HITACHI INVERTER-DRIVEN MULTI-SPLIT SYSTEM AIR CONDITIONERS

Important Notice

This air conditioner is for general use. Do not use for food, animals, plants, precision machinery, or art preservation.

Do not install in the following places:

• Areas with gas and oil droplets (causes fires, deformation, corrosion, damage). This includes places with oil, oil gas, sulfur gas, and hot springs.
• Areas that cause corrosion: Near the sea (salty environment), or in acidic/alkaline environments.

Electromagnetic Wave Considerations:

• When installing near medical equipment emitting electromagnetic waves, note that it may cause malfunction.
• Do not install the outdoor unit where electromagnetic waves are directly radiated to the electrical box.
• Install indoor units, outdoor units, controllers, and cables at least 3 meters away from strong electromagnetic wave sources like medical equipment.

Other Installation Precautions:

• Avoid installing where animals or plants will be directly affected by the wind, as it may have adverse effects.
• If using a wireless remote controller, keep it away from lighting equipment that might interfere with signal reception (more than 1m away).

Safety Summary

This section provides a "Safety Summary". Please read it carefully for correct installation.

Pay close attention to "Danger" and "Caution" markings. Installation errors can lead to significant harm.

After installation is complete, perform a test run to confirm there are no abnormalities. Follow the manual's instructions for methods and maintenance, and ensure customers keep the installation and operation manuals.

Definition for signal words

• DANGER: Immediate hazards which will result in severe personal injury or death.
• ➡️ (Enforcement matters): Machine with a ground terminal, the user must follow instructions for ground work.
• ❗ (Prohibitions): Indicates general behavior (non-specific object).

About Electrical Works

⚠️ When performing electrical work, ensure it is done by qualified personnel. Do not attempt to complete complex electrical work yourself to avoid electric shock.

Perform electrical work according to the Installation Manual and all relevant regulations and standards. Failure to do so may result in electric shock or fire due to insufficient capacity or inadequate performance.

• Use the specified wire for connections between products. Incorrect wire selection can cause fire or electric shock.
• Ensure wiring terminals are tightened securely with specified torques. Loose connections can lead to fire or electric shock.
• Fix cables securely; external forces on terminals can cause fire.
• Use an ELB (Earth Leakage Breaker). Failure to do so poses a risk of electric shock or fire.
• Before electrical wiring, inspection, or opening service covers, completely turn off the power to avoid electric shock.
• Check that the ground wire is securely connected. Improper grounding can lead to electrical shock. Do not connect the ground wire to gas piping, water piping, lighting conductors, or telephone ground wiring.

About Installation

⚠️ When installing, follow the installation manual precisely. Failure to do so may result in water leakage, electric shock, or fire.

Install the unit where it can withstand its weight. Incomplete installation can cause the unit to fall and result in injury.

Do not install near flammable gases or in locations where flammable gases are suspected, as this may cause fires or other accidents.

Do not climb on the air conditioner or place objects on top of it to avoid falling damage.

In case of refrigerant leakage, immediately turn off any fire sources (e.g., stoves), remove refrigerant from the ground, ventilate the area by opening doors and windows, and contact your service contractor.

Do not connect the indoor unit drain pipe directly to drainage ditches. Biogas can be produced and enter the indoor space, leading to poisoning.

Caution

• Use adequate non-flammable refrigerant (R410A) for the outdoor unit. Do not charge with Oxygen, acetylene, or other flammable/poisonous gases, as they are extremely dangerous and can cause explosions and fires.
• Ensure the condensation water drain pipe can drain properly. Incorrect piping may cause water to enter the house or wet furniture.
• Tighten the flare nut to the specified torque. Overtightening can crack the flare nut and cause refrigerant leakage.
• During field decoration construction, do not operate the unit and prepare it to prevent dust and defacement.
• Before unit operation, ensure the field is clean, free of airborne objects, and has no unusual smells. This prevents future issues like poor cooling or water leakage.

1. Common Items

1.1 Combination of Indoor Unit and Outdoor Unit

Refer to the table for selecting the outdoor unit and the number/capacity of indoor units.

For systems where all indoor units operate simultaneously, the total indoor unit capacity should be less than or equal to the outdoor unit capacity.

For systems where indoor units do not operate simultaneously, the total indoor unit capacity can be up to the maximum against the outdoor unit capacity.

1.2 Operation Temperature Range

DB: Dry Bulb, WB: Wet Bulb

1.3 Cooling Operating Instructions

The cooling operation shall be performed using the same refrigerant system for the indoor unit.

1.4 Note

This system has a 4-hour protection feature; stop reason code "d1-22" will be displayed. To operate within 4 hours, follow these steps:

1. Power ON the indoor and outdoor units.
2. Wait 30 seconds.
3. Press the outdoor unit's PSW1 button for more than 3 seconds.

2. Transportation and Handling

2.1 Transporting the Outdoor Unit

Observe the following items when transporting the outdoor unit. Keep the packaging intact as much as possible until it reaches the installation location.

Hanging Method Under Packing Condition:

Hang the unit using two ropes. Ensure the rope length is between 0.7m and 1.0m. Do not remove the top packing material and tape during hanging. Push wire rope through the hang hole and secure with a shackle.

2.2 Accessory Parts

Confirm the following accessory parts for the outdoor unit before installation.

3. Before Installation

3.1 R410A Refrigerant Considerations

R410A refrigerant operates at approximately 1.4 times the pressure of R22 and is more susceptible to moisture, acid materials, oil, and other impurities. The refrigerant oil also differs. During installation, be careful to avoid water, impurities, and mixing with existing refrigerants or oils.

The product's design pressure is 4.15 MPaG.

3.2 Special R410A Tools Required

To prevent accidental mixing of different refrigerants or oils, charging connection sizes have changed. Special R410A tools are necessary. Tools that contact refrigerant must be specifically for the new refrigerant.

Symbol Description:

• ●: for new and old type refrigerant
• ○: only for R410A (not for R22)
• ◍: only for R407C (not for R22)
• ☍: for two types R410A and R407C

3.3 Piping and Connection Parts

For R410A piping and connection parts, flare nut and pipe flare sizes have changed. Refer to the specifications below.

☍: Can not be processed (1/2H material)

☍ Please use the attached flare connecting pipe.

Pipe Thickness Selection

Due to design pressure changes, pipe thickness and material must also be changed.

Connection Selection

Due to design pressure changes, connection pipe (elbow, etc.) thickness also changes. When using 1/2H material, bending and flaring cannot be processed. Follow the rules below for minimum thickness selection. Note that flare nut sizes also change.

4. Installation Work

4.1 Outdoor Unit Installation Place Selection (Common Items)

Select the installation location carefully, considering the following points:

1. Ensure adequate space for normal operation and maintenance.
2. Install where ventilation is good and the area is dry.
3. Install in a shaded location, away from direct sunlight or high-temperature heat radiation.
4. Choose a spot where the unit's sound will not disturb neighbors.
5. The unit's air outlet should not blow directly towards plants or neighbors' windows.
6. Provide a foundation to support all feet of the outdoor unit.
7. Locate where the heat exchanger will not inhale dust or paper scraps.
8. Install as far as possible from areas with reverse wind (wind blowing directly against the fan). If installed on a roof or open space with strong winds blowing directly against the unit, ensure strong winds do not blow directly against the air outlet grille.
9. Do not install inside the house.
10. Do not place flammable objects near the unit to prevent fires.
11. Avoid installing where there is a high level of oil mist, salty air, or harmful gases like sulphur.
12. Do not install where electromagnetic waves are directly radiated to the electrical box.
13. Install the outdoor unit at least 3 meters away from electromagnetic wave radiators.

Strong Wind Blowing Directly Against the Product Installation Method

For installations on roofs or open spaces prone to strong winds, follow these instructions:

Please note that strong winds blowing directly against the air outlet grille can prevent necessary airflow and lead to unit failure.

Wind Break Cover Plate Type:

In open spaces, use steel wire cables or other means to secure the unit against strong winds.

4.2 Installation Space

Ensure adequate maintenance space around the outdoor unit as shown below.

1) Obstruction in the Air Inlet Side

(a) When the above is open

(b) When obstruction is at the top

2) Obstruction in the Air Outlet Side

(a) When the above is open

3) Obstruction at Both Sides

(a) When the above is open

(b) When obstruction is at the top

4) Multiple Rows Side by Side Installation (Roof, etc.)

4.3 Foundation Work

1) Anchor Bolts Installation

If the 170mm dimension is ensured and there is no interference with the foundation base, piping work can be directed downwards.

2) Vibration and Inclination Prevention

To prevent the unit from dumping, excessive noise, or tilting due to gusts and earthquakes, ensure the foundation work is robust. Use fixed brackets and consider installing anti-vibration rubber if necessary to isolate vibration transmission to buildings.

3) Confirm Drainage Smooth Flow

During defrost operation, condensation water is discharged. Select the best drainage area and ensure water flows to a drainage ditch. The drain hole position is shown with dimensions.

4) Shelf Installation

When using standard parts shelves that are narrower than the outdoor unit base bracket, follow the figure below. Use a wider flat base to support the full weight of the outdoor unit between the standard parts shelf and the outdoor unit base bracket feet.

5. Refrigerant Piping Work

5.1 Refrigerant Pipe

1) Refrigerant Pipe Selection

• Prepare refrigerant pipes as supplied by the field.
• Select clean copper pipes, ensuring no dust or moisture inside.
• Cut refrigerant piping using a pipe cutter. Blow out dust and foreign materials with nitrogen or dry air before connecting. Avoid using saws or grinding stones that produce powder.

Cautions for Refrigerant Piping Work (Example)

2) Piping Direction

The pipe can be connected in four directions.

(Unit: mm)

Pipe Combination (Accessory Parts):

3) Refrigerant Piping Fixation Methods

Connect the indoor and outdoor units with field-supplied refrigerant piping. Suspend the refrigerant piping at certain points to prevent it from touching weak parts of the building (e.g., walls, ceilings). Touching can cause abnormal sound due to vibration. Pay special attention for short piping lengths.

4) Refrigerant Piping Limitation and Multi-Kit Pipe

Longer pipes can reduce air conditioner cooling and heating capacity. This factor must be considered when selecting piping specifications.

※1: E-N55HT (Header Branch), it can be used that each indoor unit distribution and connection.

Multi-kit pipes must follow requirements; remove unused pipes. Welding other pipes into the multi-kit pipe is necessary to avoid reducing cooling capacity.

Line Branch Pipe

Header Branch Pipe

5) Setting of the Multi-Kit Pipe

For multi-kit pipes connected to indoor units, use optional multi-kit pipe set parts to prevent uneven refrigerant distribution and capacity reduction. Do not connect using standard connectors.

1) Line Branch (Use the line branch pipe), As shown below:

• Main pipe: The pipe between each multi-kit pipe or the pipe between outdoor units to the first multi-kit pipe.
• Main Branch: The multi-kit pipe has two multi-kit pipes which connect with more than one indoor unit.
• Setting Condition: Limited to third branch pipe, but only two main branches.

Setting Ways of Branch Pipe

The Line Branch Pipe Fixed Limits

Horizontal

• The branch pipe must be set in the same plane.
• Outdoor unit connection pipe shall ensure that the straight pipe is above 0.5m.

Vertical

It is divided into two kinds: upward and downward.

2) Header Branch (Use the header branch pipe), As shown below:

Note: The header branch pipe cannot be continuously installed.

The Header Branch Pipe Fixed Limits

The header branch pipe must be installed horizontally.

3) Mixing Setting of Line Branch and Header Branch, As shown below:

Note: 1. The line branch pipe cannot be connected after the header branch pipe. 2. The first branch pipe cannot use the header branch pipe.

5.2 Refrigerant Piping Work

1. Confirm that the stop valves of the outdoor unit are closed.
2. Connect the piping between the indoor and outdoor unit. When tightening piping joints, coat the inside and outside of the flare piping with refrigerant oil (field-supplied). Tighten using a double spanner according to the specified torque. After tightening, confirm gas leakage again. Blow nitrogen into the piping during brazing. Use the attached flange combination and washer.
3. Connect the indoor and outdoor units with field-supplied refrigerant piping. Suspend the piping at certain points to prevent it from touching weak building parts (wall, ceiling, etc.). Touching may cause abnormal sound due to vibration.
4. Perform the air-tight test. Connect a gauge manifold using charging hoses with a vacuum pump or nitrogen cylinder to the check joints of the liquid and gas line stop valves. Apply nitrogen gas pressure of 4.15MPaG. Do not open the stop valves.

Required Torque

(1) After connection piping and before the airtight test, remove the liquid and gas stop valve caps. Ensure the spindle valve is closed with the specified torque. Do not overtighten the flare nut, as it can cause spindle valve leakage.

Do Not Apply the Double Spanner Work Here. Refrigerant Leakage Shall Occur.

5.3 Vacuum

1. Refer to the nameplate inside the service cover for stop valve operation details.
2. Connect a manifold gauge to the check joints on both sides. Continue vacuum pumping until the pressure reaches -0.1MPa (-750mmHg) or lower for one to two hours.
3. After vacuum pumping, close the manifold valve, stop the vacuum pump, and leave it for one hour. Check that the pressure in the manifold gauge does not increase.
4. Use charging hoses (as check joints and flare nuts may not connect directly). After the work, tighten the flare nut with 16Nm of torque.
5. Check for gas leakage at flare nut connections or brazed parts using a gas leakage tester or foaming agent. Use the recommended foam testing fluid. Do not use general household cleaners.

Vacuum Drying Determination Example

Note: 1. A slight refrigerant leakage sound when removing the spindle valve cap of the stop valve is normal. 2. Use tools and measuring instruments specifically designed for new refrigerant (R410A). 3. If a vacuum degree of -0.1MPa (-750mmHg) is not achieved, leakage is considered to exist. Check for gas leakage again. If no leakage is found, operate the vacuum pump for one to two hours.

Implement vacuum drying determination to confirm the absence of water in the system. If moisture is present, extend vacuum time or install a drying filter. Failure to do so can lead to unit failure and difficulties in handling.

5.4 The Additional Refrigerant

The outdoor unit is pre-filled with refrigerant, but additional refrigerant may be needed based on pipe length. Calculate the filling amount using the following formula and table:

Calculation Formula:

W: Additional refrigerant of liquid pipe (kg) = W11 + W12 + W13

• W11: Φ12.7 liquid pipe length (m) × 0.12 (kg)=
• W12: Φ9.53 liquid pipe length (m) × 0.07 (kg)=
• W13: Φ6.35 liquid pipe length (m) × 0.03 (kg)=

W Total =

☍ Additional refrigerant W exceeds the amount of additional refrigerant filling upper limit, adjust the length of piping, such that W does not exceed the value of upper limit.

2. Fully open the gas line stop valve and slightly open the liquid line stop valve.
3. During cooling operation, connect the gauge manifold using charging hoses with a refrigerant charging cylinder to the check joint of the liquid line stop valve. (Refrigerant charging quantity tolerance is around ± 0.1kg.)
4. Fully open the liquid line stop valve after completing refrigerant charge.
5. Finally, lock the spindle valve cap of the liquid stop valve according to the following tightening torque.

The Cap Tightening Torque:

• Liquid: 20 Nm
• Gas: 49 Nm

6) Air-Tight Test

Be sure to perform the air-tight test. Additional refrigerant that is too much or too little can result in compressor failure or other abnormal conditions. Charge refrigerant according to calculated values.

Liquid piping must be thermally insulated to prevent poor performance and condensation on low-pressure pipe surfaces.

5.5 Caution of The Refrigerant Leakage

When installing air conditioners in rooms, refrigerant concentration must not exceed specified limits in case of leakage. R410A is non-flammable and non-toxic, but significant leakage filling a room can cause choking hazards. This is especially true for long-distance piping connections with large refrigerant amounts. Ensure indoor unit installation is in a room where refrigerant concentration can be kept below limits even in case of leakage.

Calculate limits refrigerant concentration by the following formula:

The total amount of refrigerant within the system (kg) / Installation the product of the room indoor volume (m³) ≤ limits refrigerant concentration

R410A (0.3kg / m³)

If the calculation result exceeds the limits, implement the following treatment methods:

1. Set up refrigerant leakage detector alarms linked to mechanical ventilation devices. (Ventilation capacity should be more than 0.4 m³/min per ton of cooling capacity).
2. Create effective ventilation mouths between adjacent rooms (e.g., openings without doors, or openings with more than 0.15% floor area on the upper and lower parts of the door) to keep leakage refrigerant concentration below the limit.

Example: Total amount of refrigerant within the system: 20kg

Note: 1) The amount of leakage refrigerant is 20kg for all room sizes. 2) The room must not exceed the limits refrigerant concentration of 0.42kg/m³.

New refrigerant R410A product notes: Since R410A is a non-azeotropic refrigerant, its composition changes upon leakage. It cannot be directly added; reprocessing is required.

5.6 Caution of Measure Pressure Data from The Check Joints

Measure pressure data from the check joints of the gas line stop valve (A) and the piping line (B). Adjust high and low pressure positions based on the operation state. Refer to the table for details.

5.7 Refrigerant Recovery Methods

When moving the unit, recover outdoor refrigerant following these steps:

1. Close the gas line stop valve, liquid line stop valve, and manifold gauge.
2. Turn on the power source.
3. Set outdoor unit electrical board DSW1-1 to ON. Implement cooling operation, then close the liquid line stop valve to start refrigerant recovery.
4. When the low-pressure (gas line stop valve) side reaches -0.01MPa (-100mmHg), take the following actions rapidly:
   1. Close the gas line stop valve.
   2. Set outdoor unit electrical board DSW1-1 to OFF (Unit stop).
5. Turn off the power source.

Please do not let the low-pressure gauge measure pressure lower than -0.01MPa. Low pressure below -0.01MPa during refrigerant recovery can result in compressor failure.

6. Electrical Wiring

CAUTION: All field wiring and electrical components must comply with local codes.

6.1 Wiring Capacity

1. The indoor and outdoor unit transmission cable is non-polar.
2. For the earth leakage breaker, select a "high-speed type" (active time less than 0.1 sec.).
3. Install over current breaker, manual switch, and earth leakage breaker (ELB) together.
4. Outdoor unit power supply specification: 3230V / 380V 60Hz.
5. Wiring capacity is detailed in the following table:

Note: When selecting the earth leakage breaker specification, refer to the table above. For 380V power supply, use 3Φ4 wire.

※ Piping thermal insulation material: Please use heat-resistant specification products that can withstand high-temperature gas piping.

6.2 Wiring Essential

Follow these essentials for power source cords and transmission cables:

1. To prevent electric shock, turn off power supply completely before opening service covers for electrical wiring, maintenance, or other operations.
2. Ensure indoor unit power supplies connect to the same outdoor unit. Install an inverter-corresponding type earth leakage breaker (ELB) and manual switch for each indoor unit.
3. The transmission cable connection must be with the same refrigerant cycle system. If connected to a different system, abnormal operation may occur.
4. Use 2-core shielded twist pair cable (0.75mm² or above) for transmission cables between indoor and outdoor units, and between indoor units (DC5V). Total length must be within 1000m.
5. Use 2-core wire for transmission cable connections. Do not use more than 3-core wire.
6. Check if the power supply voltage matches the rating voltage within ±10%. Higher or lower voltage can damage the unit.
7. Check electrical wire capacity. Insufficient power source capacity can prevent system startup due to voltage drop.
8. Ensure indoor and outdoor units are grounded to prevent electric shock and accidents. Use grounding resistance of 100Ω or less, performed by qualified personnel.
9. Turn off power supply completely before opening service covers for electrical wiring, maintenance, or other operations.

Caution of Indoor and Outdoor Unit Connection Wiring Construction:

Keep the transmission cable and 220V power source cord more than 5-6cm apart. Do not use coaxial cable. Incorrect connection of transmission cable and power source cord can burn the outdoor unit's PCB.

10) Indoor and Outdoor Unit's Power Source Cord and Connection Wiring Methods:

11) Wiring Connection Port:

After wiring, seal to prevent water invasion into the metal conduit pipe. Ensure terminal plugs are attached with insulation tape or sleeve.

7. Dip Switch (DSW) Setting of Outdoor Unit

TURN OFF all power sources before setting. Switches will not function, and settings will be invalid if power is on.

1) Transmission Method Setting

For multiple outdoor units sharing the same transmission line, set the refrigerant cycle number and end terminal resistance.

Setting of Refrigerant Cycle Number:

Setting of End Terminal Resistance (DSW5):

The unit is factory set with pin 1 of DSW5 at the "ON" side. If there are 2 or more outdoor units in the same H-link, set pin 1 of DSW5 to "OFF" for the 2nd unit onwards. If only one outdoor unit is used, no setting is required.

2) Lift Difference Setting

Set the lift difference between the outdoor and indoor units using DIP switch (DSW6) on the outdoor unit PCB.

3) Others Setting Switch

DSW1 Test Operation Setting:

Settings for Factory Setting, Cooling Operation, and Compressor Forced Stop.

DSW2 Auxiliary Function Setting:

Settings for High Efficiency Fan Motor, Function Setting, and External I/O Setting.

DSW3 Capacity Setting:

Each model is set based on the table.

8. Test Run

Before Test Run

Before starting the test run, re-confirm the installation for any problems and check the following:

• Confirm with the outdoor unit's installation manual.
• Refrigerant piping and transmission cable connection must be with the same refrigeration cycle. Incorrect connection can cause abnormal operation.
• Use a 500V electrical resistance tester to confirm electrical parts between terminals and earth have a resistance of 1MΩ or more. If less than 1MΩ, insulation is poor; do not operate the unit. (Do not input power source to terminals No.1,2 of transmission wiring.)
• If the power source wiring phase is incorrect, the unit will not operate, and the remote controller will display alarm code 05. Check the phase at the electrical box caution nameplate and replace if necessary. Perform this work with the power source turned off.
• Ensure the outdoor unit's oil heater has been powered for at least 12 hours before use.

Test Run

After installation is complete, perform the test run according to the following procedure. Confirm there is no abnormal operation before handing over the system to the customer.

1. Ensure the outdoor unit's gas stop valve and liquid stop valve are fully open.
2. Test each indoor unit in turn to confirm the refrigerant cycle system and electrical wiring system are the same. (If multiple indoor units operate simultaneously, consistency may be difficult to confirm.)
3. Follow the procedure below to test run and check for abnormalities:
4. 3.1 Depress the "MODE" and "CHECK" switches together for more than 3 seconds. The "TEST RUN" indicator and the connected unit count will appear on the remote control switch.
5. Cooling Operation Conditions: Room temperature DB 21°C, WB 15°C; Outside air temperature DB -5°C or more. (Air conditioner cannot operate below -5°C outside air temperature.)
6. If operating multiple indoor units with the remote controller, confirm the displayed unit count. If no indication appears or the count is smaller than actual, abnormalities exist. Press "MODE" again to set the desired operation mode.
7. 3.2 Depress the "RUN/STOP" switch. The "TEST RUN" operation will begin (with a 2-hour OFF-TIMER set). The test run will finish after 2 hours or when "RUN/STOP" is pressed again.
8. 3.3 To end the test run, wait 2 hours or press the "RUN/STOP" switch again.

Note: After the product stops operation, the compressor continues to run for a period (about 10 minutes) to recover piping refrigerant to the outdoor unit. This is not a product failure or abnormality. During test running, if a protection device activates due to an abnormality, the controller's operation indicator will blink, displaying "Alarm" (abnormality), and the setting temperature display will show the alarm code.

Refer to page 22 for alarm codes and treatment. If unable to resolve, contact your contractor.

Alarm Code

PS: Remote control operation indicator flashes once every 2 seconds. Symbol between indoor unit and remote control indicates transmission abnormality (connector loss, loose, incorrect wiring, disconnection).

4) Finally, deliver the guarantee, operation manual, and installation manual, etc. to the customer.

Danger: Before test running preparation, do not start running. Be sure to confirm electrical wiring, etc.

Test Run and Maintenance Record