Mitsubishi Electric EHST20C-VM2C.UK Service Manual page 15

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