HITACHI RAM-SJ24H3NV Split Unit Air Conditioner



Outdoor Unit

  • Carefully read through the procedures of proper installation before starting installation work.
  • The sales agent should inform customers regarding the correct operation of installation.

Tools Needed For Installation Work

  • (±) 8 Screwdriver
  • Measuring Tape
  • Knife
  • Saw
  • Pipe Cutter
  • Hexagonal Wrench Key ( IO 4mm)
  • Power Drill (065mm – 080mm) • Vacuum Pump
  • Pliers or Wrench
  • Torque Wrench
  • Vacuum Pump Adaptor
  • Flare Tool
  • Gas Leakage Detector • Manifold Valve
  • Charge Hose
  • Reamer
  • File


  • Read the safety precautions carefully before operating the unit.
  • The Read the contents safety of this precautions section are carefully vital to before ensure operating safety. the Please unit. pay special attention to the following sign. Lt,
       Incorrect methods of installation may cause death or serious injury.
    • CAUTION .
      Improper installation may result in serious consequence.
      Be operating sure that the the unit as unit described operates in in the proper user’s condition guide. after installation.
      Explain to customer the proper way of operating the unit as described in the user’s guide.


  • Flare nut must use a torque wrench without fail. Tighten with the specified tightening torque. If the flare nut is tightened too much, after a long period of time, the flare nut breaks, Gas leakage, stagnation, touching fire, rarely cause ignition.
  • Sharp bending of the pipe use the polyethylene rod, bend not crushed the pipe. Gas leakage from the crushed part, stagnation, touching fire, rarely cause ignition.
  • Please request your sales agent or qualified technician to install your unit. Water leakage, short circuit or fire may occur if you do the installation work yourself.
  • Please observe the instructions stated in the installation manual during the process of installation. Improper installation may cause water leakage, electric shock and fire.
  • A brazed, welded, or mechanical connection shall be made before opening the valves to permit refrigerant to flow between the refrigerating system parts. A vacuum valve shall be provided to evacuate the interconnecting pipe and/ or any uncharged refrigerating system part.
  • Mechanical connectors used indoors shall comply with ISO 14903. When mechanical connectors are reused indoors, sealing parts shall be renewed. When flared joints are reused indoors, the flare part shall be re-fabricated.
  • Refrigerant tubing shall be protected or enclosed to avoid damage.
  • Make sure that the units are mounted at locations which are able to provide full support to the weight of the units. If not, the units may collapse and impose danger.
  • Observe the rules and regulations of the electrical installation and the methods described in the installation manual when dealing with the electrical work. Use power cables approved by the authorities of your country.
    Be sure to use specified circuit. A short circuit and fire may occur due to the use of low quality wire or improper work.
  • Be sure to use the specified wire for connecting the indoor and outdoor units. Please ensure that the connections are tight after the conductors of the wire are inserted into the terminals. Improper insertion and loose contact may cause over-heating and fire.
  • Please use the specified components for installation work. Otherwise, the units may collapse or water leakage, electric shock and fire may occur.
  • Be sure to use the specified piping set for R41 OA. Otherwise, this may result in broken copper pipes or faults.
  • When installing or removing an air conditioner, only specified refrigerant (R410A) shall be allowed, do not allow air or moisture to remain in the refrigeration cycle. Otherwise, pressure in the refrigeration cycle may become abnormally high so that a rupture may be caused.
  • Be sure to ventilate fully if a refrigerant gas leak while at work. If the refrigerant gas comes into contact with fire, a poisonous gas may occur. Be aware that refrigerants may not contain an odor.
  • After completion of installation work, check to make sure that there is no refrigeration gas leakage. If the refrigerant gas leaks into the room, coming into contact with fire in the fan-driven heater, space heater, etc., a poisonous gas may occur.
  • Unauthorized modifications to the air conditioner may be dangerous. If a breakdown occurs please call a qualified air conditioner technician or electrician. Improper repairs may result in water leakage, electric shock and fire, etc.
  • Be sure to install a ground fault circuit interrupter. Failure to install a ground fault circuit interrupt may result in electrical shocks, or fire.
  • If you need to add refrigerant, please contact your local distributor.


  • A circuit breaker or fuse must be installed. Without a circuit breaker or fuse the danger of electric shock exists. The external switch shall be incorporated to completely disconnect from power supply. It should disconnect all poles, and a contact separation of at least 3mm must be present.
  • Do not install the unit near a location where there is flammable gas. The outdoor unit may catch fire if flammable gas leaks around it.HITACHI-RAM-SJ24H3NV-Split-Unit-Air-Conditioner-01
  • Do not install the indoor unit in a machine shop or kitchen where vapor from oil or its mist flows to the indoor unit. The oil will deposit on the heat exchanger, thereby reducing the indoor unit performance and may deform and in the worst case, break the plastic parts of the indoor unit.
  • Please ensure smooth flow of water when installing the drain hose.
  • Piping shall be suitable supported with a maximum spacing of 1 m between the supports.
  • In order to avoid a hazard due to inadvertent resetting of the THERMAL CUT-OUT, this appliance must not be supplied through an external switching device. such as timer or connected to a circuit that is regularly switched on and off by the utility.


  • Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer. Any unfit method or using incompatible material may cause product damage, burst and serious injury.
  • Do not pierce or burn as the appliance/pipe-work is pressurized. Do not expose the appliance/pipe-work to heat, flame, sparks, or other sources of ignition. Else, it may explode and cause injury or death.


  • This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.
  • Children should be supervised to ensure that they do not play with the appliance.
  1. Proper place for installation
    1. Outdoor unit
      1. Keep the space around the unit for maintenance and avoiding the effects of hindrance for normal ventilation of the unit.
      2. Keep the space around the unit for maintenance and avoiding the effects of hindrance for normal ventilation of the {2) The unavoidably, northern or some eastern blind side should of the be set building up for is the better unit. to (In install. this At case, the the installation blind must on not the obstruct southern the or western ventilation side of the unit.)
      3. You’d better not put the unit at a place where is full of dirt and at a place where is wet in the rain.
      4. Place as near as possible to the indoor unit.
      5. Install the unit in a stable place to minimize vibration or noise.
      6. After arranging the cords and pipes, secure them in place.
        • This appliance must be grounded.
        • Power is supplied through outdoor unit, do not connect power source to indoor unit.
  2. In the electrical installation a separator with a contact gap of more than 3mm has to be installed. During cleaning or service the set has to be switched off with this separator.

The Choice of Mounting Site (Please note the following matters and obtain permission from customer before installation).


  • The Outdoor unit must be mounted at a location which can support heavy weight. Otherwise, noise and vibration will increase.


  • Do not expose the unit under direct sunshine or rain. Besides, ventilation must be good and clear of obstruction.
  • The air blown out of the unit should not point directly to animals or plants.
  • The clearances of the unit from top, left, right and front are specified in figure below. At least 3 of the above sides must be open air.
  • Be disturb sure the that the hot neighborhood. air blown out of the unit and noise do not
  • Do not install at a location where there is flammable gas, steam, oil and smoke.
  • The location must be convenient for water drainage.
  • Place the Outdoor unit and its connecting cord at least 1 m away from the antenna or signal line of television, radio or telephone. This is to avoid noise interference.
  • Do not install outdoor unit facing strong wind direction. It may damage the fan motor.
  • Do not install the outdoor unit in a place where small animals may build their nests. If small animal goes inside the unit and touches the electrical parts, failure of the unit, smoke or fire may be caused. Request your customer to keep the surrounding of the unit is clean.


    Do not allow air, etc. to get into refrigerant cycle (piping)
    Compressor must be stopped before removing refrigerant pipes. All service valve must be fully closed after pumping down operation.

Names of Outdoor Components 

No. Item Qty
(1) Bush
(2) Drain Pipe
(3) Bush

Dimension of Mounting Stand of the Outdoor unit
(unit: mm)


Figure showing the Installation of Outdoor Unit.


  • The Outdoor unit is charged with refrigerant for pipe length up to 30m. In case the pipe length is more than recommended length, add refrigerant R410A as below. Do not exceed the maximum pipe length.
  • Installation of pipe length less than minimum pipe length requirement 5m may generate an abnormal sound.

Flare connection only at outside of building


Height difference
Height difference between indoor units should not be more than Sm


Piping length 


(L 1 + L2 + L3) = Maximum 60m
Minimum piping length for each indoor unit is Sm.
Maximum piping length for one indoor unit is 2Sm.
In case the pipe length is more than 30m, add refrigerant R41 OA at 12 gram per every meter exceeds.


  • To the outdoor unit, up to three indoor units can be connected until the total value of each units’ capacity reaches 1 O.SkW.
  • The pipe connection ports of the outdoor unit and connectable indoor units are shown above.


  • Make sure to connect to two or three indoor units.

Flare adaptor for piping
The indoor flare units. adaptor for piping is required depending on combination of  indoor units.

  • 09.52 (3/8′) > 0 12.7 (1/2″)
    Parts number TA261D-4 001
  • o12.7(1/2″)09.52 (3/8″)
    Parts number TA261D-6 002


  • Please mount the Outdoor unit on stable ground to prevent vibration and increase of noise level.
  • Decide the location for piping after sorting out the different types of pipe available.
  • When removing side cover, please pull the handle after undoing the hook by pulling it downward.



  • There are holes on the base of Outdoor unit for condensed water to exhaust.
  • In order to flow condensed water to the drain, the unit is installed on a stand or a block so that the unit is 100mm above the ground as shown figure. Join the drain pipe to one hole.
  • At first insert one portion of the hook to the base (Portion A), then pull the drain pipe in the direction shown by the arrow while inserting the hook into the base. After installation, check whether the drain pipe cling to the base firmly.


When Using and Installing In Cold Areas
When the air conditioner is used in low temperature and in snowy conditions, water from the heat exchanger may freeze on the base surface to cause poor drainage. When using the air conditioner in such areas, do not install the bushings. Keep a minimum of 250mm between the drain hole and the ground. When using the drain pipe, consult your sales agent.

  • For more details, refer to the installation Manual for Cold Areas.


  1. Preparation of Pipe
    • Use a pipe cutter to cut the copper pipe.
      • Jagged edge will cause leakage.
      • Point the side to be trimmed downwards during trimming to prevent copper chips from entering the pipe.
    • Before flaring, please put on the flare nut.
  2. El Pipe Connection
    In case of removing flare nut of an Indoor unit, first remove a nut of small diameter side, or a seal cap of big diameter side will fly out. Prevent water from entering into the piping when working.
  3. Removal Of Air From The Pipe And Gas Leakage Inspection


Procedures of using Vacuum Pump for Air Removal
  1. As shown in right figure, remove the cap of valve core. Then, connect the charge hose. Remove the cap of valve head. Connect the vacuum pump adapter to the vacuum pump and connect the charge hose to the adapter.
  2. Fully tighten the “Hi” knob of the manifold valve and completely unscrew the “Lo” knob. Run the vacuum pump for about 10~15 minutes, then completely tighten the “Lo” knob and switch off the vacuum pump.
  3. Remove the charge hose and tighten the cap of valve core. Check the cap’s periphery if there is any gas leakage.
  4. Completely unscrew the spindle of the service valve in anti-clockwise direction to allow the flow of refrigerant (using Hexagonal Wrench key).
  5. Re-cap the service valve and tighten using wrench. Check the cap’s periphery if there is any gas leakage. The task is then completed.

When the meter reaches – 101 KPa (-76cmHg) during pumping, fully tighten the Manifold Valve.


When pumping starts, slightly loosen the flare nut to check of air sucked in.
Then tighten the flare nut.



  • Prevent moisture from entering pipe connection.
  • Refrigerating machine oil not be applied to the outside of the flare.
    When refrigerating machine oil is applied to the outside of the flare, excessive tightening of the flare nut, cracking of the flare nut, destruction of the flare and gas leakage may occur.
  • When using the control valve, do not use deteriorated packing. And, do not overtighten the steering wheel.
    Gas leakage from the service valve part, stagnation, touching lire, rarely cause ignition.

( Gas Leakage Inspection )
Please use gas leakage detector to check if leakage occurs at the connection of Flare nut as shown on the right.
If gas leakage occurs, further tighten the connection to stop leakage. (Be sure to use R41 OA detector)




Procedures of Wiring

  1. Installation procedure and notice Especially, the selection of installation place need great care for the split type air conditioner, because it is very difficult to move from place to place after the first installation.
    1. Wiring
      1. Connect the electrical wiring between the Indoor and Outdoor unit, as shown in Fig. 1-1. Never connect the wiring by mistake. In case of wrong connection, the unit does not operate properly and it may cause malfunction.
    2. Connection of the connecting cords and power cord
      1. Cut off the connecting cord, the power cord and strip the insulation of the wire, as shown in Fig. 1-2.
        Detail of Cutting the Connecting Cord HITACHI-RAM-SJ24H3NV-Split-Unit-Air-Conditioner-19
      2. Connect the connecting cord and power cord to the terminal board. (Fig. 1-3)


  • The naked part of the wire core should be 10mm and fix it to the terminal tightly. Then try to pull the individual wire to check if the contact is tight. Improper insertion may burn the terminal.
  • Be sure to use only wire specified for the use of air-conditioner.
  • Please refer to the manual for wire connection and the wiring technique should meet the standard of the electrical installation.
  • There is an AC voltage drop between the Land N terminal if the power is on. Therefore, be sure to remove the plug from its socket.

Wiring of The Outdoor Unit 

  • Please remove the side cover for wire connection.


  • If you cannot close the side cover due to the connecting cord, please tidy up the wiring for spacing at front panel.
  • Be sure that the hooks of the side cover is properly fixed to avoid water penetration. Otherwise water leakage may occur and this causes short circuit or faults.
  • The connection cord should not to service valve and pipe to avoid possibilities of burn. (It become high temperature in heating operation.)
  • The appliance incorporates an earth connection for functional purpose only.

Checking for the electric source and the voltage range 

  • Before installation, the power source must be checked and necessary wiring work must be completed. To make the wiring capacity proper, use the wire gauge list below for the wiring from house distribution fuse box to the outdoor unit in consideration of the locked rotor current.
  • Investigate the power supply capacity and other electrical conditions at the installing location.
    Depending on the model of room air conditioner to be installed, request the customer to make arrangements for the necessary electrical work etc.
    The electrical work includes the wiring work up the outdoor unit . In localities where electrical conditions are poor, use of a voltage regulation is recommended.
  • Install outdoor for the room air conditioner within the reaching range of the line cord.

For (Power cord – L, N, Earth)

  • Cable type  Wire cross-section
  • 3 Core 12AWG (3.3mm2)

For (Connecting cord – 1, 2, 3, Earth)

Cable type Wire cross-section Cable length
4 Core 1BAWG (0.8mm2) up to 25m


  • Connect the Connecting Cord to “Indoor 1 (1, 2, 3) for indoor unit 1, “Indoor 2 (1, 2, 3) for indoor unit 2, “Indoor 3 (1, 2, 3) for indoor 3.

Arrange power cord so they do not touch service valve.

  • Type of grounding rod  Length
  • SP-EB-2  900mm


  • The supply cord of appliances for outdoor use shall be between 1.5m & 3m long and shall be either an EXTRA HARD USAGE or a HARD USAGE CORD.


  • Circuit Breaker
  • 25A

Be sure to install a ground fault circuit interrupter. (One that can handle higher harmonics.)
(This unit uses an inverter. Therefore, a ground fault circuit interrupter capable of handling higher harmonics must be used in order to prevent the ground fault c1rcu1t interrupter malfunctioning). _


Insulation And Maintenance Of Pipe Connection
  • The connected terminals should be completely sealed with heat insulator and then tied up with rubber strap.
  • Please tie the pipe and power line together with vinyl tape as shown in the figure showing the installation of Indoor and Outdoor units. Then fix their position with holders.
  • To enhance the heat insulation and to prevent water condensation, please cover the outdoor part of the drain hose and pipe with insulation pipe.
  • Completely seal any gap with putty.


Power Source And Operation Test

Power Source

  • Please use a new socket. Accident may occur due to the use of old socket because of poor contact.
  • Please plug in and then remove the plug for 2 -3 times. This is to ensure that the plug is completely plugged into the socket.
  • Keep additional length for the power cord and do not render the plug under external force as this may cause poor contact.
  • Do not fix the power cord with U-shape nail.

Operation Test

  • Please ensure that the air conditioner is in normal operating condition during the operation test.
  • Explain to your customer the proper operation procedures as described in the user’s manual.
  • If the indoor unit does not operate, check to see that the connections are correct.


  • Trial run should be conducted on one unit at a time to check for incorrect wiring of connecting cord.

Documents / Resources

HITACHI RAM-SJ24H3NV Split Unit Air Conditioner [pdf] Instruction Manual
RAM-SJ24H3NV Split Unit Air Conditioner, RAM-SJ24H3NV, Split Unit Air Conditioner, Unit Air Conditioner, Air Conditioner, Conditioner

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