Hitachi RASM-2VRE Manual

Yutaki M Typical Installation
With third party heating controls
Installation and setup
Monobloc System
Rev 1.1 January 11, 2022

This manual is designed to be a quick guide to the most common type of instal-
lation for a Hitachi Yutaki M Monobloc system.
This assumes heating via a buffer tank or low loss header, domestic hot water
via a cylinder with sensor pocket and immersion heater, 3 port diverting valve
and Secon remote room RF wireless programmable temperature controller.
In the above system the monobloc units functions are controlled by the units own controller
and this is only used by the technician not the end user.
The end user controls the heating demand using a wireless room controller and can use this
to set the room temperature at different times of the day.
The heat pump controls the domestic hot water temperature itself (including for an optional
sterilisation cycle) using the 3 way valve and is assisted by the immersion heater.
There is no electric heater inside the monobloc unit. An optional inline heater can be used.
The 3 way valve is a diverting, not a mixing valve. When unpowered it provides flow to the
buffer tank. When powered it cuts off flow to the buffer tank and diverts it to hot water.
A buffer tank or low loss header is necessary to provide thermal separation and cope with low
load conditions. In addition a buffer tank gives the thermal mass necessary to avoid freezing
the heat exchanger during defrost mode.
A magnetic filter should be fitted in the return pipework and a pressure gauge in the flow.
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Important—All piping
should be 28mm cop-
per as a minimum,
larger if plastic.
Flowsetter *
* Please note—the monobloc unit contains a strainer
so an external one is optional as is a flowsetter.
* A magnetic filter is mandatory for all installations.
Pressure Gauge
Heating System
Strainer & Filter *
Zone Valve
3 way valve
for dhw tank
Yutaki M Heat Pump
Hitachi PC-ARFHE
Wireless Base Station
Wireless Room Control

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Warranty
Please check the following before commencing startup as they are important conditions of the Hitachi warranty.
• A magnetic filter must be installed in the return pipe as close as possible to the system inlet. Do not
switch the system on without this.
• Power must be supplied to the unit for at least 8 hours before operation in order to heat the compressor
sufficiently for first use. Do not start the compressor up from cold or expensive failure may result.
• A buffer tank or low loss header should be used to create hydraulic separation and ensure a minimum
primary water volume of either 28 litres (single fan unit) or 38-55 litres (twin fan unit dependent on
model). If using a low lossheader then a volumising tank is probably required.
• The pipe diameter used must be no smaller than 28mm copper (larger if plastic). Contact Secon for advice
if the pipe length exceeds 10 metres or you are using plastic pipe.
• If glycol (anti-freeze) is used then this should be food safe and pre mixed before introduction and of the
correct strength for the system. This should be checked every year.
• The water quality should be tested against Hitachis requirements?
Part of the startup process involves checking the water flow rate. In order for the unit to operate at all then an
absolute minimum flow rates must be met, but for correct operation as designed then a water flow rate below
must be observed below.
Model
Min Flow Rate
Max Flow Rate
Minimum Water Content
RASM-2VRE
8.4 l/min
31.8 l/min
28lt
RASM-3VRE
10.0 l/min
35.0 l/min
28lt
RASM-4VNE
16.7 l/min
46.8 l/min
38lt
RASM-5VNE
18.4 l/min
50.1 l/min
46lt
RASM-6VNE
20.0 l/min
50.1 l/min
55lt
RASM-4NE
16.7 l/min
46.8 l/min
38lt
RASM-5NE
18.4 l/min
50.1 l/min
46lt
RASM-6NE
20.0 l/min
50.1 l/min
55lt
A commissioning sheet is available for download on the Secon renewable web site www.seconrenewables.com
and this should be filled in and returned to Hitachi within 28 days of commissioning. Also the unit should be
subject to an annual service by the installing contractor or another authorized service company to meet the
warranty conditions.

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Power Supply
Monobloc units require a single power supply
Power Supply sizes are -
Without Immersion Heater With Immersion Heater
Model
Max Amps
MCB Size
Min Cable Size
Max Amps
MCB Size
Min Cable Size
RASM-2VRE
12.7A
16A
2.5mm² x 3*
25.2A
32A
6mm² x 3*
RASM-3VRE
17.2A
20A
4mm² x 3*
29.7A
32A
6mm² x 3*
RASM-4VNE
31A
32A
6mm² x 3*
43A
50A
10mm² x 3*
RASM-5VNE
31A
32A
6mm² x 3*
43A
50A
10mm² x 3*
RASM-6VNE
31A
32A
6mm² x 3*
43A
50A
10mm² x 3*
RASM-4NE
14A/PH
20A-3PH
4mm² x 5*
27A/PH
30A-3PH
10mm² x 5*
RASM-5NE
14A/PH
20A-3PH
4mm² x 5*
27A/PH
30A-3PH
10mm² x 5*
RASM-6NE
16A/PH
32A-3PH
6mm² x 5*
29A/PH
40A-3PH
10mm² x 5*
*All Cable and Breaker sizes should be checked by a NICEIC qualified Electrician

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Control Wiring
This shows a basic heating and domestic hot water system as shown on the first page.
Connections are made onto the main terminal block in the monobloc unit.
Please Note
• Be sure to run the PC-ARFHE Controller cable and tank sensor cables separately to all of
the other cables to avoid electrical interference with the control circuit
• We recommend taking the immersion heater and the heating pump wiring through local
fused switches mounted next to each (Pump—5A and Heater 16A)
• The tank hot water sensor is a Hitachi specific part and not a generic item.
• Please confirm all details with the relevant Hitachi installation manuals.
• All electrical wiring must be carried out by a competent electrician in accordance with
local and national regulations.
• Make sure the immersion heater thermostat is set to maximum
Dip Switch Settings—DSW4
Modify DSW4 with the power turned off
Dip Switch 4—Turn pin 3 ON to enable the immersion heater
Dip Switch 4—Turn pin 5 ON to enable ECO Pump mode
Dip Switch 4—Turn pin 6 ON to enable antifreeze mode
Dip Switch 4—Turn pin 8 ON to enable DHW Defrost if desired
DHW Defrost is an optional feature that switches to DHW mode during defrost cycles to pro-
tect the heat exchanger against freezing when using a low loss header instead of a buffer
tank
Earth
Earth
Earth
N L
E N L
Open N E
Open N E
Ensure it can switch
at least 5A at 220V
Thermostat
Base Station
Link terminal L to
COM. Switched
feed is terminal NO
NC
NO
COM
3 Port Diverting Valve
Motor Open for Tank Mode
Terminals 32 & 34
Immersion Heater 3KW—220V
Terminals 30 & 31
Hitachi PC-ARFHE
Terminals 3 & 4
Heating Control
Base Station
Terminals 13, 14
and 34
Tank Hot Water Sensor
Terminals 5 & 6
Heating Circulation Pump and Zone Valve
Fed from Heating Controller

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Pre-Start Checks
Please check the following before commencing startup.
• Power must be supplied to the monobloc unit for at least 8 hours before start up in or-
der to provide sufficient power to the compressor heater
• Check all electrical wiring and connections
• Make sure all auto air vents are open and the pressure relief valves are closed
• Make sure the system is filled with the correct coolant fluid to around 2 Bar
• Check the expansion vessel is large enough. The Yutaki M unit contains a 6 litre expan-
sion tank large enough for 150 litres. For larger water volumes or more than 8m
height difference then an extra expansion vessel is required.
• Check all fuses and circuit breakers.
Controller Setup on Start Up
Once you have selected Configuration Assistant Answer the questions -
• Is this device attached to the unit—YES
• Is this device controlling the unit—YES
• Is this device used as the room thermostat of a zone—NO
• How many circuits do you have—ONE
• What are the heat emitters installed on circuit one—RADIATORS*
• Do you have a domestic hot water tank installed—YES
• Do you have a swimming pool installed—NO
• Do you have a boiler installed—NO
• Do you have an electric backup heater installed—NO
• How many thermostats are installed—NONE
As soon as you are set up as above enter Installer mode by pressing OK & Return
for 3 seconds and then entering the password right, down, left, right, enter.
The spanner icon should appear on the display. You are now ready for setup

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Getting Started
Once you have selected Installer Mode then you can negotiate the controller using the
various buttons and can return to the main screen at any time using the return button to get
back to the home screen.
Air Purge Mode
Before doing anything else make sure all of the water valves in the system are open, that
the system is maintaining pressure and the air vents are all open. Manually open the 3 way
valve. Now press MENU, select Commissioning OK, Select Air Purge Procedure OK, set a dura-
tion of 30 minutes then select Start Air Purge OK then select Yes OK to start the air purge
procedure.
Repeat if 30 minutes is not enough to remove all of the air in the system. Keep the pressure
topped up as air is purged from the system. You should be able to clearly hear the pump and
water circulation sound become quieter and more stable as air is removed.
The water flow rate will change constantly during the air purge mode. Do not pay too much
attention to it at this stage except to ensure that water is actually flowing.
Factory Reset
If you need to carry out the start up procedure again for any reason it is very easy to do a
factory reset. Enter installer mode as shown below. Then go into the main menu and scroll
down the options until you get to Factory Reset. Select this then Yes and OK.
Installer Mode
At any time you can enter Installer Mode which makes a lot of functions visible that were pre-
viously locked out. Press OK and Return for 3 seconds and enter the password Right, Down,
Left, Right, OK. A spanner appears on the display right bottom in Installer Mode.
Return to User Mode
If you are in Installer Mode with the spanner showing and you want to go back into user mode
then you have two options. The first is to leave things alone and the Installer Mode willtime
out of its own accord. The second is to go into the Main Menu, scroll all the way down toReturn
to User Mode , select then Yes and OK.

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Setting the Space Heating Mode
To set the water temperature in space heating mode you have two options, to set a constant
water temperature or to set a weather compensated heat curve. We normally suggest a heat
curve is best for most applications and this is the method we shall describe here. See the
suggested settings below.
In installer mode press the MENU button and then select SYSTEM CONFIGURATION and then
SPACE HEATING and CIRCUIT 1
Select WATER CALCULATION MODE and choose POINTS
Use the right and left keys to navigate between the four points on the graph and the up and
down keys to change the value of each point. When setting up and testing the unit choose
55, 50, -5 and 15 but for normal operation see the notes below.
Weather compensation settings
Testing the unit 55, 50, -5, 15
Underfloor Heating 35, 30, -5, 15
Modern Radiators 45, 35, -5, 15
Old Fashioned Radiators 52, 40, -5, 15
Setting the Domestic Hot Water Settings
You have a choice to make here. To optimise the hot water tank to prevent the growth of
legionella or to optimise for scald prevention and economy.
Please discuss this with the end user and leave the choice up to them, unless you do not
have an immersion heater fitted (or it is controlled by an immersun or external thermo-
stat) in which case you will not be able to optimise for legionella.
The Issues
Legionella bacteria can grow in water tanks between 20C and 45C. Above this tempera-
ture the bacteria will be killed. Some authorities believe that a weekly legionella cycle is
required to ensure all bacteria is killed off. In order to catch Legionnaires disease contami-
nated water must first be vaporised and then breathed in.
If legionella is to be killed using a legionella cycle then the water temperature must be in-
creased to, usually, 60C. The problem with this is that the time taken for a scald to de-
velop at 50C is measured in minutes but at 60C it is in seconds. In addition this cannot
normally be done by the heat pump without assistance from an electric immersion heater.
Continued on next page

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Optimisation for scald protection entails setting the hot water temperature in the cylinder
at 50C which can be carried out by the heat pump in most circumstances. This avoids sys-
tematic use of the immersion heater and taking the hot water to a temperature which risks
scalds. If you choose this option then the tank temperature should be set at 50C to avoid le-
gionella growth.
In installer mode press the MENU button and then select SYSTEM CONFIGURATION and then
DHW
Set the settings up as follows
Status Enabled
Control High Efficiency
Maximum Setting T 52C
Differential Temp 6C
HP OFF differential T 5C
HP ON differential T 10C
Maximum Time 40 mins
Cycle Time 1 hour
El. Heater Wait Time 20 mins
Space Priority Status Disabled
Anti Legionella Disabled
Optimisation for Legionella protection allows the hot water temperature to be set lower
than 50C normally but a weekly boost cycle will heat the cylinder to 60C to kill off any bacte-
ria. This requires the Yutaki unit to control an immersion heater in the cylinder.
If you choose this option then the tank temperature can be set between 45C & 50C
In installer mode press the MENU button and then select SYSTEM CONFIGURATION and then
DHW
Set the settings up as above except for the Anti Legionella setting. Set this up as
Status Enabled
Operation Day Discuss with customer
Starting Time Discuss with customer
Setting Temperature 60C
Duration 10 minutes
If your customer has Solar PV then it may be good to select a legionella cycle during daylight
hours. If not then it is probably best to select a time when the hot water is unlikely to be
used. As standard this is set for Sunday at 1am.
Make sure at this point—
1. That the immersion heater is connected to the Yutaki unit terminals 30 & 31
2. That the immersion heater is enabled—Dip switch 4 pin 3 is ON
3. That the internal thermostat in the immersion heater is set to maximum
Weekly
60C
Boost
from
45C
Tries to
maintain
50C all of
the time

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Your details
After setting the heat pump up then the final task before testing the heat pump is to enter
your details so the customer can contact you if there is a problem.
In Installer Mode go back to the Main Menu, scroll down to ABOUT then select CONTACT
INFORMATION. You can then enter your name and phone number one character at a time.
Enter your
details
Your system is now Fully Set up and Ready for Test Run
Before Test Run please ensure that
1. Power has been ON to the outdoor unit for at least 8 hours
2. All shut off valves are open. Including the ones you had forgotten about!
3. All auto air vents are open and the three port valve is in auto mode
4. The room thermostat is switched OFF
Important Note—Using a Hitachi Thermostat, wired or wireless
This manual is based around the use of a third party RF programmable controller NOT a Hi-
tachi wired or wireless controller. If you are going to use a Hitachi controller then please con-
tact Secon Solar Technical as the wiring schematic and setup procedure are different to that
shown in this manual.
Important Note—Using a Mirror Box
If you are using a mirror box please contact Secon Renewable
Technical
We have an additional manual for use with this item

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System Test
Assuming you have set up the system as recommended then you are ready to do a run test
of the system.
Controller Description
Simple Tasks
1. LCD Display—See below for more details
2. OK—to select and confirm selection
3. Arrows Key—to navigate menus and selections
4. On / Off button and Run / Trip Light
5. Menu Button
6. Return Button
7. Favourite Button
System is Off or (no display) there is no power
System is On
System is in Fault Mode. Write Fault Code down
1. Time and Date
2. Operation Mode (sun icon shows heating)
3. Control of Heating Circuit showing the current set
temperature and other information
4. Control of Domestic Hot Water showing the current
set temperature and other information
5. Only used for Swimming Pool applications
6. Current Unit Status—in this case showing the pump
and compressor icons
7. Outdoor Temperature (normally) or Alarm Code
8. Which buttons are available currently? Spanner icon
appears if you are in Installer Mode.
• To set the room temperature—use the wireless RF thermostat
• To set the tank temperature use the arrow keys to highlight the DHW segment and change the setting
• To turn just heating mode on. Use the arrow keys to highlight the C1 display segment then press the On/
Off key so that the green light is shown. Press again to turn off.
• To turn just hot water mode on. Use the arrow keys to highlight the DHW display segment then press the
On/Off key so that the green light is shown. Press again to turn off.
• To turn both heating and hot water on. Use the On/Off key with no display segments selected. Press
again to turn off.
Installer Mode—to view relevant information
In installer mode with the unit running press the
MENU button, select OPERATION INFORMATION,
then select GENERAL. This will show the current
mode and relevant temperatures
Go back and Select HEAT PUMP DETAILS to see
more detailed information including water flow rate
Important—Water Flow
If alarm 70 or P70 shows then the unit water flow is
too low. Water flow levels are shown below and can be
checked using HEAT PUMP DETAILS see left.
Model
RASM-2
RASM-3
RASM-4
RASM-5
RASM-6
Minimum to run Maximum Flow
8.4 l/m (0.5m³hr) 31.7 l/min (1.9m³hr)
10.0 l/m (0.6m³hr) 35 l/min (2.1m³hr)
16.7 l/m (1.0m³hr) 46.7 l/min (2.8m³hr)
18.4 l/m (1.1m³hr) 50 l/min (3m³hr)
20.0 l/m (1.2m³hr) 50 l/min (3m³hr)

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System Test—Heating Mode
First ensure that the base station for the heating system is not sending a demand for heating.
Some systems let you do this on the base station and some need the thermostat to be turned
right down. Make sure you are in Installer Mode too before starting.
Once this is done press the left right icons and select the C1 segment of the display (3). Now
press the ON / OFF button, which should light up green.
Select me using the arrow keys
Press Me
I should turn green
If I turn red then there is a problem!
Now send a signal from the thermostat base station to the heat pump to run. The pump icon should now show
followed by the compressor logo. This may take some minutes. Be patient.
Once the pump logo has come on check the pump water flow using the instructions and table on page 9. If you
are low on water flow then cease testing and investigate. If not carry on.
After the compressor logo has come on then go outside and check that the outdoor fans are working, the com-
pressor is running and there is nothing untoward happening.
After twenty minutes to half an hour use the MENU key to go into the main menu, select OPERATION INFORMA-
TION and GENERAL. This will show you the flow and return temperature. Check that the flow temperature is
higher than the return by around 4 to 6C. Take note of these temperatures as well as the Water Setting and
Outdoor Ambient temperatures.
Now go back to OPERATION INFORMATION and select HEAT PUMP DETAILS. Check the water flow rate is still
correct and note down the other operating conditions as below
• Water Inlet and Outlet
• Water Outlet PHEX
• Water Flow rate and pump speed
• Outdoor Ambient Temperature
• R410a temperatures and pressures
• Expansion Valve %
• Inverter Operating Frequency
• Compressor Current
While you have the system in heating mode then this is a good time to bleed any radiators and ensure that any
part of the heating system you are responsible for is working correctly.
Once you have taken note of everything and can confirm that everything is working fine in heating mode then
turn the room thermostat (or base station) OFF and confirm that this stops the heat pump.
Once this is confirmed then use the ON/OFF switch to turn the heat pump off again so the green light goes out.
Key points to take care of
Have I got good water flow?
Am I getting 4 to 6C temp diff?
Is the water getting hot and going to the
right place?
Does everything sound and feel right?

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System Test—Tank Mode
Once you confirm the heat pump works correctly in heating mode then it is time to check the
operation in Tank mode.
Use the left and right arrows to highlight the DHW segment of the display then turn the heat
pump on using the ON/OFF switch
Select me using the arrow keys
Press Me
I should turn green
If I turn red then there is a problem!
Assuming the tank is starting from cold then the heat pump should start fairly soon. If you are not starting from
cold then check the tank is not too warm (from, say, prior immersion heater operation) for the heat pump to
start. You may have to let a lot of water out of the cylinder if this is the case. Eventually the pump and compres-
sor logos will come on. This may take some minutes. Be patient.
Once the pump logo has come on check the pump water flow using the instructions and table on page 9. If you
are low on water flow then cease testing and investigate. If not carry on.
After the compressor logo has come on then go outside and check that the outdoor fans are working, the com-
pressor is running and there is nothing untoward happening. Check the 3 port valve has opened too.
After twenty minutes to half an hour use the MENU key to go into the main menu, select OPERATION INFORMA-
TION and GENERAL. This will show you the flow and return temperature. Check that the flow temperature is
higher than the return by around 4 to 6C. Take note of these temperatures as well as the Water Setting and
Outdoor Ambient temperatures.
Now go back to OPERATION INFORMATION and select DHW. Note down the various readings.
Now go back to OPERATION INFORMATION and select HEAT PUMP DETAILS. Check the water flow rate is still
correct and note down the other operating conditions as below
• Water Inlet and Outlet
• Water Outlet PHEX
• Water Flow rate and pump speed
• Outdoor Ambient Temperature
• R410a temperatures and pressures
• Expansion Valve %
• Inverter Operating Frequency
• Compressor Current
Please note that if you have used the setup settings in this book then the immersion heater will be used, after
20 minutes, to assist the heat pump. Check that this is working correctly.
Once you have taken note of everything and can confirm that everything is working fine in hot water mode then
use the ON/OFF switch to turn the heat pump off again so the green light goes out.
Key points to take care of
Have I got good water flow?
Am I getting 4 to 6C temp diff?
Is the water getting hot and going to the
cylinder not buffer tank
Does everything sound and feel right?

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Check list after testing
Once the system has been fully tested in both heating and tank modes then it can be set up
to actually run for the customer. The end user should be dissuaded from trying to use the Hi-
tachi Yutaki controller themselves as they may not understand the ramifications of changes
they make. They should be, instead, thoroughly familiarised with the operation of the wireless
control thermostat which is what they will use to set the heating demand.
The important thing for them to know is what the green light is doing. If it is ON then the
heat pump is operating normally. If it is OFF then somebody has turned the heat pump off
and it needs to be turned on again or there is no LCD display then there is a problem and a
fuse has tripped or there is a power interruption. If it turns RED then the unit has a fault and
the unit will display a fault code which they should report to you.
So you should now turn the heat pump off on the controller so the green light is off then go
back into the Menu of the controller and do set up the following.
Go into Installer mode. Now select SYSTEM CONFIGURATION then SPACE HEATING then
CIRCUIT 1 and choose WATER CALCULATION MODE then POINTS
You should have set this up for testing but this is now finished.
When testing is finished we recommend changing this to
Underfloor Heating 35, 30, -5, 15
Modern Radiators 45, 35, -5, 15
Old Fashioned Radiators 52, 40, -5, 15
Now go back out of the menus and turn the heat pump back on without selecting either C1 or
DHW modes first so the heat pump works with both. You can now hand over the system to
the end user.
ALARM CODES
A red light means a fault and will be combined with an alarm code, as below. Pages 14 & 15
list these codes.

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