Mitsubishi EHST20C-YM9HB, EHPT20X-VM2HB, EHST20C-VM6B, EHST20C-VM6SB, EHPT20X-VM6HB Service Manual
...
CYLINDER UNIT
SERVICE MANUAL
R410A
[Model name]
EHST20C-VM6HB
EHST20C-YM9HB
EHST20C-VM6B
[Service Ref.]
EHST20C-VM6HB.UK
EHST20C-YM9HB.UK
EHST20C-VM6B.UK
September 2012
No. OCH531
Note:
• This manual describes only
service data of cylinder unit.
• RoHS compliant products have
<G> mark on the spec name
plate.
EHST20C-YM9B
EHST20C-VM6EB
EHST20C-YM9EB
EHST20C-VM6SB
EHPT20X-VM2HB
EHPT20X-VM6HB
EHPT20X-YM9HB
EHPT20X-VM6B
EHPT20X-YM9B
CYLINDER UNIT
EHST20C-YM9B.UK
EHST20C-VM6EB.UK
EHST20C-YM9EB.UK
EHST20C-VM6SB.UK
EHPT20X-VM2HB.UK
EHPT20X-VM6HB.UK
EHPT20X-YM9HB.UK
EHPT20X-VM6B.UK
EHPT20X-YM9B.UK
CONTENTS
1. REFERENCE MANUAL
2. SAFETY PRECAUTION
3. SPECIFICATIONS
4. PART NAMES AND FUNCTIONS
5. OUTLINES AND DIMENSIONS
6. WIRING DIAGRAM
7. FIELD WIRING
8. WATER SYSTEM DIAGRAM
9. CONTROLS
10. TROUBLESHOOTING
11. DISASSEMBLY PROCEDURE
12. SUPPLEMENTARY INFORMATION
MAIN CONTROLLER
13. SERVICE AND MAINTENANCE
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2
3
6
7
10
11
24
28
33
53
69
85
86
PARTS CATALOG (OCB531)
2
3
1
OCH531
REFERENCE MANUAL
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
PUHZ-HRP71/100VHA2
PUHZ-HRP71/100VHA2R1
PUHZ-HRP100VHA2R2
PUHZ-HRP100/125YHA
PUHZ-HRP100/125YHA2
PUHZ-HRP100/125YHA2R1
PUHZ-W50/85VHA(-BS)
PUHZ-W50/85VHAR1(-BS)
PUHZ-W50VHAR2(-BS)
PUHZ-W85VHA2.UK
PUHZ-W85VHA2-BS.UK
PUHZ-HW112/140YHA(-BS)
PUHZ-HW112/140YHA2(-BS)
PUHZ-HW112/140YHA2R1(-BS)
PUHZ-HW112/140YHA2R3(-BS)
PUHZ-HW140VHA(-BS)
PUHZ-HW140VHA2(-BS)
PUHZ-HW140VHA2R1(-BS)
PUHZ-HW140VHA2R2-BS
PUHZ-HW140VHA2R3(-BS)
PUHZ-SW40/45VHA(-BS) OCH525
PUHZ-SW75/100/120VHA(-BS)
PUHZ-SW100/125YHA(-BS)
PUHZ-SHW80/112VHA
PUHZ-SWH112/140YHA
OCH425
OCH439
OCH465
OCH439
OCH533
OCH526
3
2
OCH531
Please read the following safety precautions carefully.
SAFETY PRECAUTION
WARNING:
Precautions that must be observed to prevent injuries or death.
Mitsubishi Electric is not responsible for the failure of locally-supplied and eld-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.
•
CAUTION:
Precautions that must be observed to prevent damage to unit.
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 modied 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 qualied technician to t the parts.
Electrical
All electrical work should be performed by a qualied 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 done by qualied person.
Do not place containers with liquids in 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 or relocating, or servicing the cylinder unit, use only the specied 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 specied 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 sufcient airow 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 or coil. 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 manu-
facturer.
4
5
WARNING (SPLIT MODELS ONLY)
OCH531
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 specied thickness. (Refer to section 4.5. 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 4.5 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 packaging.) 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 specically designed for use with R410A refrigerant. The following tools are necessary to use R410A refrigerant. Contact your nearest
dealer for any questions.
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 efciency will be reduced.
Tools (for R410A)
Gravimeter
Unit
5
[1] Cautions for service
OCH531
(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
phase.)
refrigerant
cylinder of syphon stood vertically. (Refrigerant is charged from liquid
[3] Service tools
Use the service tools below as exclusive tools for R410A refrigerant.
No. Tool name Specifications
1
Gauge manifold
2
Charge hose
3
Electronic scale
4
Gas leak detector · Use the detector for R134a, R407C or R410A
5
Adaptor for reverse flow check · Attach on vacuum pump.
6
Refrigerant charge base
7
Refrigerant cylinder
8
Refrigerant recovery equipment
· Only for R410A
· Use the existing fitting
· Use high-tension side pressure of 5.3 MPa·G or over.
· Only for R410A
· Use pressure performance of 5.09 MPa·G or over.
· Only for R410A ·Top of cylinder (Pink)
· Cylinder with syphon
specifications
—
—
—
. (UNF1/2)
6
7
3
OCH531
SPECIFICATIONS
EHPT20X-
EHPT20X-
EHPT20X-
EHPT20X-
EHPT20X-
EHST20C-
EHST20C-
EHST20C-
YM9B
VM6B
YM9HB
VM6HB
VM2HB
VM6SB
YM9EB
VM6EB
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(7 bar)
90°C/0.7 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
50 Hz
3~, 400 V,
50 Hz
~/N, 230 V,
50 Hz
3~, 400 V,
50 Hz
~/N, 230 V,
*1 The environment must be frost-free.
*2 Tested under BS7206 conditions .
— — — — —
~/N, 230 V, 50 Hz
10A
~/N, 230 V,
~/N, 230 V,
3~, 400 V,
~/N, 230 V,
50 Hz
50 Hz
50 Hz
50 Hz
*3 Do not t immersion heaters without thermal cut-out.
EHST20C-
EHST20C-
EHST20C-
YM9B
VM6B
YM9HB
VM6HB
343 kg 343 kg 342 kg 342 kg 337 kg 337 kg 343 kg 326 kg 328 kg 328 kg 327 kg 327 kg
1 bar — — 1 bar
Nominal volume 12 L — — 12 L
Charge pressure
Control thermistor Heating 1 - 80°C
Pressure relief valve 0.3 MPa (3 bar)
Flow switch Min ow 5.5 l/min
Thermal Cut-out (for dry run prevention) 121°C
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
1.0 MPa
(10 bar)
Temperature and pressure relief valve 1.0 MPa
Gas 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm 15.88 mm
Liquid 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm 9.52 mm
Heating 25 - 60°C
Refrigerant
(R410A)
Cooling —
Heating 10 - 30°C
Cooling —
Flow temperature
Room temperature
(Phase, voltage, frequency)
Br ea ker (*wh e n pow ere d
Heating See outdoor unit spec table.
Cooling —
Time to raise DHW tank temp 15 - 65°C 21.75 min
Outdoor
Time to reheat 70% of DHW tank to 65°C 16 min
temperature
from independent source)
50 Hz
3~, 400 V,
50 Hz
~/N, 230 V,
50 Hz
3~, 400 V,
50 Hz
~/N, 230 V,
(Phase, voltage, frequency)
Capacity 2 kW+4 kW 3 kW+6 kW 2 kW+4 kW 3 kW+6 kW 2 kW+4 kW 3 kW+6 kW 2 kW+4 kW 2 kW 2 kW+4 kW 3 kW+6 kW 2 kW+4 kW 3 kW+6 kW
Booster heater Power supply
~/N, 230 V, 50 Hz — ~/N, 230 V, 50 Hz —
Breaker 32 A 16 A 32 A 16 A 32 A 16 A 32 A 16 A 32 A 16 A 32 A 16 A
Power supply
(Phase, voltage, frequency)
Current 26 A 13 A 26 A 13 A 26 A 13 A 26 A 9 A 26 A 13 A 26 A 13 A
Immersion heater
*3
• Joint pipe (9.52 → 6.35) PAC-SH30RJ-E
•High temperature thermistor PAC-TH011HT-E
Capacity 3 kW — 3 kW —
Current 13 A — 13 A —
Breaker 16 A — 16 A —
Weight (empty) 128 kg 128 kg 127 kg 127 kg 122 kg 122 kg 128 kg 113 kg 115 kg 115 kg 114 kg 114 kg
Weight (full)
Plate heat exchanger — — — — —
Nominal domestic hot water volume 200L
Overall unit dimensions 1600 x 595 x 680 mm (Height x Width x Depth)
Model name EHST20C-
Safety device Water circuit
Unvented expansion vessel
(Primary heating)
(Primary)
Booster heater Manual reset thermostat 90°C
DHW tank Control thermistor 40 - 70°C
• Immersion heater (1 Ph 3kW) PAC-IH03V-E
• Wireless Remote Controller PAR-WT50R-E • Remote sensor PAC-SE41TS-E
• Wireless Receiver PAR-WR51R-E • Joint pipe (15.88 → 12.7) PAC-SH50RJ-E
Primary circuit circulating Pump Grundfos UPM2 25 70 - 180
Connections Water 28 mm compression primary circuit/ 22 mm compression DHW circuit/22 mm compression solar thermal (Ancillary heating) circuit
Target temperature range
Guaranteed operating range Ambient *1 0 - 35°C ( 80 %RH)
DHW tank performance *2
Electrical data Control board Power supply
Solar (ancillary) connection — — — — — — — — — — —
Optional extras
• EHPT Accessories for UK PAC-WK01UK-E •Thermistor PAC-TH011-E
7
4
A
2
1
3
4
5
8
B
E
F
J
K
9
10
11
17
12
13
14
15
16
7
18
19
2
1
4
5
8
A
B
E
F
J
K
9
10
11
17
12
13
14
15
16
18
19
OCH531
PART NAMES AND FUNCTIONS
<EHST20C-*M*HB/*M*B> (Split model system)
Number Component
1 Automatic air vent
2 Pressure relief valve
3 Expansion vessel
4 Main controller
5 Control and electrical box
7 Immersion heater (Only for EHST20C-*M*HB)
8 DHW tank
9 3-way valve
10 Water circulation pump
11 Manual air vent
Booster heater
12
Drain cock (Booster heater)
13
14 Strainer valve
15 Flow switch
16 Drain cock (Primary circuit)
17 Drain cock (DHW tank)
18 Plate heat exchanger
19 Manometer
A DHW outlet
B Cold water inlet
E Inlet from space heating
F Outlet to space heating
J Refrigerant (Gas)
K Refrigerant (Liquid)
Figure 4-1
<EHST20C-*M*EB>
(Split model system without expansion vessel )
Number Component
1 Automatic air vent
2 Pressure relief valve
4 Main controller
5 Control and electrical box
8 DHW tank
9 3-way valve
10 Water circulation pump
11 Manual air vent
Booster heater
12
Drain cock (Booster heater)
13
14 Strainer valve
15 Flow switch
16 Drain cock (Primary circuit)
17 Drain cock (DHW tank)
18 Plate heat exchanger
19 Manometer
A DHW outlet
B Cold water inlet
E Inlet from space heating
F Outlet to space heating
J Refrigerant (Gas)
K Refrigerant (Liquid)
Figure 4-2
8
9
2
19
3
4
5
8
A
B
E
F
G
H
9
10
11
17
12
13
14
15
16
7
6
1
2
1
3
4
5
8
A
B
E
F
J
K
9
10
11
17
12
13
14
15
16
18
C
D
19
<EHST20C-VM6SB> (Solar split model system)
OCH531
Figure 4-3
Number Component
1 Automatic air vent
2 Pressure relief valve
3 Expansion vessel
4 Main controller
5 Control and electrical box
8 DHW tank
9 3-way valve
10 Water circulation pump
11 Manual air vent
Booster heater
12
Drain cock (Booster heater)
13
14 Strainer valve
15 Flow switch
16 Drain cock (Primary circuit)
17 Drain cock (DHW tank)
18 Plate heat exchanger
19 Manometer
A DHW outlet
B Cold water inlet
C Outlet to solar
D Inlet from solar
E Inlet from space heating
F Outlet to space heating
J Refrigerant (Gas)
K Refrigerant (Liquid)
<EHPT20X-VM2HB> (UK Packaged model system)
Figure 4-4
Number Component
1 Automatic air vent
2 Pressure relief valve
3 Expansion vessel
4 Main controller
5 Control and electrical box
6 Temperature and pressure relief valve (not visible)
7 Immersion heater
8 DHW tank
9 3-way valve
10 Water circulation pump
11 Manual air vent
Booster heater
12
Drain cock (Booster heater)
13
14 Strainer valve
15 Flow switch
16 Drain cock (Primary circuit)
17 Drain cock (DHW tank)
19 Manometer
A DHW outlet
B Cold water inlet
E Inlet from space heating
F Outlet to space heating
G Inlet from heat pump
H Outlet to heat pump
9
2
19
3
4
5
8
A
B
E
F
G
H
9
10
11
17
12
13
14
15
16
7
1
<EHPT20X-*M*HB/*M*B (except EHPT20X-VM2HB)> (Packaged model system)
OCH531
Number Component
1 Automatic air vent
2 Pressure relief valve
3 Expansion vessel
4 Main controller
5 Control and electrical box
7 Immersion heater (Only for EHPT20X-*M*HB)
8 DHW tank
9 3-way valve
10 Water circulation pump
11 Manual air vent
Booster heater
12
Drain cock (Booster heater)
13
14 Strainer valve
15 Flow switch
16 Drain cock (Primary circuit)
17 Drain cock (DHW tank)
19 Manometer
A DHW outlet
B Cold water inlet
E Inlet from space heating
F Outlet to space heating
G Inlet from heat pump
H Outlet to heat pump
Figure 4-5
10
11
5
445
1600
1095
595
G1/2
118
100±20
950
30
156
50
680
1831
L
H / K
G / J
F
E
D
C
B
A
63.3
561.7
509.7
491.1
449.7
123
67.8
0
47.1
550.2
541.1
522.8
492.2
470.8
0
a
b b
d
OCH531
OUTLINES AND DIMENSIONS
5-1. Technical Drawings
<Left side> <Front> <Right side>
Main controller
Temperature and
pressure relief valve
and its access plate
(EHPT20X-VM2HB)only)
Terminal block
Front panel
<Unit: mm>
Air vent
Pressure relief valve
<Top>
5-2. Service access diagrams
Service access
a 300
b 150
c
(distance behind unit not visible
d 500
Parameter Dimension (mm)
in the right gure)
Letter Pipe description Connection size/type
A DHW outlet connection 22 mm/Compression
B Cold water inlet connection 22 mm/Compression
C/D
Solar (ancillary heat source) connections
E Space heating return connection 28 mm/Compression
F Space heating ow connection 28 mm/Compression
Flow from heat pump connection
G
(No plate heat exchanger)
Return to heat pump connection
H
(No plate heat exchanger)
Refrigerant (GAS)
J
(With plate heat exchanger)
Refrigerant (LIQUID)
K
(With plate heat exchanger)
Electrical cable inlets
L
22 mm/Compression
28 mm/Compression
28 mm/Compression
15.88 mm/Flare
9.52 mm/Flare
—
For inlets and , run low-voltage wires including
external input wires and thermistor wires. For inlets ,
, and , run high-voltage wires including power cable,
indoor-outdoor cable, and external output wires.
*For a wireless receiver (option) cable, use inlet .
10
Sufcient 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.
Service access
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater
IN7 Flow switch 3 (Field supply)
IH Immersion heater
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>.
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
EHST20C-VM6HB WIRING DIAGRAM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
RED
RED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
6
95
2
1
TBI.2
1210 148
13
7
1
1
4
31
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
11
6 WIRING DIAGRAM
OCH531
6-1. EHST20C-VM6HB
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater
IN7 Flow switch 3 (Field supply)
IH Immersion heater
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L1
(1)L2(3)L3(5)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
WHT
BLK
RED
WHT
BLK
RED
BLU
BLU/No.4
WHT/No.2
WHT/No.1
BLU/No.5
WHT/No.3
BLU/No.6
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4 6
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
3~ 400V 50Hz
2
2
2
2
1
3
5
7
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
1
3
1
3
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
X9
642
531
A1
A2
WHT
BLK
RED
3
1
5
TBO.2
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
Open
Close
N
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
95
2
1
TBI.2
12610 148
13
7
1
1
4
31
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
12
13
6-2. EHST20C-YM9HB
OCH531
EHST20C-VM6B WIRING DIAGRAM
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
IN7 Flow switch 3 (Field supply)
IH Immersion heater (Option)
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater (Option)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
REDRED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 11945 953
2 2
1
TBI.2
12610 148
13
7
1
1
4
31
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
13
OCH531
6-3. EHST20C-VM6B
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
IN7 Flow switch 3 (Field supply)
IH Immersion heater (Option)
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater (Option)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
S3
TB1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L1
(1)L2(3)L3(5)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
WHT
BLK
RED
WHT
BLK
RED
BLU
BLU/No.4
WHT/No.2
WHT/No.1
BLU/No.5
WHT/No.3
BLU/No.6
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4 6
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
3~ 400V 50Hz
2
2
2
2
1
3
5
7
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
1
3
1
3
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
X9
642
531
A1
A2
WHT
BLK
RED
3
1
5
TBO.2
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
Open
Close
N
NL
S3S2S1
NL
S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
14
15
6-4. EHST20C-YM9B
OCH531
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
RED
RED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
IN7 Flow switch 3 (Field supply)
IH Immersion heater (Option)
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater (Option)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 610148
137 119453
2
1
TBI.2
1210 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
15
6-5. EHST20C-VM6EB
OCH531
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L1
(1)L2(3)L3(5)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
WHT
BLK
RED
WHT
BLK
RED
BLU
BLU/No.4
WHT/No.2
WHT/No.1
BLU/No.5
WHT/No.3
BLU/No.6
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4 6
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
3~ 400V 50Hz
2
2
2
2
1
3
5
7
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
1
3
1
3
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
X9
642
531
A1
A2
WHT
BLK
RED
3
1
5
TBO.2
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
Open
Close
N
EHST20C-YM9EB WIRING DIAGRAM
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
IN7 Flow switch 3 (Field supply)
IH Immersion heater
(Option)
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater
(Option)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
16
17
6-6. EHST20C-YM9EB
OCH531
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
TH2 Thermistor (Ref. liquid temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW1 Thermistor (Flow water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW2 Thermistor (Return water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone1 flow temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW7 Thermistor (Zone1 return temp.)(Option)
THW8 Thermistor (Zone2 flow temp.)(Option)
3WV 3-way valve THW9 Thermistor (Zone2 return temp.)(Option)
MXV Mixing valve (Field supply)
THWB1
Thermistor (Boiler flow temp.)(Option)
BHT Thermostat for booster heater
THWB2
Thermistor (Boiler return temp.)(Option)
BHF Thermal fuse for booster heater IN1 Room thermostat 1 (Field supply)
BH1 Booster heater 1 IN2 Flow switch 1
BH2 Booster heater 2 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHC2 Contactor for booster heater 2 IN5 Outdoor thermostat (Field supply)
BHCP Contactor for booster heater protection IN6 Room thermostat 2 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
IN7 Flow switch 3 (Field supply)
IH Immersion heater
(Option)
FLOW TEMP. CONTROLLER (FTC4)
IHC Contactor for immersion heater
(Option)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal Inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
REDRED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
3
CN21
(YLW)
TH2
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t°t°t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
17
6-7. EHST20C-VM6SB
OCH531
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
THW1 Thermistor (Flow water temp.)
ECB2
Earth leakage circuit breaker for immersion heater
THW2 Thermistor (Return water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW5 Thermistor (DHW tank water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
3WV 3-way valve
THWB1
Thermistor (Boiler flow temp.)(Option)
MXV Mixing valve (Field supply)
THWB2
Thermistor (Boiler return temp.)(Option)
BHT Thermostat for booster heater IN1 Room thermostat 1 (Field supply)
BHF Thermal fuse for booster heater IN2 Flow switch 1
BH1 Booster heater 1 IN3 Flow switch 2 (Field supply)
BHC1 Contactor for booster heater 1 IN4 Demand control (Field supply)
BHCP Contactor for booster heater protection IN5 Outdoor thermostat (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater
IN6 Room thermostat 2 (Field supply)
IH Immersion heater IN7 Flow switch 3 (Field supply)
IHC Contactor for immersion heater
FLOW TEMP. CONTROLLER (FTC4)
TBO.1~2
Terminal block <Outputs>
TBI.1~2
Terminal block <Signal inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t
°
t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
RED
BLU
WHT/No.2
WHT/No.1
RED
RED
VLT
VLT
GRY
GRY
ORN
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
18
19
6-8. EHPT20X-VM2HB
OCH531
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
THW1 Thermistor (Flow water temp.)
ECB2
Earth leakage circuit breaker for immersion heater
THW2 Thermistor (Return water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW5 Thermistor (DHW tank water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
3WV 3-way valve
THWB1
Thermistor (Boiler flow temp.)(Option)
MXV Mixing valve (Field supply)
THWB2
Thermistor (Boiler return temp.)(Option)
BHT Thermostat for booster heater IN1 Room thermostat 1 (Field supply)
BHF Thermal fuse for booster heater IN2 Flow switch 1
BH1 Booster heater 1 IN3 Flow switch 2 (Field supply)
BH2 Booster heater 2 IN4 Demand control (Field supply)
BHC1 Contactor for booster heater 1 IN5 Outdoor thermostat (Field supply)
BHC2 Contactor for booster heater 2 IN6 Room thermostat 2 (Field supply)
BHCP Contactor for booster heater protection IN7 Flow switch 3 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater
FLOW TEMP. CONTROLLER (FTC4)
IH Immersion heater
TBO.1~2
Terminal block <Outputs>
IHC Contactor for immersion heater
TBI.1~2
Terminal block <Signal inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
REDRED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t
°
t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
19
6-9. EHPT20X-VM6HB
OCH531
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
THW1 Thermistor (Flow water temp.)
ECB2
Earth leakage circuit breaker for immersion heater
THW2 Thermistor (Return water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW5 Thermistor (DHW tank water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
3WV 3-way valve
THWB1
Thermistor (Boiler flow temp.)(Option)
MXV Mixing valve (Field supply)
THWB2
Thermistor (Boiler return temp.)(Option)
BHT Thermostat for booster heater IN1 Room thermostat 1 (Field supply)
BHF Thermal fuse for booster heater IN2 Flow switch 1
BH1 Booster heater 1 IN3 Flow switch 2 (Field supply)
BH2 Booster heater 2 IN4 Demand control (Field supply)
BHC1 Contactor for booster heater 1 IN5 Outdoor thermostat (Field supply)
BHC2 Contactor for booster heater 2 IN6 Room thermostat 2 (Field supply)
BHCP Contactor for booster heater protection IN7 Flow switch 3 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater
FLOW TEMP. CONTROLLER (FTC4)
IH Immersion heater
TBO.1~2
Terminal block <Outputs>
IHC Contactor for immersion heater
TBI.1~2
Terminal block <Signal inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t
°
t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L1
(1)L2(3)L3(5)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
WHT
BLK
RED
WHT
BLK
RED
BLU
BLU/No.4
WHT/No.2
WHT/No.1
BLU/No.5
WHT/No.3
BLU/No.6
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4 6
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
3~ 400V 50Hz
2
2
2
2
1
3
5
7
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
1
3
1
3
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
X9
642
531
A1
A2
WHT
BLK
RED
3
1
5
TBO.2
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
Open
Close
N
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
20
21
6-10. EHPT20X-YM9HB
OCH531
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
THW1 Thermistor (Flow water temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW2 Thermistor (Return water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW5 Thermistor (DHW tank water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
3WV 3-way valve
THWB1
Thermistor (Boiler flow temp.)(Option)
MXV Mixing valve (Field supply)
THWB2
Thermistor (Boiler return temp.)(Option)
BHT Thermostat for booster heater IN1 Room thermostat 1 (Field supply)
BHF Thermal fuse for booster heater IN2 Flow switch 1
BH1 Booster heater 1 IN3 Flow switch 2 (Field supply)
BH2 Booster heater 2 IN4 Demand control (Field supply)
BHC1 Contactor for booster heater 1 IN5 Outdoor thermostat (Field supply)
BHC2 Contactor for booster heater 2 IN6 Room thermostat 2 (Field supply)
BHCP Contactor for booster heater protection IN7 Flow switch 3 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
FLOW TEMP. CONTROLLER (FTC4)
IH Immersion heater (Option)
TBO.1~2
Terminal block <Outputs>
IHC Contactor for immersion heater (Option)
TBI.1~2
Terminal block <Signal inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L
(1)N(3)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
BLU
BLU
BLU
RED
RED
BLU
BLU/No.3
WHT/No.2
WHT/No.1
BLU/No.4
RED
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
~/N 230V 50Hz
2
2
2
2
1
3
5
7
1
5
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
TBO.2
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
1
3
1
3
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
TBO.1
X9
642
531
A1
A2
Open
Close
N
3
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t
°
t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
21
6-11. EHPT20X-VM6B
OCH531
Symbol Name Symbol Name
TB1
Terminal block <Power supply, Outdoor unit>
TH1 Thermistor (Room temp.)(Option)
ECB1
Earth leakage circuit breaker for booster heater
THW1 Thermistor (Flow water temp.)
ECB2
Earth leakage circuit breaker for immersion heater (Option)
THW2 Thermistor (Return water temp.)
MP1
Water circulation pump1(Space heating & DHW)
THW5 Thermistor (DHW tank water temp.)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
3WV 3-way valve
THWB1
Thermistor (Boiler flow temp.)(Option)
MXV Mixing valve (Field supply)
THWB2
Thermistor (Boiler return temp.)(Option)
BHT Thermostat for booster heater IN1 Room thermostat 1 (Field supply)
BHF Thermal fuse for booster heater IN2 Flow switch 1
BH1 Booster heater 1 IN3 Flow switch 2 (Field supply)
BH2 Booster heater 2 IN4 Demand control (Field supply)
BHC1 Contactor for booster heater 1 IN5 Outdoor thermostat (Field supply)
BHC2 Contactor for booster heater 2 IN6 Room thermostat 2 (Field supply)
BHCP Contactor for booster heater protection IN7 Flow switch 3 (Field supply)
IHT
Thermostat (fixed temp.) for immersion heater (Option)
FLOW TEMP. CONTROLLER (FTC4)
IH Immersion heater (Option)
TBO.1~2
Terminal block <Outputs>
IHC Contactor for immersion heater (Option)
TBI.1~2
Terminal block <Signal inputs,Thermistor>
F1~F2
Fuse (T6.3AL250V)
SW1~4
Dip switch *See <6-13 Dip switch setting>
X1~X12
Relay
LED1 Power supply (FTC4)
LED2 Power supply (Main controller)
LED3 Communication (FTC4-Outdoor unit)
LED4 Reading or writing data to SD card
CNPWM
Pump speed control signal for MP1
CN108
SD card connector
Table 1 Signal Inputs
Name
Terminal block Connector
Item OFF (Open) ON (Short)
IN1 TBI.1 1-2
— Room thermostat 1 input
Refer to SW2-1 in <6-13 Dip switch setting>
IN2 TBI.1 3-4 CN2F
Flow switch 1 input
Refer to SW2-2 in <6-13 Dip switch setting>
IN3 TBI.1 5-6
— Flow switch 2 input (Zone1)
Refer to SW3-2 in <6-13 Dip switch setting>
IN4 TBI.1 7-8
— Demand control input
Normal
Heat source OFF/Boiler operation *2
IN5 TBI.1 9-10
— Outdoor thermostat input *1
Standard operation
Heater operation/Boiler operation *2
IN6 TBI.1 11-12
— Room thermostat 2 input
Refer to SW3-1 in <6-13 Dip switch setting>
IN7 TBI.1 13-14
— Flow switch 3 input (Zone2)
Refer to SW3-3 in <6-13 Dip switch setting>
*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.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2 2
2 2 2
ECB1
L1
(1)L2(3)L3(5)
L
(1)N(3)
ECB2
BHCP
ORN
RED
BLU
WHT
BLK
RED
WHT
BLK
RED
BLU
BLU/No.4
WHT/No.2
WHT/No.1
BLU/No.5
WHT/No.3
BLU/No.6
RED
VLT
VLT
PNK
PNK
GRY
GRY
ORN
BHC2
IHC
BHC1
BHT
IHT
IH
642
531
A1
A2
642
531
A1
A2
642
531
A1
A2
BH1
A B
BHF
BH2
2
4 6
2
4
Power supply
to Immersion heater
~/N 230V 50Hz
Power supply
to Booster heater
3~ 400V 50Hz
2
2
2
2
1
3
5
7
X1
X2
X3
X4
X5A
X12
X11
X6
X8
X7
5
3
1
F1
F2
CN01
(BLK)
Signal
output
(Error)
Signal
output
(Defrost)
Signal
output
(Booster
heater2+)
1
3
1
3
CNIH
(ORN)
2
1
3
CNBHT(BLK)
X5B
X10
CNBC
(GRY)
CNBH
(WHT)
X9
642
531
A1
A2
WHT
BLK
RED
3
1
5
TBO.2
3WV
M
1
~
MXV
M
1
~
M
1
~
MP2
M
1
~
MP3
MP1
M
1
~
1
3
CNP1
(WHT)
Signal
output
(Boiler)
CNV1
(WHT)
1
3
CNPWM
(WHT)
Open
Close
N
NL
S3S2S1
NL
S3S2S1
Figure 1
To outdoor
unit
TB1
ORN
ORN
YLW
BLK
BLK
YLW
GRN/YLW
To outdoor
unit
Power supply
~/N 230V 50Hz
TB1
ORN
BLU
RED
BLU
RED
YLW
GRN/YLW
1
3
CN3C
(BLU)
5
3
1
1
3
5
3
1
CN01
(BLK)
ORN
BRN
CN3C
(BLU)
CN01
(BLK)
ORN
ORN
BRN
YLW
Cylinder unit powered
by independent source.
Cylinder unit powered
via outdoor unit
CIRCUIT
BREAKER
TBO.1
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBO.2
FTC4
3
9
5
1
7
2
8
4
6
11
10
12
13
14
TBI.1
126 10148
137 119453
2
1
TBI.2
12610 148
13
7
1
1
9
4
5
321
1 3
CNP1(WHT)
1
5
CNV1
(WHT)
1
3
CN3C
(BLU)
5
3
1
CN01
(BLK)
1 8
SW3
1 8
SW1
LED1
LED3
118
6
SW2
SW4
TBI.1
1310121411
7
4 6
5 9
3
2
81
TBI.2
1310121411
7
4 6
5 9
3
2
81
1
2
CN20
(RED)
TH1
1
4
THW1
1
2
1
3
IN2
IN7
IN6
IN5
IN4
IN3
IN1
t°t
°
THWB2
THWB1
THW8
t
°
THW6
t
°
THW7
t
°
THW9
t
°
Main
controller
1
2
THW2
THW5
CNW5
(WHT)
CNW12
(RED)
t
°
t°t°t
°
1
3
1
7
CN2F
(YLW)
CN20
(RED)
CN21
(YLW)
CNW12
(RED)
CNW5
(WHT)
1
2
1
2
CN108
1
3
13
13
CNBH
(WHT)
CNBHT
(BLK)
13
CNIH
(ORN)
CNBC
(GRY)
1
7
LED4
LED2
1
2
CN22
(BLU)
CNPWM
(WHT)
1
3
5
1
Wireless receiver
(Option)
CNRF
(WHT)
5
1
CN105
(RED)
CN2F
(YLW)
CN22
(BLU)
Table 2 Outputs
Name
Terminal block Connector
Item OFF ON
OUT1
TBO.1 3-4
CNP1
Water circulation pump 1 output (Space heating & DHW) OFF ON
OUT2
TBO.1 5-6
—
Water circulation pump 2 output (Space heating for Zone1) OFF ON
OUT3
TBO.1 7-8
—
Water circulation pump 3 output (Space heating for Zone2) OFF ON
OUT4
TBO.1 9-11
CNV1
3-way valve output Heating DHW
OUT5
TBO.1 12-13
—
Mixing valve output
Stop Close
TBO.1 13-14 Stop Open
OUT6
—
CNBH 1-3
Booster heater 1 output OFF ON
OUT7
—
CNBH 5-7
Booster heater 2 output OFF ON
OUT8
TBO.2 11-12
—
Booster heater 2+ output OFF ON
OUT9
TBO.2 9-10
CNIH
Immersion heater output OFF ON
OUT10
TBO.1 1-2
—
Boiler output OFF ON
OUT11
TBO.2 1-2
—
Error output Normal Error
OUT12
TBO.2 3-4
—
Defrost output Normal Defrost
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 servicing.
4. This diagram shows the wiring of indoor unit and
outdoor unit connecting wires (specification of 230V),
adopting superimposed system of power and signal.
When work to supply power separately to indoor
unit and outdoor unit was applied, refer to Figure 1.
22
23
6-12. EHPT20X-YM9B
OCH531
23
6-13. Dip switch setting
OCH531
Located on the FTC4 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 outdoor units are isolated/powered off.
SW4
SW2
SW1
SW3
Dip switch Function OFF ON
SW1
SW1-1 Boiler WITHOUT Boiler WITH Boiler OFF
SW1-2
Heat pump maximum outlet water temperature
SW1-3
DHW tank WITHOUT DHW tank WITH DHW tank ON
SW1-4 Immersion heater WITHOUT Immersion heater WITH Immersion heater
SW1-5 Booster heater WITHOUT Booster heater WITH Booster heater ON
SW1-6 Booster heater function For heating only For heating and DHW ON
SW1-7 Outdoor unit type Split type Packaged type
SW1-8 Wireless remote controller WITHOUT Wireless remote controller WITH Wireless remote controller OFF
SW2
SW2-1
Room thermostat1 input (IN1) logic change
Flow switch1 input (IN2) logic change Failure detection at short Failure detection at open ON
SW2-2
SW2-3
Booster heater capacity restriction Inactive Active
SW2-4
Automatic switch to backup heat source
SW2-5
operation (When outdoor unit stops by error)
SW2-6
Mixing tank WITHOUT Mixing tank WITH Mixing tank OFF
SW2-7
2-zone temperature control Inactive Active OFF
SW2-8
SW3
SW3-1
Room thermostat 2 input (IN6) logic change Zone2 operation stop at thermostat short Zone2 operation stop at thermostat open
Flow switch 2 input (IN3) logic change Failure detection at short Failure detection at open OFF
SW3-2
Flow switch 3 input (IN7) logic change Failure detection at short Failure detection at open OFF
SW3-3
SW3-4
SW3-5
Heating mode function *3 Inactive Active OFF
SW3-6
SW3-7
SW3-8
SW4
SW4-1 — — — OFF
SW4-2
SW4-3
SW4-4 — — — OFF
SW4-5 Emergency mode (Heater only operation) Normal
SW4-6 Emergency mode (Boiler operation) Normal
Note:
1. When the cylinder unit is connected with a PUHZ-RP 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. If emergency mode is no longer required, return the switch to OFF position.
— — — OFF
— — — OFF
— — — OFF
— — — OFF
— — — OFF
— — — OFF
— — — OFF
— — — OFF
55ºC 60ºC ON *1
Zone1 operation stop at thermostat short Zone1 operation stop at thermostat open
Inactive Active *2 OFF
Emergency mode (Heater only operation)
(To be activated only when powered ON)
Emergency mode (Boiler operation)
(To be activated only when powered ON)
Default settings:
Indoor unit model
OFF:
Except
EHST20C-*M*HB
EHPT20-*M*HB
ON : EHST20C-*M*HB
EHPT20X-*M*HB
OFF: EHST20C-*M**B
ON : EHPT20X-*M**B
OFF
OFF: Except
EHPT20X-VM2HB
ON : EHPT20X-VM2HB
OFF
OFF *4
OFF *4
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.)
7
L
N
S1
S2
S3
S1
S2
S3
TB1
L
N
ECB1
L
N
ECB2
L
N
OCH531
FIELD WIRING
Breaker abbreviation Meaning
ECB1 Earth leakage circuit breaker for booster heater
ECB2
Earth leakage circuit breaker for immersion heater
TB1 Terminal block 1
Option 1: Cylinder unit powered via outdoor unit
<1 phase>
Power
supply
~/N
230V
50Hz
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
~/N
230V
50Hz
Power
supply
~/N
230V
50Hz
Outdoor unit
Wiring
breaker or
Isolating
switch
breaker or
Isolating
circuit
Wiring
circuit
switch
Cylinder unit
To control
board
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
*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.
*2 Afx label A which is included with the manuals near each wiring diagram for cylinder unit and outdoor units
<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 (EHPT20X-VM2H*) 16 A *1 2.5 mm²
6 kW (EH*T20*-VM6**) 32 A *1
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW (EH*T20*-VM*H*) 16 A *1 2.5 mm²
6.0 mm²
Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)
Wiring
Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit S1 - S2 *3 230V AC
rating
Cylinder unit - Outdoor unit S2 - S3 *3 24V DC
Circuit
*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. Insufcient power supply capacity might cause chattering.
24 25
L1
L2
S1
S2
S3
TB1
L2
L3
ECB1
L
N
ECB2
N
L3
L1
S1
S2
S3
L
N
<3 phase>
OCH531
Cylinder unit
Outdoor unit
To control
Power
supply
3N~
400V
50Hz
Earth
leakage
circuit
breaker
*1
Wiring
circuit
breaker
or
Isolating
switch
Power
supply
3~
400V
50Hz
Power
supply
~/N
230V
50Hz
Wiring
circuit
breaker
or
Isolating
switch
Wiring
circuit
breaker
or
Isolating
switch
board
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
*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.
*2 Afx label A which is included with the manuals near each wiring diagram for cylinder unit and outdoor
Electrical connections 3 phase
<Figure 7-2>
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400V 50Hz 9 kW 16 A *1 2.5 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3kW (EH*T20*-YM9H*) 16 A *1 2.5 mm²
Cylinder unit - Outdoor unit *2 3 × 1.5 (polar)
Wiring
Cylinder unit - Outdoor unit earth *2 1 × Min. 1.5
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit S1 - S2 *3 230V AC
rating
Circuit
Cylinder unit - Outdoor unit S2 - S3 *3 24V 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
The values given in the table above are not always measured against the ground value.
*3.
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. Insufcient power supply capacity might cause chattering.
26
27
S1
S2
S3
L
N
L
N
CN01
CN01
CN01
CN01
S1
S2
S3
Option 2: Cylinder unit powered by independent source.
L
N
S1
S2
S3
S1
S2
S3
TB1
L
N
ECB1
L
N
ECB2
L
N
OCH531
If the cylinder unit and outdoor unit have separate power supplies, the following
requirements MUST be carried out:
• Change the connector connections 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.
Initial settings
(Power supplied by
outdoor unit)
BLACK
BLACK
YELLOW
YELLOW
YELLOW
Black
Cylinder unit
control board
BLACK
<1 phase>
Power
supply
~/N
230V
50Hz
Earth
leakage
circuit
breaker
*1
Power
supply
~/N
230V
50Hz
Wiring
circuit
breaker
or
Isolating
switch
Earth
leakage
circuit
breaker
*1
Power
supply
~/N
230V
50Hz
Power
supply
~/N
230V
50Hz
breaker
Isolating
Outdoor unit
Isolating
Wiring
circuit
or
switch
Wiring
circuit
breaker
or
switch
Wiring
circuit
breaker
or
Isolating
switch
Modied settings
(Separate power
supply to the cylinder
unit)
Cylinder unit
To control
board
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
BLACK
<Figure 7-3>
YELLOW
Black
Cylinder unit
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.
*2 Afx label B which is included with the manuals near each wiring diagram for cylinder unit and outdoor units.
<Figure 7-4>
Electrical connections 1 phase
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) ~/N 230 V 50 Hz 2 kW (EHPT20X-VM2H*) 16 A *1 2.5 mm²
6 kW (EH*T20X-VM6**) 32 A *1
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3 kW (EH*T20*-VM*H*) 16 A *1 2.5 mm²
Cylinder unit power supply ~/N 230 V 50 Hz
Cylinder unit input capacity
Main switch (Breaker)
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
Wiring
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit earth —
Cylinder unit L - N *3 230V AC
Cylinder unit - Outdoor unit S1 - S2 *3
rating
Circuit
Cylinder unit - Outdoor unit S2 - S3 *3 24V 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.
*1
*2. Max. 120 m
The values given in the table above are not always measured against the ground value.
*3.
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. Insufcient power supply capacity might cause chattering.
16 A
—
6.0 mm²
27
L1
L2
S1
S2
S3
S1
S2
S3
TB1
L2
L3
ECB1
L
N
ECB2
N
L3
L1
L
N
<3 phase>
OCH531
Cylinder unit
Wiring
circuit
breaker
or
Isolating
switch
Outdoor unit
Wiring
circuit
breaker
Isolating
switch
Wiring
circuit
breaker
Isolating
switch
or
or
To control
board
For
booster
heater
(Primary circuit)
For
Immersion
heater
(DHW tank)
Power
supply
3N~
400V
50Hz
Earth
leakage
circuit
breaker
*1
Power
supply
~/N
230V
50Hz
Wiring
circuit
breaker
or
Isolating
switch
Earth
leakage
circuit
breaker
*1
Power
supply
3~
400V
50Hz
Power
supply
~/N
230V
50Hz
*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.
*2 Afx label B which is included with the manuals near each wiring diagram for cylinder unit and outdoor units.
Electrical connections 3 phase
<Figure 7-5>
Description Power supply Capacity (Indoor unit Ref.) Breaker Wiring
Booster heater (Primary circuit) 3~ 400V 50Hz 9 kW 16 A *1 2.5 mm²
Immersion heater (DHW tank) ~/N 230 V 50 Hz 3kW (EH*T20*-YM9H*) 16 A *1 2.5 mm²
Cylinder unit power supply ~/N 230 V 50 Hz
Cylinder unit input capacity
Main switch (Breaker)
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
Wiring
Wiring No.
× size (mm²)
Cylinder unit - Outdoor unit earth —
Cylinder unit L - N *3 230V AC
Cylinder unit - Outdoor unit S1 - S2 *3
rating
Circuit
Cylinder unit - Outdoor unit S2 - S3 *3 24V 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
The values given in the table above are not always measured against the ground value.
*3.
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)
3. Install an earth longer than other cables.
4. Please keep enough output capacity of power supply for each heater. Insufcient power supply capacity might cause chattering.
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed exible cord. (Design 60227 IEC 53)
*1
16 A
—
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