Mitsubishi Electric EHST20C-VM2C.UK User manual

SERVICE MANUAL
CONTENTS
1. REFERENCE MANUAL................................... 2
2. SAFETY PRECAUTION................................... 3
3. SPECIFICATIONS............................................ 6
4. PART NAMES AND FUNCTIONS .................. 7
5. OUTLINES AND DIMENSIONS....................... 8
6. WIRING DIAGRAM........................................ 10
7. FIELD WIRING............................................... 17
8. WATER SYSTEM DIAGRAM......................... 21
9. CONTROLS ................................................... 25
10. TROUBLESHOOTING................................... 45
11. DISASSEMBLY PROCEDURE...................... 61
12. SUPPLEMENTARY INFORMATION ............. 84
13. SERVICE AND MAINTENANCE ................... 85
Note:
•This manual describes
only service data of cylin-
der unit.
•RoHS compliant products
have <G> mark on the
spec name plate.
R410A
PARTS CATALOG (OCB570)
CYLINDER UNIT
December 2014
CYLINDER UNIT
No. OCH570
[Model name]
EHST20C-VM2C
EHST20C-VM6C
EHST20C-YM9C
EHST20C-TM9C
EHST20C-VM2EC
EHST20C-VM6EC
EHST20C-YM9EC
EHST20C-MHCW
EHST20C-MEC
EHST20D-VM2C
EHST20D-MHCW
EHST20D-MEC
EHST20D-MHC
EHPT20X-VM2C
EHPT20X-VM6C
EHPT20X-YM9C
EHPT20X-TM9C
EHPT20X-MHCW
[Service Ref.]
EHST20C-VM2C.UK
EHST20C-VM6C.UK
EHST20C-YM9C.UK
EHST20C-TM9C.UK
EHST20C-VM2EC.UK
EHST20C-VM6EC.UK
EHST20C-YM9EC.UK
EHST20C-MHCW.UK
EHST20C-MEC.UK
EHST20D-VM2C.UK
EHST20D-MHCW.UK
EHST20D-MEC.UK
EHST20D-MHC.UK
EHPT20X-VM2C.UK
EHPT20X-VM6C.UK
EHPT20X-YM9C.UK
EHPT20X-TM9C.UK
EHPT20X-MHCW.UK
MAIN REMOTE
CONTROLLER

2
REFERENCE MANUAL
1
OUTDOOR UNIT'S SERVICE MANUAL
Service Ref. Service Manual No.
PUHZ-W50/85VHA(-BS)
OCH439
PUHZ-W50/85VHAR1(-BS)
PUHZ-W50VHAR2(-BS)
PUHZ-W50VHAR3(-BS)
PUHZ-W85VHA2-BS.UK OCH465
PUHZ-W85VHA2(R1)-BS.UK
PUHZ-W112VHA(-BS) OCH562
PUHZ-HW112/140YHA(-BS)
OCH439
PUHZ-HW112/140YHA2(-BS)
PUHZ-HW112/140YHA2R1(-BS)
PUHZ-HW112/140YHA2R3(-BS)
PUHZ-HW112/140YHA2R4(-BS)
PUHZ-HW140VHA(-BS)
PUHZ-HW140VHA2(-BS)
PUHZ-HW140VHA2R1(-BS)
PUHZ-HW140VHA2R2-BS
PUHZ-HW140VHA2R3(-BS)
PUHZ-HW140VHA2R4(-BS)
PUHZ-SW40/50VHA(-BS) OCH525
PUHZ-SW40/50VHAR1(-BS)
PUHZ-SW75/100/120VHA(-BS)
OCH533PUHZ-SW100/120YHA(-BS)
PUHZ-SW100/120YHAR1(-BS)
PUHZ-SHW80/112VHA
OCH526
PUHZ-SHW80/112VHAR2(-BS).UK
PUHZ-SWH112/140YHA(R1)
PUHZ-SWH112/140YHAR2(-BS).UK
PUHZ-FRP71VHA OCH544
SUHZ-SW45VA(H).TH OCH557
SUHZ-SW45VA(H)R1.TH
OCH570

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-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 cylinder unit and outdoor unit 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 modied after installation by the user water leakage, electric shock or re may result.
The outdoor unit should be securely xed to a hard level surface capable of bearing its weight.
The cylinder unit should be positioned on a hard level surface capable of supporting its lled weight to prevent excessive sound or vibration.
Do not position furniture or electrical appliances below the outdoor unit or cylinder unit.
The discharge pipework from the emergency devices of the cylinder unit should be installed according to local law.
Only use accessories and replacement parts authorised by Mitsubishi Electric ask a qualied technician to t the parts.
Electrical
All electrical work should be performed by a qualied 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 cylinder unit and outdoor unit.
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 cylinder unit and the outdoor unit should be conducted by a qualied person.
Do not place containers with liquids on top of the cylinder unit. If they leak or spill onto the cylinder unit damage to the unit and/or re could occur.
Do not place any heavy items on top of the cylinder unit.
When installing, relocating, or servicing the cylinder unit, use only the specied 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 specied 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.
In heating mode, to avoid the heat emitters being damaged by excessively hot water, set the target ow temperature to a minimum of 2ºC below the maximum
allowable temperature of all the heat emitters. For Zone2, set the target ow temperature to a minimum of 5ºC below the maximum allowable ow temperature
of all the heat emitters in Zone2 circuit.
CAUTION
Use clean water that meets local quality standards on the primary circuit.
The outdoor unit should be installed in an area with sufcient airow according to the diagrams in the outdoor unit installation manual.
The cylinder unit 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 the primary and DHW circuits.
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.
Do not transport the cylinder unit with water inside the DHW tank. This could cause damage to the unit.
If power to the cylinder unit is to be turned off (or system switched off) for a long time, the water should be drained.
If unused for a long period, before operation is resumed, DHW tank should be ushed through with potable water.
Preventative measures should be taken against water hammer, such as installing a Water Hammer Arrestor on the primary water circuit, as directed by the man-
ufacturer.
As for the handling of refrigerant, refer to the outdoor unit installation manual.
OCH570

4
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.
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 specied thickness. (Refer to section 4.4 in
the installation manual.) Note the following if reusing existing pipes that carried R22 refrigerant.
- Replace the existing are nuts and are the ared sections again.
- Do not use thin pipes. (Refer to section 4.4 in the installation manual.)
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 ared 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 specically 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, a cylindrical measuring container, when charging R410A refrigerant gas. If the refrigerant gas is transferred to a charging cylinder,
the composition of the refrigerant will change and system efciency will be reduced.
OCH570

Gravimeter
Unit
5
[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 refrigerant cylinder
· Check that cylinder for R410A on the market is syphon type.
· Charging should be performed with the refrigerant 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
1Gauge manifold
· Only for R410A
· Use the existing fitting specifications. (UNF1/2)
· Use high-tension side pressure of 5.3 MPa·G or over.
2Charge 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 —
7Refrigerant cylinder · Only for R410A ·Top of cylinder (Pink)
· Cylinder with syphon
8Refrigerant recovery equipment —
OCH570

6
SPECIFICATIONS
3
Model name
EHST20C- VM2C
EHST20C- VM6C
EHST20C- YM9C
EHST20C- TM9C
EHST20C- VM2EC
EHST20C- VM6EC
EHST20C- YM9EC
EHST20C- MEC
EHST20D- VM2C
EHST20D- MEC
EHST20D- MHC
EHPT20X- VM2C
EHPT20X- VM6C
EHPT20X- YM9C
EHPT20X- TM9C
EHPT20X- MHCW
EHST20C- MHCW
EHST20D- MHCW
Nominal domestic hot water volume 200L Overall unit dimensions 1600 × 595 × 680 mm (Height × Width × Depth) Weight (empty) 110 kg 111 kg 112 kg 112 kg 104 kg 105 kg 106 kg 103 kg 103 kg 96 kg 103 kg 98 kg 99 kg 100 kg 100 kg 98 kg 110 kg 103 kg
Weight (full) 320 kg 321 kg 322 kg 322 kg 314 kg 315 kg 316 kg 313 kg 312 kg 305 kg 312 kg 307 kg 308 kg 309 kg 309 kg 307 kg 320 kg 312 kg
Plate heat exchanger (MWA2) ———————— —
Plate heat exchanger (MWA1) ———————— ——————
Unvented expansion vessel(Primary heating)
Nominal volume 12 L — — -— — 12 L — 12 L
Charge pressure 1 bar — — — — 1 bar — 1 bar
Safety device
Water circuit
(Primary)
Control thermistor Heating 1 - 80°C Pressure relief valve 0.3 MPa (3bar) Flow sensor Min ow 5.0 L/min
Booster heater
Manual reset thermostat 90°C — 90°C — — 90°C — — —
Thermal Cut-out (for dry run prevention) 121°C — 121°C — — 121°C — — —
DHW tank
Control thermistor 40 - 70°C Temperature and pressure relief valve/ Pressure relief valve
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
90°C/
0.7 MPa
(7 bar)
90°C/
0.7 MPa
(7 bar)
90°C/
0.7 MPa
(7 bar)
Primary circuit circulating Pump Grundfos UPM2 15 70 - 130 Sanitary circuit circulating Pump Grundfos UPSO 15-60 130 CIL2 Connections
Water 28mm compression primary circuit/ 22mm compression DHW circuit
Refrigerant (R410A)
Liquid 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 6.35 mm 6.35 mm 6.35 mm —————9.52 mm 6.35 mm
Gas 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 12.7 mm 12.7 mm 12.7 mm 15.88 mm 12.7 mm
Target tempera- ture range
Flow tem- perature
Heating 25 - 60°C Cooling —
Room tem- perature
Heating 10 - 30 °C Cooling —
Guaranteed operating range
Ambient *1 0 - 35°C ( 80 %RH)
Outdoor temperature
Heating See outdoor unit spec table. Cooling —
DHW tank performance
Maximum allowable hot water temperature
70°C *4 70°C *4 70°C
Time to raise DHW tank temp 15 - 65 °C *2
22.75 mins
Time to reheat 70% of DHW tank to 65 °C *2
17.17 mins
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
~/N, 230 V,
50 Hz
3~, 400 V,
50 Hz
3~, 230 V,
50 Hz
~/N, 230 V,
50 Hz
~/N, 230 V,
50 Hz
3~, 400 V,
50 Hz —~/N, 230 V,
50 Hz — — ~/N, 230 V,
50 Hz
~/N, 230 V,
50 Hz
3~, 400 V,
50 Hz
3~, 230 V,
50 Hz ———
Capacity 2kW 2kW+
4kW
3kW+
6kW
3kW+
6kW 2kW 2kW+
4kW
3kW+
6kW — 2kW — — 2kW 2kW+
4kW
3kW+
6kW
3kW+
6kW —
— —
Current 9 A 26 A 13A 23A 9 A 26 A 13A — 9 A — — 9 A 26 A 13A 23A —
— —
Breaker 16 A 32 A 16A 32A 16 A 32 A 16A — 16 A — — 16 A 32 A 16A 32A —
— —
Immersion heater*3
Power supply (Phase, voltage, frequency)
—~/N, 230 V,
50 Hz —~/N, 230 V,
50 Hz
Capacity — 3kW — 3kW Current — 13A — 13A Breaker — 16A — 16A
Sound level 28dBA
Optional extras
● Wireless Remote Controller PAR-WT50R-E ● Remote Sensor PAC-SE41TS-E *1 The environment must be frost-free. ● Wireless Receiver PAR-WR51R-E ● Thermistor PAC-TH011-E *2 Tested under BS7206 conditions. ● Immersion heater (1Ph 3kW) PAC-IH03V2-E ● High temperature thermistor PAC-TH011HT-E *3 Do not t immersion heaters without thermal cut-out. ● EHPT Accessories for UK PAC-WK01UK-E ● ecodan Wi-Fi Interface PAC-WF010-E *4 For the model without both booster heater and immersion heater, the maximum allowable hot water temperature is [Maximum outlet water of outdoor unit - 3°C]
For the maximum outlet water of outdoor unit, refer to outdoor unit data book.
OCH570

7
PART NAMES AND FUNCTIONS
4
21
B
A
<EH*T20*-MHCW>
(UK split / packaged model system)
7
4
12
<EHPT20X-*M**C*>
(Packaged model system)
<EHST20*-*M**C*>
(Split model system)
<EHST20*-*M**C>
(Split model system)
<Note>
For installation of EHST20*-*M*EC
model, make sure to install a primary -
side expansion vessel in the field. (See
figure 4.3.1 in the installation manual.)
No. Part name EHST20C-
VM2C
EHST20C-
*M6/9 C
EHST20C-
*M*EC
EHST20*-
MEC
EHST20D-
VM2C
EHST20D-
MHC
EHPT20X-
VM2C
EHPT20X-
*M6/9 C
EHPT20X-
MHCW
EHST20*-
MHCW
A DHW outlet pipe
BCold water inlet pipe
CWater pipe (Space heating return connection)
DWater pipe (Space heating ow connection)
EWater pipe (Flow from heat pump connection) —————— —
F Water pipe (Return to heat pump connection) — — — — — — —
GRefrigerant pipe (Gas) ———
HRefrigerant pipe (Liquid) ———
1Control and electrical box
2 Main controller
3Plate heat exchanger (Refrigerant - Water) ———
4 Booster heater 1,2 — — — —
53-way valve
6 Manual air vent
7 Drain cock (Primary circuit)
8 Manometer
9 Pressure relief valve (3bar)
10 Automatic air vent
11 Expansion vessel — —
12 Flow sensor
13 Strainer valve
14 Water circulation pump 1 (Primary circuit)
15 Pump valve
16 DHW tank
17 Plate heat exchanger (Water - Water)
18 Scale trap
19 Water circulation pump (Sanitary circuit)
20 Immersion heater — — — — — — —
21 Temperature and pressure relief valve — — — — — — — —
22 Pressure relief valve (10bar) (DHW Tank) — —
23 Drain cock (DHW tank)
24 Drain cock (Sanitary circuit)
25 Flow water temp. thermistor (THW1)
26 Return water temp. thermistor (THW2)
27 DHW tank water temp. thermistor (THW5)
28 Refrigerant liquid temp. thermistor (TH2) ———
29 Outdoor unit — — — — — — — — — —
30 Drain pipe (Local supply) — — — — — — — — — —
31 Back ow prevention device (Local supply) ——————————
32 Isolating valve (Local supply) ——————————
33 Magnetic lter (Local supply) (Recommended) ——————————
34 Strainer (Local supply) — — — — — — — — — —
35 Inlet control group *1 ——————————
36
Filling loop (Ball valves, check valves and exible hose) *1 ——————————
37 Potable expansion vessel *1 ——————————
*1 Supplied with UK model ONLY. Please refer to PAC-WK01UK-E Installation Manual for more information on accessories.
<EH*T20*-MHCW>
(UK split/packaged model system)
<EHPT20X-*M**C*>
(Packaged model system)
22
A
B
10
9
11
1
5
6
19
18
12
20
23
17
24
7
15
D
8
2
16
4
13
3
14
C
E/H
F/G
<Table 4-1>
<Figure 4-1>
OCH570

8
OUTLINES AND DIMENSIONS
5
<Unit: mm>
J
A
C
D
B
F/G
E/H
470.7
510.7
0
67.8
522.3
462.3
402.3
342.3
88.3
0
46.7
136.7
114.2
91.7
69.2
042.1
552.7 470.7 0
G1/2
83 427
30413
118
680
CPF 15mm
595
100 ± 20
449
1600
595
1600
449
J
A
B
D
C
F/G
E/H
46.7
136.7
114.2
91.7
69.2
0
67.8
522.3
462.3
402.3
342.3
127.8
0
552.7 542 0
470.7
510.7
0
680
100 ± 20
120 ± 20
G1/2
G1/2
118
123
Letter Pipe description Connection size/type
A DHW outlet connection 22 mm/Compression
BCold water inlet connection 22 mm/Compression
CSpace heating return connection 28 mm/Compression
DSpace heating ow connection 28 mm/Compression
EFlow from heat pump connection (No plate heat exchanger) 28 mm/Compression
FReturn to heat pump connection (No plate heat exchanger) 28 mm/Compression
GRefrigerant (GAS)
(With plate heat exchanger)
12.7 mm/Flare (EHST20D-*)
15.88 mm/Flare (EHST20C-*)
HRefrigerant (LIQUID)
(With plate heat exchanger)
6.35 mm/Flare (EHST20D-*)
9.52 mm/Flare (EHST20C-*)
J
Electrical cable inlets For inlets , and , run low-voltage wires including external input wires and ther-
mistor wires. For inlets and , run high-voltage wires including power cable, indoor-
outdoor cable, and external output wires.
*For a wireless receiver (option) cable and ecodan Wi-Fi interface (option) cable, use inlet .
<Left side> <Front> <Right side>
<Top>
Air vent
Main controller
Pressure relief valve
(Primary circuit)
Terminal block
Front panel
Temperature and
pressure relief valve
and it's access plate
<EH*T20*-*M**C>
<EH*T20*-MHCW>
Pressure relief valve
(Sanitary circuit)
Pressure relief valve
(Primary circuit)
Main controller
Terminal block
<Left side> <Front>
<Right side>
<Top>
Air vent
Front panel
5-1. Technical Drawings
OCH570

9
a
b b
d
Service access
5-2. Service access diagrams
Service access
Parameter Dimension (mm)
a 300
b 150
c
(distance behind unit not visible
in the right gure)
10
d 500
Sufcient space MUST be left for the provision of discharge pipework as detailed
in National and Local Building Regulations.
The cylinder unit must be located indoors and in a frost-free environment, for
example in a utility room, to minimise heat loss from stored water.
OCH570

1
3
5
7
X6
X7
1
3
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
CN22
(BLU)
1
5
Close
Open
N
X15
X12
TBO.3
TBO.2
TBO.1
F1
F2
MXV
M
1 ~
MP2
MP1
M
1 ~
CNV1
(WHT)
X11
X10
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
7
8
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
TAB1
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
MP3
M
1 ~
IN8 IN9
IN10
TBI.3
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)(Option)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
3WV
M
1 ~
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
ECB2
1
2
4
6
CN01
(WHT)
WHT WHT
2 2
2
ECB1
L
(1)
N
(3)
BHCP
BLU
BLU
RED
WHT/No.2 WHT/No.1
RED
VLT VLT
GRY GRY
BHC1
BHT
642
531 A1
A2
BH1
BHF
24
Power supply
to Booster heater
642
531 A1
A2
CNBH
(WHT)
CNBHT
(BLK)
2
2
2CNBC
(GRY)
1
1
3
3
1
3
~/N 230V 50Hz
1
2
3
4
5
6
TBO.4
M
2WV2a
1
3
X9
X8
X13
CNIH
(ORN)
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
10
6WIRING DIAGRAM
1. Symbols used in wiring diagram are, : connector, : terminal
block.
2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,
3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service.
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal
Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related
parts may be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen
in the service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 —
Water circulation pump 3 output (Space heating for Zone2)
*1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
6-1. EHST20C-VM2C, EHST20C-VM2EC, EHST20D-VM2C, EHPT20X-VM2C
Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1
Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BHC1 Contactor for booster heater 1
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
OCH570

WHT WHT
2 2 2
2
ECB1
L
(1)
N
(3)
BHCP
BLU
BLU
BLU
REDRED
BLU/No.3
WHT/No.2 WHT/No.1
BLU/No.4
RED
VLT VLT
PNK
PNK
GRY GRY
BHC2
BHC1
BHT
642
531 A1
A2
642
531 A1
A2
BH1
BHF
BH2
24
Power supply
to Booster heater
642
531 A1
A2
CNBH
(WHT)
CNBHT
(BLK)
2
2
2
2CNBC
(GRY)
1
1
3
5
7
3
1
3
~/N 230V 50Hz
1
3
5
7
X6
X7
1
3
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
CN22
(BLU)
1
2
3
4
5
6
1
5
Close
Open
N
TBO.4
TBO.2
TBO.1
F1
F2
M
2WV2a
MXV
M
1 ~
MP2
MP1
M
1 ~
1
3
CNV1
(WHT)
X9
X8
X13
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
TAB1
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
CNIH
(ORN)
MP3
M
1 ~
IN8 IN9
IN10
TBI.3
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)(Option)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
3WV
M
1 ~
ECB2
1
2
4
6
CN01
(WHT)
Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
X15
X12
TBO.3
X11
X10
1
2
3
4
5
6
7
8
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
11
6-2. EHST20C-VM6C, EHST20C-VM6EC, EHPT20X-VM6C
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal
Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts
may be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in
the service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 — Water circulation pump 3 output (Space heating for Zone2) *1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
1. Symbols used in wiring diagram are, : connector, : terminal
block.
2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,
3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service. Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1
Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
OCH570

NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
1
2
3
4
5
6
1
3
5
7
1
5
Close
Open
N
X6
X15
X12
X7
TBO.4
TBO.3
TBO.2
TBO.1
F1
F2
M
2WV2a
MXV
M
1 ~
MP2
MP1
M
1 ~
1
3
1
3
CNV1
(WHT)
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
X11
X9
X8
X13
X10
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
7
8
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
CNIH
(ORN)
MP3
M
1 ~
2 2 2
L2
(3)
L1
(1) L3 (5)
BHCP
BLK
BLK
WHT
WHTWHT
BLK
REDRED
BLU/No.4
WHT/No.2 WHT/No.3 WHT/No.1
BLU/No.5 BLU/No.6
RED
VLT VLT
PNK
PNK
WHT WHT
GRY GRY
BHC2
BHC1
BHT
642
531 A1
A2
642
531 A1
A2
BH1
BHF
BH2
24 6
Power supply
to Booster heater
642
531 A1
A2
CNBH
(WHT)
CNBHT
(BLK)
2
2
2
2
2
CNBC
(GRY)
1
1
3
5
7
3
1
3
3~ 400V 50Hz
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)(Option)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
ECB1 ECB2
1
2
4
6
CN01
(WHT)
3WV
M
1 ~
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN22
(BLU)
TAB1
IN8 IN9
IN10
TBI.3
Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
12
6-3. EHST20C-YM9C, EHST20C-YM9EC, EHPT20X-YM9C
1. Symbols used in wiring diagram are, : connector, : terminal
block.
2. Indoor unit and outdoor unit connecting wires have polarities, make sure
to match terminal numbers (S1, S2, S3) for correct wirings,
3. Since the outdoor unit side electric wiring may change, be sure to check
the outdoor unit electric wiring diagram for service.
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal
Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts
may be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in
the service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 — Water circulation pump 3 output (Space heating for Zone2) *1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1
Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
OCH570

2 2 2
ECB1
L2
(3)
L1
(1) L3 (5)
BHCP
BLK
BLK
WHT
WHTWHT
BLK
REDRED
BLU/No.4
WHT/No.2 WHT/No.3 WHT/No.1
BLU/No.5 BLU/No.6
RED
VLT VLT
PNK
PNK
GRY GRY
BHC2
BHC1
BHT
642
531 A1
A2
642
531 A1
A2
BH1
BHF
BH2
246
Power supply
to Booster heater
642
531 A1
A2
2
2
2
2
2
1
1
3
5
7
3
1
3
3~ 230V 50Hz
CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
WHT WHT
1
3
5
7
X6
X7
1
3
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
CN22
(BLU)
1
5
Close
Open
N
TBO.2
TBO.1
F1
F2
MXV
M
1 ~
MP2
MP1
M
1 ~
CNV1
(WHT)
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
TAB1
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
MP3
M
1 ~
IN8 IN9
IN10
TBI.3
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)(Option)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
3WV
M
1 ~
ECB2
1
2
4
6
CN01
(WHT)
Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
X15
X12
TBO.3
X11
X10
1
2
3
4
5
6
7
8
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
1
2
3
4
5
6
TBO.4
M
2WV2a
1
3
X9
X8
X13
CNIH
(ORN)
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
13
6-4. EHST20C-TM9C, EHPT20X-TM9C
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may
be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the
service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 — Water circulation pump 3 output (Space heating for Zone2) *1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1
Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BH2 Booster heater 2
BHC1 Contactor for booster heater 1
BHC2 Contactor for booster heater 2
BHCP Contactor for booster heater protection
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
1. Symbols used in wiring diagram are, : connector, : terminal
block.
2. Indoor unit and outdoor unit connecting wires have polarities, make
sure to match terminal numbers (S1, S2, S3) for correct wirings,
3. Since the outdoor unit side electric wiring may change, be sure to
check the outdoor unit electric wiring diagram for service.
OCH570

1
3
5
7
X6
X7
1
3
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
CN22
(BLU)
1
5
Close
Open
N
TBO.2
TBO.1
F1
F2
MXV
M
1 ~
MP2
MP1
M
1 ~
CNV1
(WHT)
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
TAB1
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
MP3
M
1 ~
IN8 IN9
IN10
TBI.3
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)(Option)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
3WV
M
1 ~
ECB2
1
2
4
6
CN01
(WHT)
X15
X12
TBO.3
X11
X10
1
2
3
4
5
6
7
8
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
1
2
3
4
5
6
TBO.4
M
2WV2a
1
3
X9
X8
X13
CNIH
(ORN)
Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
14
6-5. EHST20C-MEC, EHST20D-MEC, EHST20D-MHC
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may
be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the
service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 — Water circulation pump 3 output (Space heating for Zone2) *1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
1. Symbols used in wiring diagram are, : connector,
: terminal block.
2. Indoor unit and outdoor unit connecting wires have polarities,
make sure to match terminal numbers (S1, S2, S3) for
correct wirings,
3. Since the outdoor unit side electric wiring may change, be
sure to check the outdoor unit electric wiring diagram for
service. Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB2
Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
OCH570

Tool
Tool
Conductor Conductor
Outline view Top view
<How to use TBO.1 to 4>
Connect them using either way as shown below.
NL S3S2S1
NL S3S2S1
To outdoor
unit
TB1
ORN ORN
YLW
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
BLK BLK
BLK
BLK
1
3
ORN
BRN CN3C
(BLU) ORN
ORN
BRN
YLW
Indoor unit powered
by independent source
Indoor unit powered
via outdoor unit
CIRCUIT BREAKER
1
3
CN3C
(BLU)
1
3
CNPWM
(WHT)
LED1
LED2
LED3
LED4
TBI.1
TBI.2
1310 12 141174 65 932 811310 12 141174 65 932 811310 12 141174 65 932 81
IN6 IN1 IN2 IN3 IN4 IN5 IN7
THW8 THW7 THW6 THW9
THWB1 THWB2
t ° t ° t ° t ° t ° t °
Main
controller
1
+
- + - + -
2
12
CN20
(RED)
TH1
t °
13
CN21
(YLW)
TH2
t °
14
THW1 THW2
CNW12
(RED)
t ° t °
12
THW5 CNW5
(WHT)
t °
CN108
5
1
Wireless receiver
(Option)
WiFi adapter
(Option)
5
1
5
1
CNRF
(WHT)
CN105
(RED)
CN22
(BLU)
1
3
5
7
1
5
Close
Open
N
X6
X7
TBO.2
TBO.1
F1
F2
MXV
M
1 ~
MP2
MP1
M
1 ~
1
3
CNV1
(WHT)
1
3CNBHT
(BLK)
CNBC
(GRY)
CNBH
(WHT)
X4
X14
X3
X2
X1
X5B
X5A
1
2
3
4
5
6
1
2
3
4
5
6
1
1
3
3
3
CNP1
(WHT)
CNP4
(RED)
CNPWM
(WHT)
TBO.1
TBO.2
TBO.3
TBO.4
CNP1
(WHT)
CNP4
(RED)
CNV1
(WHT)
CN22
(BLU)
CNIT
(BLU)
TAB1
CN01
(WHT)
F2 F1
6.3A 250V 10A 250V
SW1
SW2
SW3
SW4
SW5
1
8
1
8
1
1
5
1
3
1
3
8
1
8
1
6
CN01
(WHT)
CN01
(WHT)
2
1
4
6
2
1
1
2
4
6
4
6
CNBH
(WHT)
CNBC
(GRY)
1
1
3
1
2
1
2
1
2
CNBHT
(BLK)
1
3
7
1
3
CNIH
(ORN)
1
4
1
3
CNW5
(WHT)
CN21
(YLW)
CNW12
(RED)
CN20
(RED)
TBI.2
MP3
M
1 ~
IN8 IN9
IN10
TBI.3
TBI.3
1
4
CN1A
(WHT)
TBI.1
2WV2b
M
1 ~
M
1 ~
MP4
M
1 ~
1
3
L
(1)
N
(3)
ORN
RED
BLU BLU
RED
ORN
IHC
IHT
IH
642
531 A1
A2
A B
24
Immersion heater (1Ph3kW)
Power supply
to Immersion heater
~/N 230V 50Hz
1
2
CNIH
(ORN)
3
3WV
M
1 ~
ECB2
1
2
4
6
CN01
(WHT)
X15
X12
TBO.3
X11
X10
1
2
3
4
5
6
7
8
Signal output
(Boiler)
Signal output
(Error)
Signal output
(Defrost)
Signal output
(Comp ON)
1
2
3
4
5
6
TBO.4
M
2WV2a
1
3
X9
X8
X13
CNIH
(ORN)
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
7
8
1
2
3
4
5
6
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
12 146108
137119
4
53
2
1
15
6-6. EHPT20X-MHCW, EHST20C-MHCW, EHST20D-MHCW
1. Symbols used in wiring diagram are, : connector, :
terminal block.
2. Indoor unit and outdoor unit connecting wires have polarities, make
sure to match terminal numbers (S1, S2, S3) for correct wirings,
3. Since the outdoor unit side electric wiring may change, be sure to
check the outdoor unit electric wiring diagram for service.
Table 1 Signal Inputs
Name Terminal block Connector Item OFF (Open) ON (Short)
IN1 TBI.1 13-14 — Room thermostat 1 input Refer to SW2-1 in <6-7. DIP switch setting>.
IN2 TBI.1 11-12 — Flow switch 1 input Refer to SW2-2 in <6-7. DIP switch setting>.
IN3 TBI.1 9-10 — Flow switch 2 input (Zone1) Refer to SW3-2 in <6-7. DIP switch setting>.
IN4 TBI.1 7-8 — Demand control input Normal Heat source OFF/ Boiler operation *2
IN5 TBI.1 5-6 — Outdoor thermostat input *1 Standard operation Heater operation/ Boiler operation *2
IN6 TBI.1 3-4 — Room thermostat 2 input Refer to SW3-1 in <6-7. DIP switch setting>.
IN7 TBI.1 1-2 — Flow switch 3 input (Zone2) Refer to SW3-3 in <6-7. DIP switch setting>.
IN8 TBI.3 1-2 — Electric energy meter 1
Refer to <6-7. DIP switch setting>.IN9 TBI.3 3-4 — Electric energy meter 2
IN10 TBI.3 5-6 — Heat meter
*1. If using outdoor thermostat for controlling operation of heaters, the lifetime of the heaters and related parts may
be reduced.
*2. To turn on the boiler operation, use the main controller to select “Boiler” in “External input setting“ screen in the
service menu.
Table 2 Outputs
Name Terminal block Connector Item OFF ON
OUT1 TBO.1 1-2 CNP1 Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2 TBO.1 3-4 — Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3 TBO.1 5-6 — Water circulation pump 3 output (Space heating for Zone2) *1 OFF ON
2-way valve 2b output *2
OUT4 TBO.2 4-6 CNV1 3-way valve output Heating DHW
OUT5
TBO.2 1-2 —Mixing valve output *1 Stop Close
TBO.2 2-3 Open
OUT6 — CNBH 1-3 Booster heater 1 output OFF ON
OUT7 — CNBH 5-7 Booster heater 2 output OFF ON
OUT9 TBO.4 3-4 CNIH Immersion heater output OFF ON
OUT10 TBO.3 1-2 — Boiler output OFF ON
OUT11 TBO.3 3-4 — Error output Normal Error
OUT12 TBO.3 5-6 — Defrost output Normal Defrost
OUT13 TBO.4 1-2 — 2-way valve 2a output *2 OFF ON
OUT14 — CNP4 Water circulation pump 4 output (DHW) OFF ON
OUT15 TBO.3 7-8 — Comp ON signal OFF ON
Do not connect to the terminals that are indicated as “—” in the “Terminal block” eld.
*1. For 2-zone temperature control.
*2. For 2-zone valve ON/OFF control.
Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB2
Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump 1(Space heating & DHW)
MP2 Water circulation pump 2 (Space heating for Zone1)(Local supply)
MP3 Water circulation pump 3 (Space heating for Zone2)(Local supply)
MP4 Water circulation pump 4 (DHW)
3WV 3-way valve
2WV2a 2-way valve (For Zone 1)(Local supply)
2WV2b 2-way valve (For Zone 2)(Local supply)
MXV Mixing valve (Local supply)
IHT Thermostat (xed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
Symbol Name
TH1 Thermistor (Room temp.)(Option)
TH2 Thermistor (Ref. liquid temp.)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 ow temp.)(Option)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 ow temp.)(Option)
THW9 Thermistor (Zone2 return temp.)(Option)
THWB1 Thermistor (Boiler ow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Local supply)
IN2 Flow switch 1 (Local supply)
IN3 Flow switch 2 (Local supply)
IN4 Demand control (Local supply)
IN5 Outdoor thermostat (Local supply)
IN6 Room thermostat 2 (Local supply)
IN7 Flow switch 3 (Local supply)
IN8 Electric energy meter 1 (Local supply)
IN9 Electric energy meter 2 (Local supply)
IN10 Heat meter (Local supply)
FLOW TEMP. CONTROLLER (FTC5)
TBO.1-4 Terminal block <Outputs>
TBI.1-3 Terminal block <Signal Inputs, Thermistor>
F1 Fuse (T10AL250V)
F2 Fuse (T6.3AL250V)
SW1-5 DIP switch *See 6-7. DIP switch setting.
X1-15 Relay
LED1 Power supply (FTC5)
LED2 Power supply (Main controller)
LED3 Communication (FTC5-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM Pump speed control signal for MP1
CN108 SD card connector
OCH570

16
Automatic switch to backup heat source operation
Back-up heat source operation (*1) will automatically run when the outdoor 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, P6, P8, U1 to U8, UD, UE, UF, UL, UP
(*1) Prolonged running of the back-up operation may affect the life of the heat source.
(*2) For safety reasons, this function is not available for certain faults. (System operation must be stopped and only pump keeps running.)
6-7. DIP switch setting
Located on the FTC 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.
Before changing any switch settings, ensure power supplies to indoor and out-
door units are isolated/powered off.
DIP switch Function OFF ON Default settings:
Indoor unit model
SW1 SW1-1 Boiler WITHOUT Boiler WITH Boiler OFF
SW1-2 Heat pump maximum outlet water temperature 55ºC 60ºC ON *1
SW1-3 DHW tank WITHOUT DHW tank WITH DHW tank ON
SW1-4 Immersion heater WITHOUT Immersion heater WITH Immersion heater OFF:
EH*T20*-*C
ON : EH*T20*-*HC*
SW1-5 Booster heater WITHOUT Booster heater WITH Booster heater
OFF: EH*T20*-M*C*
ON :
EH*T20*-*M 2/6/9*C
SW1-6 Booster heater function For heating only For heating and DHW
OFF: EH*T20*-M*C*
ON :
EH*T20*-*M 2/6/9*C
SW1-7 Outdoor unit type Split type Packaged type OFF: EHST20*-*M**C*
ON :
EHPT20X-*M**C*
SW1-8 Wireless remote controller WITHOUT Wireless remote controller WITH Wireless remote controller OFF
SW2 SW2-1 Room thermostat1 input (IN1) logic change
Zone1 operation stop at thermostat short Zone1 operation stop at thermostat open OFF
SW2-2 Flow switch1 input (IN2) logic change Failure detection at short Failure detection at open OFF
SW2-3 Booster heater capacity restriction Inactive Active
OFF: Except
EH*T20*-VM2*C
ON : EH*T20*-VM2*C
SW2-4 — — — OFF
SW2-5 Automatic switch to backup heat source operation
(When outdoor unit stops by error) Inactive Active *2 OFF
SW2-6 Mixing tank WITHOUT Mixing tank WITH Mixing tank OFF
SW2-7 2-zone temperature control Inactive Active *6 OFF
SW2-8 Flow sensor WITHOUT Flow sensor WITH Flow sensor ON
SW3 SW3-1 Room thermostat 2 input (IN6) logic change
Zone2 operation stop at thermostat short Zone2 operation stop at thermostat open OFF
SW3-2 Flow switch 2 input (IN3) logic change Failure detection at short Failure detection at open OFF
SW3-3 Flow switch 3 input (IN7) logic change Failure detection at short Failure detection at open OFF
SW3-4 Electric energy meter WITHOUT Electric energy meter WITH Electric energy meter OFF
SW3-5 Heating mode function *3 Inactive Active ON
SW3-6 2-zone valve ON/OFF control Inactive Active OFF
SW3-7 Heat exchanger for DHW Coil in tank External plate HEX ON
SW3-8 Heat meter WITHOUT Heat meter WITH Heat meter OFF
SW4 SW4-1 — — — OFF
SW4-2 — — — OFF
SW4-3 — — — OFF
SW4-4
Indoor unit only operation (during installation work) *4 Inactive Active OFF
SW4-5 Emergency mode (Heater only operation) Normal
Emergency mode (Heater only operation) OFF *5
SW4-6 Emergency mode (Boiler operation) Normal Emergency mode (Boiler operation) OFF *5
SW5 SW5-1 — — — OFF
SW5-2 — — — OFF
SW5-3
SW5-4
SW5-5
SW5-6
SW5-7
SW5-8 — — — OFF
Note: *1. When the cylinder unit is connected with a PUHZ-RP/SUHZ-SW outdoor unit of which maximum outlet water temperature is 55ºC, DIP SW1-2
must be changed to OFF.
*2. External output (OUT11) will be available. For safety reasons, this function is not available for certain errors. (In that case, system operation
must be stopped and only the water circulation pump keeps running.)
*3. This switch functions only when the cylinder unit is connected with a PUHZ-FRP outdoor unit. When another type of outdoor unit is con-
nected, the heating mode function is active regardless of the fact that this switch is ON or OFF.
*4. Space heating and DHW can be operated only in indoor unit, like an electric boiler. (Refer to "Indoor unit only operation" in page 44. )
*5. If emergency mode is no longer required, return the switch to OFF position.
*6. Active only when DIP SW3-6 is set to OFF.
SW1
SW3
SW4
SW2
SW5
SW5-3 SW5-4 SW5-5 SW5-6 SW5-7
EHST20C-*M*C* ON ON ON ON OFF
EHST20D-*M*C* ON OFF OFF ON OFF
EHPT20X-*M*C* OFF OFF OFF OFF OFF
Capacity code
OCH570

L
N
S1
S2
S3
S1
S2
S3
TB1
L
N
ECB1
L
N
ECB2
L
N
17
FIELD WIRING
7
Breaker abbreviation Meaning
ECB1 Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
TB1 Terminal block 1
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Outdoor unit
Power
supply
~/N
230 V
50 Hz
Power
supply
~/N
230 V
50 Hz
Power
supply
~/N
230 V
50 Hz
Wiring
circuit
breaker or
Isolating
switch
Wiring
circuit
breaker or
Isolating
switch
To control
board
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
Cylinder unit
Option 1: Cylinder unit powered via outdoor unit
<1 phase>
<Figure 7-1>
Electrical connections 1 phase
Description Power supply Capacity Breaker Wiring
Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW 16 A *1 2.5 mm²
6 kW 32 A *1 6.0 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²
Wiring
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)
Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5
Circuit
rating
Cylinder unit - Outdoor unit S1 - S2 *3 230 V AC
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC
*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.
Note: 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exiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)
3. Install an earth longer than other cables.
4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.
*1 If the installed earth leakage circuit
breaker does not have an over-current
protection function, install a breaker with
that function along the same power line.
Affix label A that is included with the manuals near each
wiring diagram for cylinder unit and outdoor units.
OCH570

L1
L2
S1
S2
S3
TB1
L2
L3
ECB1
L
N
ECB2
N
L3
L1
S1
S2
S3
L
N
18
Power
supply
3N~
400 V
50 Hz
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Power supply
3~ 400 V 50 Hz (EH*T20*-YM*C)
3~ 230 V 50 Hz (EH*T20*-TM*C)
Power
supply
~/N
230 V
50 Hz
Wiring
circuit
breaker
or
Isolating
switch
Wiring
circuit
breaker
or
Isolating
switch
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
To control
board
Outdoor unit
Cylinder unit
<3 phase>
<Figure 7-2>
Electrical connections 3 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400 V 50 Hz 9 kW 16 A *1 2.5 mm²
3~ 230 V 50 Hz 9 kW 32 A *1 6.0 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²
Wiring
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)
Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5
Circuit
rating
Cylinder unit - Outdoor unit S1 - S2 *3 230 V AC
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC
*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.
Note: 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exiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)
3. Install an earth longer than other cables.
4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.
*1 If the installed earth leakage circuit breaker
does not have an over-current protection
function, install a breaker with that function
along the same power line.
Afx label A that is included with the manuals near each
wiring diagram for cylinder unit and outdoor units.
OCH570

S1
S2
S3
L
N
L
N
CN01
CN01
CN01
CN01
S1
S2
S3
L
N
S1
S2
S3
S1
S2
S3
TB1
L
N
L
N
ECB1
ECB2
L
N
19
Initial settings
(Power supplied by
outdoor unit)
Modied settings
(Separate power
supply to the cylinder
unit)
Cylinder unit
control board
Cylinder unit
control board
White
BLACK BLACK YELLOW
BLACK
YELLOW YELLOW
YELLOW BLACK
White
Option 2: Cylinder unit powered by independent source.
If the cylinder unit and outdoor unit have separate power supplies, the following
requirements MUST be carried out:
•Changetheinterconnectedwiringinthecontrolandelectricalboxofthe
cylinder unit (see Figure 7-3).
•TurntheoutdoorunitDIPswitchSW8-3toON.
•TurnontheoutdoorunitBEFOREthecylinderunit.
•Powerbyindependentsourceisnotavailableforparticularmodelsof
outdoor unit model. For more detail, refer to the connecting outdoor unit
Installation Manual.
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
~/N
230 V
50 Hz
Earth
leakage
circuit
breaker
*1
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
~/N
230 V
50 Hz
Outdoor unit
Cylinder unit
Power
supply
~/N
230 V
50 Hz
Power
supply
~/N
230 V
50 Hz
Wiring
circuit
breaker
or
Isolating
switch
Wiring
circuit
breaker
or
Isolating
switch
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
To control
board
<1 phase>
<Figure 7-4>
Electrical connections 1 phase
<Figure 7-3>
Description Power supply Capacity Breaker Wiring
Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW 16 A *1 2.5 mm²
6 kW 32 A *1 6.0 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²
Cylinder unit power supply ~/N 230 V 50 Hz
Cylinder unit input capacity
Main switch (Breaker)
*1 16 A
Wiring
Wiring No.
× size (mm²)
Cylinder unit power supply 2 × Min. 1.5
Cylinder unit power supply earth 1 × Min. 1.5
Cylinder unit - Outdoor unit *2 2 × Min. 0.3
Cylinder unit - Outdoor unit earth —
Circuit
rating
Cylinder unit L - N *3 230 V AC
Cylinder unit - Outdoor unit S1 - S2 *3 —
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC
*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.
Note: 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exiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)
3. Install an earth longer than other cables.
4.
Please keep enough output capacity of power supply for each heater. Insufcientpowersupplycapacitymightcausechattering.
*1 If the installed earth leakage circuit breaker
does not have an over-current protection
function, install a breaker with that function
along the same power line.
Affix label B that is included with the manuals near
each wiring diagram for cylinder unit and outdoor units.
OCH570

L1
L2
S1
S2
S3
S1
S2
S3
TB1
L2
L3
ECB1
ECB2
N
L3
L1
L
N
L
N
20
<3 phase>
<Figure 7-5>
Electrical connections 3 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400 V 50 Hz 9 kW 16 A *1 2.5 mm²
3~ 230 V 50 Hz 9 kW 32 A *1 6.0 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW 16 A *1 2.5 mm²
Cylinder unit power supply ~/N 230 V 50 Hz
Cylinder unit input capacity
Main switch (Breaker)
*1 16 A
Wiring
Wiring No.
× size (mm²)
Cylinder unit power supply 2 × Min. 1.5
Cylinder unit power supply earth 1 × Min. 1.5
Cylinder unit - Outdoor unit *2 2 × Min. 0.3
Cylinder unit - Outdoor unit earth —
Circuit
rating
Cylinder unit L - N *3 230 V AC
Cylinder unit - Outdoor unit S1 - S2 *3 —
Cylinder unit - Outdoor unit S2 - S3 *3 24 V DC
*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.
Note: 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exiblecord.(Design60245IEC57)
Indoorunitpowersupplycordsshallnotbelighterthanpolychloroprenesheathedexiblecord.(Design60227IEC53)
3. Install an earth longer than other cables.
4.Pleasekeepenoughoutputcapacityofpowersupplyforeachheater.Insufcientpowersupplycapacitymightcausechattering.
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
To control
board
*1 If the installed earth leakage circuit breaker
does not have an over-current protection
function, install a breaker with that function
along the same power line.
Affix label B that is included with the manuals near
each wiring diagram for cylinder unit and outdoor units.
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
3N~
400 V
50 Hz
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Earth
leakage
circuit
breaker
*1
Power
supply
~/N
230 V
50 Hz
Power
supply
~/N
230 V
50 Hz
Outdoor unit
Cylinder unit
Wiring
circuit
breaker
or
Isolating
switch
Wiring
circuit
breaker
or
Isolating
switch
Power supply
3~ 400 V 50 Hz (EH*T20*-YM*C)
3~ 230 V 50 Hz (EH*T20*-TM*C)
OCH570