Mitsubishi Electric EHSC-VM6A User manual

SERVICE MANUAL
HYDROBOX
No. OCH503
CONTENTS
1. REFERENCE MANUAL................................... 2
2. SAFETY PRECAUTION................................... 3
3. SPECIFICATIONS............................................ 7
4. PART NAMES AND FUNCTIONS .................. 8
5. OUTLINES AND DIMENSIONS..................... 10
6. WIRING DIAGRAM........................................ 12
7. FIELD WIRING............................................... 16
8. WATER SYSTEM DIAGRAM......................... 20
9. CONTROLS ................................................... 21
10. TROUBLESHOOTING................................... 36
11. DISASSEMBLY PROCEDURE...................... 49
12. SUPPLEMENTARY INFORMATION ............. 63
13. SERVICE AND MAINTENANCE ................... 64
July 2011
Note:
•This manual describes only
service data of Hydrobox.
•RoHS compliant products have
<G> mark on the spec name
plate.
R410A
MAIN CONTROLLER
PARTS CATALOG (OCB503)
[Model name]
EHSC-VM6A
EHSC-YM9A
EHPX-VM2A
[Service Ref.]
EHSC-VM6A.UK
EHSC-YM9A.UK
EHPX-VM2A.UK
HYDROBOX
TENTATIVE

2
REFERENCE MANUAL
1
OUTDOOR UNIT'S SERVICE MANUAL
Service Ref. Service Manual No.
PUHZ-RP35/50/60/71VHA4
OCH451PUHZ-RP100/125/140VKA
PUHZ-RP100/125/140YKA
PUHZ-HRP71/100VHA
OCH425
PUHZ-HRP71/100VHA2
PUHZ-HRP71/100VHA2R1
PUHZ-HRP100VHA2R2
PUHZ-HRP100/125YHA
PUHZ-HRP100/125YHA2
PUHZ-HRP100/125YHA2R1
PUHZ-W50/85VHA
OCH439
PUHZ-W50/85VHA-BS
PUHZ-W85VHAR1
PUHZ-W85VHAR1-BS
PUHZ-W85VHA2.UK OCH465
PUHZ-W85VHA2-BS.UK
PUHZ-HW112/140YHA
OCH439
PUHZ-HW112/140YHA-BS
PUHZ-HW112/140YHA2
PUHZ-HW112/140YHA2-BS
PUHZ-HW140VHA
PUHZ-HW140VHA-BS
PUHZ-HW140VHA2
PUHZ-HW140VHA2(R1)-BS

3
SAFETY PRECAUTION
2
Please read the following safety precautions carefully.
WARNING:
Precautions that must be observed to prevent injuries or death.
CAUTION:
Precautions that must be observed to prevent damage to unit.
This installation manual along with the user manual should be left with the product after installation for future reference.
Mitsubishi Electric is not responsible for the failure of locally or field-supplied parts.
Be sure to perform periodical maintenance.
Be sure to follow your local regulations.
Be sure to follow the instructions provided in this manual.
•
•
•
WARNING
Mechanical
The hydrobox and outdoor units must not be installed, disassembled, relocated, altered or repaired by the user. Ask an authorised installer or technician. If the
unit is installed improperly or modified after installation by the user water leakage, electric shock or fire may result.
The outdoor unit should be securely fixed to a hard level surface capable of bearing its weight.
The hydrobox should be positioned on a hard vertical surface capable of supporting its filled weight to prevent excessive sound or vibration.
Do not position furniture or electrical appliances below the outdoor unit or hydrobox.
The discharge pipework from the emergency/safety devices of the hydrobox should be installed according to local law.
Only use accessories and replacement parts authorised by Mitsubishi Electric and employ a qualified technician to fit the parts.
Electrical
All electrical work should be performed by a qualified technician according to local regulations and the instructions given in this manual.
The units must be powered by a dedicated power supply and the correct voltage and circuit breakers must be used.
Wiring should be in accordance with national wiring regulations. Connections must be made securely and without tension on the terminals.
Earth unit correctly.
General
Keep children and pets away from both the hydrobox and outdoor units.
Do not use the hot water produced by the heat pump directly for drinking or cooking. This could cause illness to the user.
Do not stand on the units.
Do not touch switches with wet hands.
Annual maintenance checks on both the hydrobox and the outdoor unit should be done by qualified person.
Do not place items containing liquid in on top of the hydrobox. If they leak or spill onto the hydrobox damage to the unit and or fire could occur.
Do not place any heavy items on top of the hydrobox.
When installing or relocating, or servicing the hydrobox, use only the specified refrigerant (R410A) to charge the refrigerant lines. Do not mix it with any other
refrigerant and do not allow air to remain in the lines. If air is mixed with the refrigerant, then it can be the cause of abnormal high pressure in the refrigerant
line, and may result in an explosion and other hazards.
The use of any refrigerant other than that specified for the system will cause mechanical failure or system malfunction or unit breakdown. In the worst case, this
could lead to a serious impediment to securing product safety.
CAUTION
Use clean water that meets local quality standards on the primary circuit.
The outdoor unit should be installed in an area with sufficient airflow according to the diagrams in the outdoor unit installation manual.
The hydrobox should be located inside to minimise heat loss.
Water pipe-runs on the primary circuit between outdoor and indoor unit should be kept to a minimum to reduce heat loss.
Ensure condensate from outdoor unit is piped away from the base to avoid puddles of water.
Remove as much air as possible from water circuit.
Refrigerant leakage may cause suffocation. Provide ventilation in accordance with EN378-1.
Be sure to wrap insulation around the piping. Direct contact with the bare piping may result in burns or frostbite.
Never put batteries in your mouth for any reason to avoid accidental ingestion.
Battery ingestion may cause choking and/or poisoning.
Install the unit on a rigid structure to prevent excessive sound or vibration during operation.
If power to the hydrobox is to be turned off (or system switched off) for a long time, the water should be drained.
Preventative measures should be taken against water hammer, such as installing a Water Hammer Arrestor on the primary water circuit, as directed by the manu-
facturer.

4
CAUTION (SPLIT MODELS ONLY)
<Using R410A refrigerant heat pumps>
Use C1220 copper phosphorus, for copper and copper alloy seamless pipes, to connect the refrigerant pipes. Make sure the insides of the pipes are clean and
do not contain any harmful contaminants such as sulfuric compounds, oxidants, debris, or dust. Use pipes with the specified thickness. (Refer to 4.4.) Note the
following if reusing existing pipes that carried R22 refrigerant.
- Replace the existing flare nuts and flare the flared sections again.
- Do not use thin pipes. (Refer to 4.4.)
Store the pipes to be used during installation indoors and keep both ends of the pipes sealed until just before brazing. (Leave elbow joints, etc. in their packag-
ing.) If dust, debris, or moisture enters the refrigerant lines, oil deterioration or compressor breakdown may result.
Use ester oil, ether oil, alkylbenzene oil (small amount) as the refrigeration oil applied to the flared sections. If mineral oil is mixed in the refrigeration oil, oil dete-
rioration may result.
Do not use refrigerant other than R410A refrigerant. If another refrigerant is used, the chlorine will cause the oil to deteriorate.
Use the following tools specifically designed for use with R410A refrigerant. The following tools are necessary to use R410A refrigerant. Contact your nearest
dealer for any questions.
Tools (for R410A)
Gauge manifold Flare tool
Charge hose Size adjustment gauge
Gas leak detector Vacuum pump adapter
Torque wrench Electronic refrigerant charging scale
Be sure to use the correct tools. If dust, debris, or moisture enters the refrigerant lines, refrigeration oil deterioration may result.
Do not use a charging cylinder. If a charging cylinder is used, the composition of the refrigerant will change and system efficiency will be reduced.
WARNING (SPLIT MODELS ONLY)
Do not discharge refrigerant into the atmosphere if refrigerant leaks during installation, ventilate the room.
Use appropriate tools for high pressure refrigerant.
When pumping down refrigerant , stop the compressor before disconnecting the refrigerant pipes.
During installation securely fasten the refrigerant pipes before starting the compressor.
Check that refrigerant gas does not leak after the completion of installation.
Use R410A refrigerant only. Do not allow air to enter the lines. Failure to observe these instructions will cause mechanical failure, system failure or, in the worst
case, serious breach of product safety.

5
Cautions for units utilizing refrigerant R410A
CAUTIONS RELATED TO NEW REFRIGERANT
Use new refrigerant pipes.
If using the existing R22, be careful of the followings.
· For RP100, 125 and 140, be sure to perform replacement
operation before test run.
· Change flare nut to the one provided with this product.
Use a newly flared pipe.
· Avoid using thin pipes.
Charge refrigerant from liquid phase of gas
cylinder.
If the refrigerant is charged from gas phase, composition
change may occur in refrigerant and the efficiency will be
lowered.
Only use R410A refrigerant.
If other refrigerant (R22 etc.) is used, chlorine in refrige-
rant can cause deterioration of refrigerant oil etc.
Use a vacuum pump with a reverse flow check
valve.
Vacuum pump oil may flow back into refrigerant cycle and
that can cause deterioration of refrigerant oil etc.
Use the following tools specifically designed for
use with R410A refrigerant.
The following tools are necessary to use R410A refrigerant.
Handle tools with care.
If dirt, dust or moisture enters into refrigerant cycle, that can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
Do not use a charging cylinder.
If a charging cylinder is used, the composition of refrigera-
nt will change and the efficiency will be lowered.
Flare tool
Electronic refrigerant
charging scale
Vacuum pump adaptor
Size adjustment gauge
Gauge manifold
Torque wrench
Gas leak detector
Charge hose
Tools for R410A
Contamination inside refrigerant piping can cause deterio-
ration of refrigerant oil etc.
If dirt, dust or moisture enters into refrigerant cycle, it can
cause deterioration of refrigerant oil or malfunction of com-
pressor.
If large amounts of mineral oil enters, it can cause deterio-
ration of refrigerant oil etc.
The refrigerant oil applied to flare and flange
connections must be ester oil, ether oil or
alkylbenzene oil in a small amount.
Store the piping to be used indoors during
installation, and both ends of the piping sealed
until just before brazing. (Leave elbow joints, etc.
in their packaging.)
Ventilate the room if refrigerant leaks during
operation. If refrigerant comes into contact with
a flame, poisonous gases will be released.
Make sure that the inside and outside of refrige-
rant piping is clean and it has no contaminants
such as sulfur, oxides, dirt, shaving particles, etc,
which are hazard to refrigerant cycle.
In addition, use pipes with specified thickness.
Use the specified refrigerant only.
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the
unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the
spec labels provided with our products.
We will not be held responsible for mechanical failure,
system malfunction, unit breakdown or accidents caused
by failure to follow the instructions.

Gravimeter
Unit
6
[1] Cautions for service
(1) Perform service after recovering the refrigerant left in unit completely.
(2) Do not release refrigerant in the air.
(3) After completing service, charge the cycle with specified amount of refrigerant.
(4) When performing service, install a filter drier simultaneously.
Be sure to use a filter drier for new refrigerant.
[2] Additional refrigerant charge
When charging directly from cylinder
· Check that cylinder for R410A on the market is syphon type.
· Charging should be performed with the cylinder of syphon stood vertically. (Refrigerant is charged from liquid phase.)
[3] Service tools
Use the service tools below as exclusive tools for R410A refrigerant.
No. Tool name Specifications
1
Gauge manifold
· Only for R410A
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 5.3 MPa·G or over.
2
Charge hose · Only for R410A
· Use pressure performance of 5.09 MPa·G or over.
3Electronic scale —
4Gas leak detector · Use the detector for R134a, R407C or R410A
5Adaptor for reverse flow check · Attach on vacuum pump.
6Refrigerant charge base —
7
Refrigerant cylinder · Only for R410A ·Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —

7
SPECIFICATIONS
3
Model name EHSC-VM6A EHSC-YM9A EHPX-VM2A
Overall unit dimensions 800 × 530 × 360 mm (Height × Width × Depth)
Weight (empty) 54 kg 54 kg 39 kg
Weight (full) 60 kg 60 kg 44 kg
Plate heat exchanger
Unvented expansion vessel
(Primary circuit)
Nominal volume 10 L
Charge pressure 0.1 MPa (1 bar)
Safety device Water circuit
(Primary)
Control thermistor 1 - 80°C
Pressure relief valve 0.3 MPa (3 bar)
Flow switch Min flow 5.5 l/min
Booster heater Control thermistor 80°C
Manual reset thermostat 90°C
Thermal Cut Off (for dry run prevention) 121°C
Primary circuit circulating Pump Grundfos UPSO 25-70 180
Connections Water 28 mm compression primary circuit
Refrigerant
(R410A)
Liquid 9.52 mm 9.52 mm —
Gas 15.88 mm 15.88 mm —
Operating ambient condition 0 (*1) - 35°C ( 80 %RH)
Electrical data Control board Power supply
(Phase, voltage, frequency)
~/N, 230 V, 50 Hz
Breaker
(*when powered from
independent source)
10A
Booster heater Power supply
(Phase, voltage, frequency)
~/N, 230 V, 50 Hz 3~, 400 V, 50 Hz ~/N, 230 V, 50 Hz
Capacity 2 kW+4 kW 3 kW+6 kW 2 kW
Current 26 A 13 A 9 A
Breaker 32 A 16 A 16 A
*1 The environment must be frost-free.
Optional extras
• Wireless Remote Controller PAR-WT40R-E • Joint pipe (15.88 12.7) PAC-SH50RJ-E
• Wireless Receiver PAR-WR41R-E • Joint pipe (9.52 6.35) PAC-SH30RJ-E
• Remote sensor PAC-SE41TS-E

8
PART NAMES AND FUNCTIONS
4
Number Component
1 Control and electrical box
2 Main controller
3 Manometer
4 Expansion vessel
5 Expansion vessel charge valve
6 Automatic air vent
7 Booster heater
8 Drain cock
9 Water circulation pump
10 Pressure relief valve
11 Flow switch
12 Plate heat exchanger
13 Strainer valve
AInlet from space heating/Indirect DHW cylinder
(primary return)
BOutlet to space heating/Indirect DHW cylinder
(primary flow)
C Refrigerant (Liquid)
D Refrigerant (Gas)
EDischarge from pressure relief valve (installer to
pipe connect to suitable drain point)
1
2
3
4
6
5
7
8
9
11
10
12
13
ABCD
E
<EHSC> (Split model system)
Figure 4-1
Figure 4-2

9
Figure 4-3
Figure 4-4
Number Component
1 Control and electrical box
2 Main controller
3 Manometer
4 Expansion vessel
5 Expansion vessel charge valve
6
Automatic air vent
7 Booster heater
8 Drain cock
9 Water circulation pump
10 Pressure relief valve
11 Flow switch
13 Strainer valve
AInlet from space heating/Indirect DHW cylinder
(primary return)
B Inlet from heat pump
C Outlet to heat pump
DOutlet to space heating/Indirect DHW cylinder (pri-
mary flow)
EDischarge from pressure relief valve (installer to
pipe connect to suitable drain point)
1
2
3
7
8
9
10
11
13
ABCD
E
<EHPX> (Packaged model system)
4
6
5

48
357
348
381
237
326
142
96
189
86
124
163
461
233
253
282
55.5
(233)
590
520
264.5
800
110±5
100±5
56
77
142
189
233
253
282
48
89
86
124
157
163
237
461
348
357
520
800
264.5
577
110±5
55.5
(233)
10
OUTLINES AND DIMENSIONS
5
5-1. Technical Drawings (Unit: mm)
Letter Pipe description Connection size/type
ASpace heating/Indirect DHW cylinder (pri-
mary) return connection 28 mm/Compression
BSpace heating/Indirect DHW cylinder (pri-
mary) flow connection 28 mm/Compression
C Refrigerant (Liquid) 9.52 mm/Flare
D Refrigerant (Gas) 15.88 mm/Flare
EDischarge pipe (by installer) from pressure
relief valve
G1/2” female (valve port
within hydrobox casing)
F Electrical cable inlets
—
*The leftmost inlet is for
wireless receiver (option)
Letter Pipe description Connection size/type
ASpace heating/Indirect DHW cylinder (pri-
mary) return connection 28 mm/Compression
B Flow connection from heat pump 28 mm/Compression
C Return connection to heat pump 28 mm/Compression
DSpace heating/Indirect DHW cylinder (pri-
mary) flow connection 28 mm/Compression
EDischarge pipe (by installer) from pressure
relief valve
G1/2” female (valve port
within hydrobox casing)
F Electrical cable inlets
—
*The leftmost inlet is for wire-
less receiver (option)
F
A
BC
D
E
F
A
BC
D
E
<EHSC> (Split model system)
<EHPX> (Packaged model system)
<Front> <Side> <Rear>
<View from below>
<Front> <Side> <Rear>
<View from below>

a
bb
d
c
11
Service access
5-2. Service access diagrams
Service access
Parameter Dimension (mm)
a 200
b 150
c 500
d 500
Sufficient space MUST be left for the provision of discharge pipework as
detailed in National and Local building regulations.
The hydrobox must be located indoors and in a frost-free environment,
for example in a utility room.

* See Chapter 6-4.
12
6WIRING DIAGRAM
6-1. EHSC-VM6A

* See Chapter 6-4.
13
6-2. EHSC-YM9A

* See Chapter 6-4.
14
6-3. EHPX-VM2A

15
Automatic switch to backup heater only operation
Back-up heater operation (*1) will automatically run when the indoor unit stops abnormally.
To enable the function, switch Dip SW 2-5 to ON.
During the back-up operation, an error code(s) and the contact number will be displayed alternately.
External output (OUT11) will be available.
To clear the fault(s), reset the power breakers on the indoor and outdoor units.
<Applicable error codes (*2)>
E6 to E9, Ed, P8, U1 to U8, Ud, UE, UF, UL, UP
(*1) Prolonged running of the back-up operation may affect the life of the heater.
(*2) For safety reasons, this function is not available for certain faults. (System operation must be stopped and only pump keeps running.)
6-4. Dip switch setting
<Dip Switch Functions>
Located on the FTC3 printed circuit board are 4 sets of small white switches
known as Dip switches. The Dip switch number is printed on the circuit board
next to the relevant switches. The word ON is printed on the circuit board and on
the Dip switch block itself. To move the switch you will need to use a pin or the
corner of a thin metal ruler or similar.
Dip switch settings are listed below in the table below.
SW1 SW2
SW3
SW4
Dip switch Function OFF ON Default
(Indoor unit Ref.)
SW1 SW1-1 — — — OFF
SW1-2 Heat pump maximum outlet water
temperature
55 °C 60 °C OFF: EHSC ( 1)
ON : EHPX
SW1-3 DHW tank WITHOUT DHW tank WITH DHW tank OFF
SW1-4 Immersion heater WITHOUT immersion heater WITH immersion heater OFF
SW1-5 Booster heater WITHOUT booster heater WITH booster heater ON
SW1-6 Booster heater function For heating only For heating and DHW OFF
SW1-7 Outdoor unit type Split type Packaged type OFF: EHSC
ON : EHPX
SW1-8 Wireless remote controller
WITHOUT wireless remote controller WITH wireless remote controller OFF
SW2 SW2-1 Room thermostat input (IN1) logic change Operation stop at thermostat short Operation stop at thermostat open OFF
SW2-2 Flow switch input (IN2) logic change Failure detection at short Failure detection at open ON
SW2-3 Booster heater capacity restriction Inactive Active OFF: EHSC
ON : EHPX-VM2A
SW2-4 — — — OFF
SW2-5 Automatic switch to backup heater only op-
eration (When outdoor unit stops by error)
Inactive Active ( 3) OFF
SW2-6 — — — OFF
SW2-7 — — — OFF
SW2-8 — — — OFF
SW3 SW3-1 — — — OFF
SW3-2 — — — OFF
SW3-3 — — — OFF
SW3-4~8 — — — OFF
SW4 SW4-1~4 — — — OFF
SW4-5 Emergency mode (Heater only operation) Normal Emergency mode (Heater only operation)
(To be activated only when powered ON)
OFF ( 2)
SW4-6 — — — OFF
Notes:
1. For packaged model system, the max outlet water temperature is always 60°C so default Dip switch SW1-2 is ON.
For split model system, the max outlet water temperature is usually 55°C except in the case of PUHZ-HRP outdoor model where the max
outlet water temperature is 60°C and DIP switch SW1-2 should be changed to ON.
2.
If emergency mode is no longer required, please turn off both outdoor and indoor unit power supply before returning SW4-5 to OFF position.
3. For safety reasons, this function is not available for certain errors. (System operation must be stopped and only pump keeps running.)
External output (OUT11) will be available.

Power
supply
~/N
230V
50Hz
Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
L
N
S1
S2
S3
Outdoor unit
S1
S2
S3
TB1
L
N
ECB1
Wiring
circuit
breaker
or
Isolating
switch
To control
board
ELB for
booster
heater
(Primary circuit)
Power
supply
~/N
230V
50Hz
Hydrobox
L
N
16
FIELD WIRING
7
Option 1: Hydrobox powered via outdoor unit
<1 phase>
<Figure 7-1>
Electrical connections 1 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW (EHPX-VM2A) 16 A *1 2.5 mm²
6 kW (EHSC-VM6A) 32 A *1 6.0 mm²
Wiring
Wiring No.
× size (mm²)
Hydrobox - Outdoor unit *2 3 × 1.5 (polar)
Hydrobox - Outdoor unit earth *2 1 × Min. 1.5
Circuit
rating
Hydrobox - Outdoor unit S1 - S2 *3 AC230V
Hydrobox - Outdoor unit S2 - S3 *3 DC24V
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.
*2. Max. 45 m
If 2.5 mm² used, Max. 50 m
If 2.5 mm² used and S3 separated, Max. 80 m
*3. The values given in the table above are not always measured against the ground value.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Indoor unit/outdoor unit connecting cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60245 IEC 57)
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60227 IEC 53)
3. Install an earth longer than other cables.
4. The power supply MUST have sufficient capacity for each heater and ALL electrical loads. Insufficient power supply may result in
chattering of load contactor(s).
* Installer MUST affix label A that is included with the manuals near each wiring diagram for hydrobox and outdoor units.

Power
supply
3N~
400V
50Hz
Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
L1
L2
S1
S2
S3
Outdoor unit
S1
S2
S3
TB1
L2
L3
ECB1
Wiring
circuit
breaker
or
Isolating
switch
To control
board
ELB for
booster
heater
(Primary circuit)
Power
supply
3~
400V
50Hz
N
L3
L1
Hydrobox
L2
L1
17
<3 phase>
<Figure 7-2>
Electrical connections 3 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400V 50Hz 9 kW (EHSC-YM9A) 16 A *1 2.5 mm²
Wiring
Wiring No.
× size (mm²)
Hydrobox - Outdoor unit *2 3 × 1.5 (polar)
Hydrobox - Outdoor unit earth *2 1 × Min. 1.5
Circuit
rating
Hydrobox - Outdoor unit S1 - S2 *3 AC230V
Hydrobox - Outdoor unit S2 - S3 *3 DC24V
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.
*2. Max. 45 m
If 2.5 mm² used, Max. 50 m
If 2.5 mm² used and S3 separated, Max. 80 m
*3. The values given in the table above are not always measured against the ground value.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Indoor unit/outdoor unit connecting cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60245 IEC 57)
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60227 IEC 53)
3. Install an earth longer than other cables.
4. The power supply MUST have sufficient capacity for each heater and ALL electrical loads. Insufficient power supply may result in
chattering of load contactor(s).
* Installer MUST affix label A that is included with the manuals near each wiring diagram for hydrobox and outdoor units.

S1
S2
S3
L
N
L
N
BLACK BLACK
YELLOW YELLOW YELLOW
YELLOW
BLACK
BLACK
CNO1
CNO1
CNO1
Black
CNO1
Black
Hydrobox
control board
Hydrobox
control board
S1
S2
S3
Initial settings
(Power supplied
by outdoor unit)
Modified settings
(Separate power
supply to
the hydrobox)
Power
supply
~/N
230V
50Hz
Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
L
N
S1
S2
S3
Outdoor unit
S1
S2
S3
TB1
L
N
ECB1
Wiring
circuit
breaker
or
Isolating
switch
To control
board
ELB for
booster
heater
(Primary circuit)
L
N
Power
supply
~/N
230V
50Hz
Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
~/N
230V
50Hz
Hydrobox
18
Option2: Hydrobox powered by independent source.
If the hydrobox and outdoor units have separate power supplies, the following
requirements MUST be carried out:
• Hydrobox electrical box connector connections changed (see Figure
4.5.6)
• Outdoor unit DIP switch settings changed to SW8-3 ON.
• Turn on the outdoor unit BEFORE the hydrobox.
<1 phase>
<Figure 7-4>
Electrical connections 1 phase
<Figure 7-3>
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW (EHPX-VM2A) 16 A *1 2.5 mm²
6 kW (EHSC-VM6A) 32 A *1 6.0 mm²
Hydrobox power supply ~/N 230 V 50 Hz
Hydrobox input capacity
Main switch (Breaker)
*1 16 A
Wiring
Wiring No.
× size (mm²)
Hydrobox power supply 2 × Min. 1.5
Hydrobox power supply earth 1 × Min. 1.5
Hydrobox - Outdoor unit *2 2 × Min. 0.3
Hydrobox - Outdoor unit earth —
Circuit
rating
Hydrobox L - N *3 AC230V
Hydrobox - Outdoor unit S1 - S2 *3 —
Hydrobox - Outdoor unit S2 - S3 *3 DC24V
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.
*2. Max. 120 m
*3. The values given in the table above are not always measured against the ground value.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Indoor unit/outdoor unit connecting cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60245 IEC 57)
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60227 IEC 53)
3. Install an earth longer than other cables.
4. The power supply MUST have sufficient capacity for each heater and ALL electrical loads. Insufficient power supply may result in
chattering of load contactor(s).
* Installer MUST affix label B that is included with the manuals near each wiring diagram for hydrobox and outdoor units.

Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
L1
L2
S1
S2
S3
Outdoor unit
S1
S2
S3
TB1
L2
L3
ECB1
Wiring
circuit
breaker
or
Isolating
switch
To control
board
ELB for
booster
heater
(Primary circuit)
N
L3
L1
L
N
Earth
leakage
breaker
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
~/N
230V
50Hz
Power
supply
3N~
400V
50Hz
Power
supply
3~
400V
50Hz
Hydrobox
19
<3 phase>
<Figure 7-5>
Electrical connections 3 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400V 50Hz 9 kW (EHSC-YM9A) 16 A *1 2.5 mm²
Hydrobox power supply ~/N 230 V 50 Hz
Hydrobox input capacity
Main switch (Breaker)
*1 16 A
Wiring
Wiring No.
× size (mm²)
Hydrobox power supply 2 × Min. 1.5
Hydrobox power supply earth 1 × Min. 1.5
Hydrobox - Outdoor unit *2 2 × Min. 0.3
Hydrobox - Outdoor unit earth —
Circuit
rating
Hydrobox L - N *3 AC230V
Hydrobox - Outdoor unit S1 - S2 *3 —
Hydrobox - Outdoor unit S2 - S3 *3 DC24V
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
The breaker shall be provided to ensure disconnection of all active power (i.e. phase AND neutral) conductors of the supply.
*2. Max. 120 m
*3. The values given in the table above are not always measured against the ground value.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Indoor unit/outdoor unit connecting cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60245 IEC 57)
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60227 IEC 53)
3. Install an earth longer than other cables.
4. The power supply MUST have sufficient capacity for each heater and ALL electrical loads. Insufficient power supply may result in
chattering of load contactor(s).
* Installer MUST affix label B that is included with the manuals near each wiring diagram for hydrobox and outdoor units.

20
WATER SYSTEM DIAGRAM
8
EHSC-VM6A
EHSC-YM9A
EHPX-VM2A
1. Check all connections including factory fitted ones are tight.
2. Insulate pipe work between hydrobox and outdoor unit.
3. Thoroughly clean and flush, system of all debris. (see section 4.2 for detailed instructions.)
4. Fill primary heating circuit with water and suitable anti-freeze and inhibitor as necessary. Always use a filling loop with double check valve when filling the
primary circuit to avoid back flow contamination of water supply.
Anti-freeze should always be used for package systems. It is the responsibility of the installer to decide if anti-freeze solution should be used in split systems
depending on each site’s conditions. Corrosion inhibitor should be used in both split and package systems.
When connecting metal pipes of different materials insulate the joints to prevent a corrosive reaction taking place which will damage the pipework.
•
•
5. Check for leaks. If leaks are found, retighten the screws on the connections.
6. Pressurise system to 1 bar.
7. Release all trapped air using air vents during and following heating period.
8. Top up with water as necessary. (If pressure falls below 1 bar)
Filling the System (Primary Circuit)
Draining the Hydrobox
WARNING: DRAINED WATER MAY BE VERY HOT
1. Before attempting to drain the hydrobox islolate from the electrical supply to prevent booster heater burning out.
2. Isolate hydrobox from primary water circuit and drain water from hydrobox. Use a suitable heat resistant hose to assist in these operations.
3. Drain any remaining water from booster heater using fitted drain cock and hose, and the drain valve on the primary circuit to safely drain the unit.
4. After the hydrobox is drained, water remains in the following component parts. Drain water completely by checking the inside of the parts.
• Strainer (Remove the strainer cover.)
• Pressure relief valve (Operate the valve.)