part of the heat
No display This ensures proper drainage of drain water in case the drain water freezes and remains in the outdoor unit during the heating operation at low ambient temperature.