Specifications in this manual are subject to change without notice in order that Hitachi may bring the latest innovations to their customers.Whilst every effort is made to ensure that all specifications are correct, printing errors are beyond Hitachi’s control; Hitachi cannot be held responsible for these errors.


  • This product shall not be mixed with general house waste at the end of its life and it shall be retired according to the appropriated local or national regulations in a environmentally correct way.
  • Due to the refrigerant, oil and other components contained in Air Conditioner, its dismantling must be done by a professional installer according to the applicable regulations. Contact to the corresponding authorities for more information.


Applied symbols

During normal air conditioning system design work or unit installation, greater attention must be paid in certain situations requiring particular care in order to avoid injuries and damage to the unit, the installation, the building or to those in the surrounding area. These situations will be clearly indicated in this manual. Signal words (NOTE, DANGER and CAUTION) are used to identify levels of hazard seriousness. Definitions for identifying hazard levels are provided below with their respective signal words. Pay close attention to these symbols and to the messages following them, as your safety and that of others depends on it.


  • The text following this symbol contains information and instructions relating directly to your safety in addition to hazards or unsafe practices which could result in severe personal injuries or death.
  • Not taking these instructions into account could lead to serious, very serious or even fatal injuries to you and others standing near the unit.


  • The text following this symbol contains information and instructions relating directly to your safety in addition to hazards or unsafe practices which could result in minor personal injury or product or property damage.
  • Not taking these instructions into account could lead to minor injuries to you and others in the proximities of the unit.
  • Not taking these instructions into account could lead to unit damage.


  • The text following this symbol contains information or instructions that may be of use or that require a more thorough explanation.
  • Instructions regarding inspections to be made on unit parts or systems may also be included.


HITACHI cannot anticipate every possible circumstance that might involve a potential hazard.


  • DO NOT perform installation work and electrical wiring connection by yourself. Contact your HITACHI distributor or dealer and ask them for installation work and electrical wiring by service person.


  • DO NOT install the indoor unit, outdoor unit, controller and cable at such places as;
    • Where there is oil vapor and the oil is dispersed.
    • Where the hot springs are near (in a sulfuric environment).
    • Where generation, flowing, staying or leaking of flammable gas is detected.
    • Where the sea is near (in the salty environment).
    • An acid or alkaline environment.
  • DO NOT install the indoor unit, outdoor unit, controller and cable within approximately 3 meters from strong electromagnetic wave radiators such as medical equipment. In case that the controller is installed in a place where there is electromagnetic wave radiation, shield the controller and cables by covering with the steel box and running the cable through the metal conduit tube.
  • In case that there is electric noise at the power source for the indoor unit, provide a noise filter.
  • Use specified cables to connect between indoor unit and remote control switch. Selecting incorrect cables may lead to fire or electrical shock.


  • The installer and system specialist shall comply with local regulations or standards for the safety. The following standards may be applicable, if local regulations are not available. International Organization for Standardization, ISO5149 or European Standard, EN378 or Japan Standard, KHKS0010.
  • Perform electrical work according to the Installation Manual. As for the electrical wiring work and check, turn OFF the main power supply before opening/closing the service cover of indoor unit. If service cover is opened with main power supply left on, it may result in an electrical shock.
  • It is assumed that this renewal kit and the system will be installed, operated and serviced by English speaking people. If this is not the case, the customer should add safety such as and operating signs in the native language for non English speakers.
  • This manual should be considered as a permanent part of the air conditioning equipment system and should remain with the air conditioning equipment.
  • This appliance must be used only by adult and capable people, having received the technical information or instructions to handle this appliance properly and safely.
  • Children should be supervised to ensure that they do not play with the appliance.
  • Important: read and understand this manual before using and install this competent.

If you have any questions, contact your HITACHI distributor or dealer.


  1. The pressure of the refrigerant R410A is 1.4 times higher than that of the refrigerant R22 or R407C. The refrigerant R410A and its refrigerant oil are more susceptible to impurities such as moisture, oxide film and grease. During installation work, therefore, make sure that any moisture, dust, different refrigerant or different refrigerant oil will not enter the refrigerant cycle.
  2. Use the specified tool exclusively for the refrigerant R410A in order to prevent any different refrigerant or refrigerant oil from entering the refrigerant cycle.
  3. If you use the specified refrigerant pipe exclusively for the refrigerant R410A, perform the flaring work as shown below.
  4. Existing outdoor and indoor units for R22 or R407C can not be used.
  5. For systems with several indoor units, branch pipes shall be changed to Hitachi-specified model.
  6. Special attention is required with regard of the piping thickness for R410A
  7. Existing pipes can be used without cleaning if the following conditions are satisfied:
    • The renewal kit shall be installed. (mandatory)
    • Maximum piping length shall be 50 m (If the pipe is longer than 50m, existing pipes can be used if cleaning is performed).
    • The capacity of the new unit must be equivalent to the one previously installed.
    • Existing pipes shall be free of corrosion, cracks, scratches or deformations.
    • Dirt inside the pipes shall not be noticeable.
    • The specifications of piping, flare nuts, gaskets, etc. shall be compliant.
    • Flare shall be reprocessed.
    • Piping airtightness and vacuuming shall be ensured in the same way as with new piping.
  8. When existing Air-Conditioner is a product of another manufacturer. Existing pipes made by other manufacturer can also be used if the following conditions are satisfied:
    • For systems with several indoor units, branch pipes shall be changed to a Hitachi-specified model.
    • Please perform a pipe cleaning.

CAUTION: Recovering R22 and R407C is mandatory to remove an existing air conditioner and piping. Do not vent into the atmosphere.


Flare Nut Dimension B


Diameter (Ød) R407C, R22 R410A
6.35 17 17
9.52 22 22
12.7 24 26 *
15.88 27 29 *
  •  The face-to-face distance (B) of flare nuts for R410A is made longer.

Flaring Dimension


  Copper Pipe Diameter Copper Pipe Thickness

Diameter (Ød)

A +0 Thickness
R407C, R22  


R407C, R22  


6.35 9.0 9.1 0.8 0.8
9.52 13.0 13.2 0.8 0.8
12.7 16.2 16.6 0.8 0.8
15.88 19.4 19.7 1.0 1.0

NOTE: Make sure to use the specified pipe.

Flared connection mounting

  • Apply a thin layer of oil to the cone opening for refrigeration systems. Line up the end of the flared pipe to face the fitting to which it is to be threaded.
  • Gently rest the female cone on the male cone and check that the measurement is correct. Keep the connection lined up with one hand and gently thread on the flare nut with the other.
  • Tighten the connection to the corresponding tightening torque indicated in the table.
Nominal diameter Tightening torque
mm Inches
Ø 6.35 1/4 20 Nm
Ø 9.52 3/8 40 Nm
Ø 12.7 1/2 60 Nm
Ø 15.88 5/8 80 Nm


Check that the following items are packed before installation.


TRF-NP280U1/ TRF-NP335U2


  • O.U: Outdoor unit
  • I.U: Indoor unit


Installation Using the Existing Refrigerant Piping


  • Use non-flammable and non-toxic cleaning agent for cleaning the piping. Flammable cleaning agent may cause an explosion or a fire.
  • Open the window for ventilation during the installation. If not, it may result in an oxygen shortage.
  • Make sure that cleaning agent does not contact fire or reach a high temperature, as toxic gas will generate.


  • Make sure to collect cleaning agent after cleaning the piping. It is strictly prohibited to release Fluorocarbons into the atmosphere without any reason.
  • During heating operation, the maximum pressure on the existing piping must be less than the allowable pressure (3.6MPa). When using the existing piping with a diameter of Ø19.05, therefore, set No.4 pin of DSW2 on outdoor unit PCB to “ON” to keep the maximum pressure on the piping less than 3.6MPa.

By using this Renewal Kit TRF-NP Series, the existing piping can be used for a new air conditioner without cleaning the piping under the following conditions.

Conditions for using the existing refrigerant piping

  1. The total length of the existing refrigerant piping shall be up to 50m.
  2. The new UTOPIA Series air conditioner to be installed shall be for 12HP or less.
  3. Make sure to check that there are no scratches and dents on the surface of the existing refrigerant pipe nor smudges inside the pipe.
  4. The flare nut and the piping diameter shall be based on JIS (Japanese Industrial Standards). The thickness of copper pipe is indicated in the table below.
  5. Perform the flaring work of the existing refrigerant piping again before installation.
  6. Make sure to conduct an air-tight test and vacuuming of the piping.

Copper pipe thickness (mm)

Diameter (Ød)  




6.35 0.8 O Material
9.52 0.8 O Material
12.7 0.8 O Material
15.88 1.0 O Material
19.05 1.0 O Material
22.2 1.2 O Material
25.4 1.0 1/2H Material
28.58 1.0 1/2H Material


  • The fluorocarbons must be collected when removing the old air conditioner.
  • If the total length of the existing piping is over 50m, the renewal kit cannot be used. However, if cleaning work of the existing refrigerant piping is carried out, the existing refrigerant piping is available without renewal kit.

For using the piping made by other companies

The existing refrigerant piping of air conditioner made by other companies can be used for a new HITACHI air conditioner only if complying with the item “Conditions for Using the Existing Refrigerant Piping” and the following points.

  1. Use the branch piping (for 410A) specified by HITACHI. If using the branch piping made by other companies, make sure to check the followings.
    • The allowable pressure shall be 3.6MPa or more.
    • Set No.4 pin of DSW2 on outdoor unit PCB to “ON.” (This is not required if the allowable pressure of the branch piping is 4.15MPa or more.)
    • Y-shaped branches shall be adopted for branch pipes.
  2. If the system for the existing air conditioner is Gas Heat Pump System, clean the existing refrigerant piping before installation.

Mounting Position

Refer to Installation & Maintenance Manual of each Outdoor Unit for details.

Recommended renewal kit

  • External attachment to outdoor unit [Short pipe (local) + Kit + existing piping]
  • Internal attachment to outdoor unit [Kit + existing piping]
IVX Premium A B
RAS-(2/2.5)HVNP(1) TRF-NP63S1
RAS-(4-6)H(V)NP(1/2)E (TRF-NP160S1) TRF-NP160U1
RAS-(10/12)HNP(E) TRF-NP335U2
RAS-(3-6)H(V)NC(1/2)(E) TRF-NP160S1
RAS-(10/12)HNC(E) TRF-NP335U2

NOTE: Take care when deciding the mounting direction.

Piping Diameter
Strainer Diameter Outlet on TRF-NP63S1 TRF-NP160S1 TRF-NP160U1 TRF-NP280U1 TRF-NP335U2

for liquid pipe

O.U. Side          
  Ø6.35 Ø9.52 Ø9.52 Ø9.52 Ø12.7
I.U. Side          
  O.U. Side     Ø19.05 Ø19.05
for gas pipe   Ø12.7 Ø15.88 Ø15.88    
  I.U. Side     Ø25.4 Ø25.4
  • O.U: Outdoor unit
  • I.U: Indoor unit
Details of renewal kit


  • O.U: Outdoor unit
  • I.U: Indoor unit
Pipe/ Model/ TRF-NP63S1/ TRF-NP160S1


Pipe/ Model/ TRF-NP160U1


Pipe/ Model/ TRF-NP280U1


Pipe/ Model/ TRF-NP335U2


Renewal kit installation (Example)

RAS-(2/2.5)HVNP(1) – RAS-3HVNC(1)


RAS-3HVNP(1)E – RAS-(4-6)H(V)NCE




RAS-(4-6)H(V)NP(1)E – RAS-(8/10)HN(P/C)E




NOTE: Sizes (a) to (g) depend on the outdoor unit model.

  RAS-(2/2.5)HVNP(1) RAS-3HVNC(1) RAS-(4-6)H(V)NP(1)E RAS-8HN(P/C)E RAS-10HN(P/C)E RAS-12HN(P/C)
a 22 26 581 596 578 580
b 109 103 491 497 497 521
c 129 127 329 282 264 266
d 229 137 137 161
e 46 47 46
f 96 98 97
g 81 69 91

Cooling & Heating

  • Shimizu Factory, Hitachi-Johnson Controls Air Conditioning, Inc
  • 390, Muramatsu, Shimizu-ku
  • Shizuoka-shi. 4240926 – Japan


Copyright 2023 Johnson Controls-Hitachi Air Conditioning Technology (Hong Kong) Ltd.

PMEN0523 rev.0 – 02/2023 – A16381TTVF
Printed in Japan

Documents / Resources

HITACHI TRF-NP Renewal Kit [pdf] Instruction Manual
TRF-NP Renewal Kit, TRF-NP, Renewal Kit, Kit


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