Hitachi YUTAKI S Series, RWM-1.5R1E, RWM-1.5R3E, RWM-1.5R3N Manual

GENERAL DIMENSIONS

Minimum floor area for R32 units

Please refer to outdoor unit installation manual for charge calculation.

1. Check the refrigerant charge:
   1. If the refrigerant charge is <1.84 kg, no minimum area is required.
   2. If the refrigerant charge is >1.84 kg, check the Table 1 for minimum floor area (A_min).
2. Calculate the room area:
   1. Check the Table 1 to see the corresponding minimum room area (room A) according to the maximum refrigerant charge (m_c) and the installation height (H₀).
   2. In case that the room area is not complying the minimum area requirement, check for an adjacent room (room B).
3. Determine total floor area of room A and room B:
   1. Calculate the area of room B adjacent to the room A.
   2. Determine if the A_{min total} (A_{min total} = Room A + Room B) based on the total refrigerant charge (m_c) from Table 1.
   3. The total floor area both room A and room B must exceed A_{min total}.
4. Determine Minimum Venting Opening Area (VA_min) for Natural Ventilation
   • For connected rooms and natural ventilation, the following conditions must be satisfied:
   • High-Level Openings: Openings located more than 300 mm above the floor will not count towards the required minimum ventilation area (A_nv,min).
   • Low-Level Openings: At least half of the required ventilation area (A_nv,min) must be situated below 200 mm from the floor.
   • Lowest Point of Openings: The base of the lowest openings must be no higher than the release point of the refrigerant and should not exceed 100 mm from the floor.
   • Permanent Openings: Ventilation openings must be permanent and cannot be sealed.
   • Connecting Room Openings: Openings that connect rooms must have a height of at least 20 mm between the wall and the floor.
   • Additional Higher Opening: A second, higher opening is required. This additional opening should be at least 50% of the A_nv,min and positioned no less than 1.5 meters above the floor.

NOTE
In case of not able to proceed with any of option above. Please consider to select other outdoor unit combination option (reduce piping length, monobloc systems, etc...).

NOTE
The minimum opening area for natural ventilation between room A and room B is calculated by the following formula:
A_nv,min1= 1.51 x (mc-m_max) x (A_roomA/m_max)^˄(1/2)
m_max= 0.571 x h₀x (A_roomA)^˄(1/2)
Where:

• A_nv,min1:minimum opening for natural ventilation between room A and room B, in dm².
• A_roomA: room A area, in m².
• m_max: the allowable maximum refrigerant charge in the room A, in kg.
• Mark "-" in the above table indicates that the room A is large enough for installation without adjacent room B.
• For intermediate refrigerant charges, room A area and installation height, select the higher charge value, the smaller room area and the lower height value to choose the A_nv,min1. For example, if the refrigerant charge is 2.9 kg, room A area is 8 m² and the installation height is 1.85 m, then A_nv,min1 =1.08 dm² according to the table (h₀=1.7 m)

Service space

Units in mm.
H: 1200~1500 mm
Recommended unit height for proper access to the control unit panel (Unit controller).
h: 350 mm
Minimum unit height for installing the shut-off valves and the first bending pipe line.

REFRIGERANT AND WATER PIPING

General notes appliance with R32 refrigerant

This symbol displayed on the unit indicates that this appliance is filled with R32, an odourless flammable refrigerant gas with low burning velocity (A2L class pursuant to ISO 817). If the refrigerant is leaked, there is a possibility of ignition if it enters in contact with an external ignition source.
Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer.
The appliance shall be stored in a room without continuously operating ignition sources (for example: open flames, an operating gas appliance or an operating electric heater).
Do not pierce or burn.
Be aware that refrigerants may not contain an odour.

RISK OF EXPLOSION
The compressor must be stopped before removing the refrigerant pipes.
All service valves must be fully closed after pumping down operation.

	This symbol displayed on the unit indicates that this appliance shall be handled by authorized service personnel only, referring to the Installation Manual.
	This symbol displayed on the unit indicates that there is relevant information included in the Operation Manual and/or Installation Manual.
	For more information, see the Installation and Operation Manual.

Make sure that unit installation and refrigerant piping installation comply with applicable legislation in each country. Also, in Europe, EN378 must be complied, as it is the applicable standard.

R410A Refrigerant circuit

‹Precautions in the event of gas refrigerant leaks
The installers and those responsible for drafting the specifications are obliged to comply with local safety codes and regulations in the case of refrigerant leakage.

• Check for refrigerant leakage in detail. If a large refrigerant leakage occurred, it would cause difficulty with breathing or harmful gases would occur if a fire were in the room.
• If the flare nut is tightened too hard, it may crack over time and cause refrigerant leakage.

‹Maximum permitted concentration of HFCs
The refrigerant R410A (charged in the outdoor unit) is an incombustible and non-toxic gas. However, if leakage occurs and gas fills a room, it may cause suffocation.
The maximum permissible concentration of HFC gas according to EN378-1 is:

The minimum volume of a closed room where the system is installed to avoid suffocation in case of leakage is:

The formula used for the calculation of the maximum allowed refrigerant concentration in case of refrigerant leakage is the following:

R: Total quantity of refrigerant charged (kg)
V: Room volume (m³)
C: Refrigerant concentration
If the room volume is below the minimum value, some effective measure must be taken account after installing to prevent suffocation in case of leakage.

Refrigerant piping and refrigerant charge

Refrigerant piping length between indoor unit and outdoor unit (R32 units)
The unit installation and refrigerant piping should comply with the relevant local and national regulations for the designed refrigerant.
Due to R32 refrigerant and depending on final refrigerant charge amount, a minimum floor area for installation must be considered.

• If total refrigerant charge amount <1.84kg, there are no minimum floor area requirements.
• If total refrigerant charge amount ≥1.84kg, there are minimum floor area requirements to be checked.

ELECTRICAL AND CONTROL SETTINGS

General check

• Make sure that the following conditions related to power supply installation are satisfied:
  • The power capacity of the electrical installation is large enough to support the power demand of the YUTAKI system (outdoor unit + indoor unit + DHW tank (if apply)).
  • The power supply voltage is within ±10% of the rated voltage.
  • The impedance of the power supply line is low enough to avoid any voltage drop of more than 15% of the rated voltage.
• Following the Council Directive 2014/30/EU, relating to electromagnetic compatibility, the table below indicates the Maximum permitted system impedance Z_max at the interface point of the user's supply, in accordance with EN 61000-3-11.

NOTE
The data corresponding to DHW tank heater is calculated in combination with the domestic hot water tank accessory "DHWT-(200/300)S-3.0H2E".
The status of Harmonics for each model, regarding compliance with EN 61000-3-2 and EN 61000-3-12 is as follows:

Check to ensure that existing installation (mains power switches, circuit breakers, wires, connectors and wire terminals) already complies with the national and local regulations.
The use of the DHW tank heater is disabled as setting. If it is desired to enable the DHW tank heater operation during normal indoor unit operation, adjust the DSW4 pin 3 of the PCB1 to the ON position and use the adequate protections.

System wiring diagram

Connect the units according to the following electric diagram:

Wiring size and minimum requirements of the protection devices

• Check to ensure that the field supplied electrical components (mains power switches, circuit breakers, wires, connectors and wire terminals) have been properly selected according to the electrical data indicated on this chapter and they comply with national and local codes. If it is necessary, contact with your local authority in regards to standards, rules, regulations, etc.
• Use a dedicated power circuit for the indoor unit. Do not use a power circuit shared with the outdoor unit or any other appliance.

Use wires which are not lighter than the polychloroprene sheathed flexible cord (code designation 60245 EN 57).

• Ensure specifically that there is an Earth Leakage Breaker (ELB) installed for the units (outdoor and indoor unit).
• If the installation is already equipped with an Earth Leakage Breaker (ELB), ensure that its rated current is large enough to hold the current of the units (outdoor and indoor unit).

NOTE

• The data corresponding to DHW tank heater is calculated in combination with the domestic hot water tank accessory "DHWT-(200/300)S-3.0H2E".
• Electric fuses can be used instead of magnetic Circuit Breakers (CB). In that case, select fuses with similar rated values as the CB.
• The Earth Leakage Breaker (ELB) mentioned on this manual is also commonly known as Residual Current Device (RCD) or Residual Current Circuit Breaker (RCCB).
• The Circuit Breakers (CB) are also known as Thermal-Magnetic Circuit Breakers or just Magnetic Circuit Breakers (MCB).

Transmission wiring between outdoor and indoor unit

• The transmission is wired to terminals 1-2.
• The H-LINK II wiring system requires only two transmission cables that connect the indoor unit and the outdoor unit.
  
• Use twist pair wires (0.75 mm²) for operation wiring between outdoor unit and indoor unit. The wiring must consist of 2-core wires (Do not use wire with more than 3 cores).
• Use shielded wires for intermediate wiring to protect the units from noise interference, with a length of less than 300 m and a size in compliance with local codes.
• In the event that a conduit tube for field-wiring is not used, fix rubber bushes to the panel with adhesive.

Ensure that the transmission wiring is not wrongly connected to any live part that could be damaged the PCB.

UNIT INSTALLATION

General notes

Selection of the installation location
The indoor unit of the split system with air to water heat pump must be installed following these basic requirements:

• The indoor unit is intended to be installed in an indoor place and for ambient temperatures ranging 5~30°C. The ambient temperature around the indoor unit must be >5°C to prevent water from freezing.
• The unit is prepared to be wall mounted (wall bracket is factory supplied), so make sure that selected wall is flat and is made of a non-combustible surface, strong enough for supporting the indoor unit weight.
• Be sure to maintain the recommended servicing space for future unit servicing and guarantee enough air circulation around the unit (See "Minimum floor area for R32 units" section).
• Take into account that two shut-off valves (factory supplied) must be installed at the indoor unit inlet/outlet connections.
• Keep water draining provisions. The safety valve and the air purge are provided with a drain pipe which are located at the bottom side of the unit.
• In the event of installing the "Cooling kit" accessory, the installer is responsible for proper installation and draining.
• Protect the indoor unit against the entry of small animals (like rats) which could making contact with the wires, the drain pipe, electrical parts and may damage unprotected parts, and at the worst, a fire will occur.
• Install it in a no-frost environment.
• Do not install the indoor unit in a location with very high humidity.
• Do not install the indoor unit where electromagnetic waves are directly radiated to the electrical box.
• Install the unit in a place where in case of water leakage, any damage to the installation space cannot be produced.
• Install noise filter when the power supply emits harmful noises.
• To avoid fire or explosion, do not install the unit in a flammable environment.
• The air to water heat pump must be installed by a service technician. The installation must comply with local and European regulations.
• Try to avoid to put any objects or tools above the indoor unit.

Unpacking

All units are supplied with a wooden base, packed by a cardboard box and plastic bag.
Firstly to unpack it, place the unit on the assembly area as close as possible to its final installation location, to avoid damages in transport. Two persons are required.

1. Cut the strapping bands and remove the adhesive tapes.
2. Remove the carton assembly and then the plastic bag around the unit.
3. Unscrew the 4 screws which fix the unit to the wooden base.
4. Remove the indoor unit from the wooden base and place it carefully on the floor, as near as possible to its final location.
   

• Be careful with the Instruction manual and the factory-supplied accessories box located besides the unit.
• Two people are required when lifting because of the weight of the unit.

Factory-supplied indoor unit components

Accessory	Image	Qty.	Purpose
Shut-off valve 1.5-6 HP: 1" 8/10 HP: 1-1/4"		2	To make easier the installation work in the space heating water inlet/outlet connections. For a better servicing.
Gasket		4	Two gaskets for each space heating connections (inlet/outlet)
Power connection bridge		1	To make easier the installation work in power terminal in case of ~230V connections
Wall support		1	For hanging the unit on the wall
Instruction manual		1	Basic instructions for the installation of the device.
Instruction manual		1	Additional safety manual for R32 refrigerant air conditioner and heat pump according to IEC 60335-2-40:2022 Only for RWM-(1.5-6.0)R3E

NOTE

• The previous accessories are supplied inside the packing assembly (besides the indoor unit).
• Additional refrigerant piping (field supplied) for connections to outdoor unit needs to be available.
• If some of these accessories are not packed with the unit or any damage to the unit is detected, please contact your dealer.

Indoor unit main parts (Descriptions)

1. Indoor unit service cover
2. Unit controller frame
3. Unit controller
4. Piping connections
5. IOT receiver

Installation of Indoor unit

NOTE
Please, try to perform all this procedure following all the steps in the exact order in which they are presented below.

Installation procedure

1. Wall mounting procedure
2. Space heating pipes connection
3. Drain pipes connection
4. Refrigerant piping connection
5. Power and transmission wiring connection
6. Cover assembly
7. Test and check

Wall mounting procedure

1. Fix the wall support (factory-supplied accessory) to the wall using appropriate plugs and screws. Make sure that the wall support is completely levelled.
   
2. Hang the indoor unit on the wall support (at least two persons are required in order to lift the unit because of its weight).
   
3. Fix the indoor unit at the bottom side using the 4 screws which had been previously removed during the unpacking procedure.
   

Power and transmission wiring connection

‹Safety instructions
NOTE
Check the requirements and recommendations in the chapter "Electrical and control settings".

• Do not connect the power supply to the indoor unit prior to filling the space heating circuit (and DHW circuit if it were the case) with water and checking water pressure and the total absence of any water leakage.
• Do not connect or adjust any wiring or connections unless the main power switch is OFF.
• When using more than one power source, check and ensure that all of them are turned OFF before operating the indoor unit.
• Avoid wiring installation in contact with the refrigerant pipes, water pipes, edges of plates and electrical components inside the unit to prevent damage, which may cause electric shock or short circuit.

• Use a dedicated power circuit for the indoor unit. Do not use a power circuit shared with the outdoor unit or any other appliance.
• Make sure that all wiring and protection devices are properly selected, connected, identified and fixed to the correspondi ng terminals of the unit, specially the protection (earth) and power wiring, taking into account the applicable national and local regulations. Establish proper earthing; Incomplete earthing may cause electrical shock.
• Protect the indoor unit against the entry of small animals (like rodents) which could damage the drain pipe and any internal wire or any other electrical part, leading to electric shock or short-circuit.
• Keep a distance between each wiring terminal and attach insulation tape or sleeve as shown in the figure.
  

‹Connection procedure
Access to the electrical box before performing the next steps:

1. Using the appropriate cable, connect the power circuit to the appropriate terminals as shown on the wiring label and the illustration below. Connect the power supply cables to the terminal board (TB1), and the earth conductor to the earth screw in the electrical box plate.
   
   (*) For a ~230 V power supply, use the power connection bridge provided in the accessory bag, following these instructions:
   
2. Connect the transmission wires between outdoor and indoor unit to the terminals 1 and 2 on the terminal board 2 (TB2).
3. Carry out the necessary electrical connections of the optional accessories using the terminal board 2 (TB2). Consult its label for a better understanding.
4. Pass the electrical wiring from the TB1 and TB2 to the lateral holes of the electrical box. Then, fix the cables to the cord bands located at the right side. Finally, take the cables out through the bottom side of the unit.

CSNET Home app connection

Configuring the YUTAKI unit from a mobile device is possible. Download the CSNET Home application from the Apple Store or Google Play Store. The application is also available at www.csnetmanager.com. Follow the instructions within the app to connect the unit.
www.csnetmanager.com

SAFETY

Applied symbols

During normal heat pump system design work or unit installation, greater attention must be paid in certain situations requiring particular care in order to avoid damage to the unit, the installation or the building or property.
Situations that pose a risk to the safety of those in the surrounding area or to the unit itself are clearly indicated in this manual.
A series of special symbols are used to clearly identify these situations.
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 in the proximities of the unit.

In the texts following the danger symbol you can also find information on safety procedures during unit installation.

• 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.
• Not taking these instructions into account could lead to unit damage.

In the texts following the caution symbol you can also find information on safety procedures during unit installation.
NOTE

• 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.

Additional information about safety

• DO NOT CONNECT THE POWER SUPPLY TO THE INDOOR UNIT PRIOR TO FILLING THE SPACE HEATING CIRCUIT (AND DHW CIRCUIT IF IT WERE THE CASE) WITH WATER AND CHECKING WATER PRESSURE AND THE TOTAL ABSENCE OF ANY WATER LEAKAGE.
• Do not pour water over the indoor unit electrical parts. If the electrical components are in contact with water a seri ous electrical shock will take place.
• Do not touch or adjust the safety devices inside the air to water heat pump. If these devices are touched or adjusted, a serious accident can take place.
• Do not open the service cover or access inside the air to water heat pump without disconnecting the main power supply.
• In case of fire Turn OFF the main switch, put out the fire at once and contact your service contractor.
• It must ensure that the air to water heat pump cannot op erate accidentally without water neither with air inside hydraulic system.

• Do not use any sprays such as insecticide, lacquer, hair spray or other flammable gases within approximately one meter from the system.
• If installation circuit breaker or the unit fuse is often activated, stop the system and contact your service contractor.
• Do not make service or inspections tasks by yourself. This work must be performed by a qualified service person.
• 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.
• Do not let any foreign body into the water inlet and outlet piping of the air to water heat pump.

• The supplementary information and ErP data about the purchased products is available through the QR printed in the front cover. In case that no access to the website or files are not readable, please contact your Hitachi dealer or distributor.
• PLEASE READ THE MANUAL AND DOWNLOADED FILES THROUGH THE QR CAREFULLY BEFORE STARTING TO WORK ON THE INSTALLATION. Failure to observe the instructions for installation, use and operation described in this documentation may result in operating failure including potentially serious faults, or even the destruction of the air to water heat pump system.
• Verify, in accordance with the manuals which appear in the outdoor and indoor units, that all the information required for the correct installation of the system is included. If this is not the case, contact your distributor.
• Hitachi pursues a policy of continuous improvement in product design and performance. The right is therefore reserved to vary specifications without notice.
• Hitachi cannot anticipate every possible circumstance that might involve a potential hazard.
• This air to water heat pump has been designed for standard water heating for human beings only. Do not use this for other purposes such as for drying clothes, heating foods or for any other heating process (except swimming pool).
• No part of this manual may be reproduced without written permission.
• If you have any questions, contact your service contractor of Hitachi.
• Check and make sure that the explanations of each part of this manual correspond to your air to water heat pump model.
• Refer to the models codification to confirm the main characteristics of your system.
• Signal words (NOTE, DANGER and CAUTION) are used to identify levels of hazard seriousness. Definitions for identifying hazard levels are provided in initial pages of this document.
• The operation modes of these units are controlled by the unit controller.
• This manual should be considered as a permanent part of the air to water heat pump. It gives a common description of and information for this air to water heat pump which you operate as well as for other models.
• Keep the water temperature of the system above the freezing temperature.
• Water temperature (min/max): 5°C/65°C
• Water pressure (min/max): 0.1 MPa/0.3 MPa
• This equipment must be connected to the water main.
• lf the domestic cold water entry pressure is higher than the equipment's design pressure (1 MPa), pressure reducer must be fitted with a nominal value of 0.7 MPa.