Mitsubishi Electric EHST20C-VM6HB Service Manual page 18

6-8. EHPT20X-VM2HB
Power supply
Power supply
to Booster heater
to Immersion heater
~/N 230V 50Hz ~/N 230V 50Hz
L N L N
(1) (3) (1) (3)
ECB2 ECB1
2 4 2 4
1 3 5
A1
BHCP
2 4 6 A2
BHC1
IHC
1 3 5 A1 1 3 5
A1
2 4 6 A2 2 4 6 A2
A B
BH1
IHT
2
IH
BHF
BHT
2 2
Table 1 Signal Inputs
Name Terminal block Connector
IN1 TBI.1 1-2 — Room thermostat 1 input
IN2 TBI.1 3-4 CN2F Flow switch 1 input
IN3 TBI.1 5-6 — Flow switch 2 input (Zone1)
IN4 TBI.1 7-8 — Demand control input
IN5 TBI.1 9-10 — Outdoor thermostat input *1
IN6 TBI.1 11-12 — Room thermostat 2 input
IN7 TBI.1 13-14 — Flow switch 3 input (Zone2)
*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 3-4 CNP1 Water circulation pump 1 output (Space heating & DHW)
OUT2 TBO.1 5-6 — Water circulation pump 2 output (Space heating for Zone1)
OUT3 TBO.1 7-8 — Water circulation pump 3 output (Space heating for Zone2)
OUT4 TBO.1 9-11 CNV1 3-way valve output
TBO.1 12-13
OUT5 — Mixing valve output
TBO.1 13-14
OUT6 — CNBH 1-3 Booster heater 1 output
OUT7 — CNBH 5-7 Booster heater 2 output
OUT8 TBO.2 11-12 — Booster heater 2+ output
OUT9 TBO.2 9-10 CNIH Immersion heater output
OUT10 TBO.1 1-2 — Boiler output
OUT11 TBO.2 1-2 — Error output
OUT12 TBO.2 3-4 — Defrost output
Symbol Name
TB1 Terminal block <Power supply, Outdoor unit>
ECB1 Earth leakage circuit breaker for booster heater
ECB2 Earth leakage circuit breaker for immersion heater
MP1 Water circulation pump1(Space heating & DHW)
MP2 Water circulation pump2
(Space heating for Zone1)(Field supply)
MP3 Water circulation pump3
(Space heating for Zone2)(Field supply)
3WV 3-way valve
MXV Mixing valve (Field supply)
BHT Thermostat for booster heater
BHF Thermal fuse for booster heater
BH1 Booster heater 1
BHC1 Contactor for booster heater 1
BHCP Contactor for booster heater protection
IHT Thermostat (fixed temp.) for immersion heater
IH Immersion heater
IHC Contactor for immersion heater
OCH531
F1
Signal
output
(Boiler)
F2
CNPWM
(WHT)
1
3
TBO.1
X10
3
1
CNP1
2
(WHT)
1 X1
3
M
1 ~
4
3
MP1
X2
5
M
1 ~
6
MP2
X3
7
M
8
1 ~
X4
MP3 9
10
1
M
11
1 ~ X5A
5 12
3WV
CNV1
(WHT) 13
Close
14
M
N X5B
1 ~ Open
MXV
TBO.2
X11
Signal
1
2
output
2
(Error)
Signal
X12
output 3
(Defrost)
4
5
6
7
8
1 X9
2
9
3
10
X8
CNIH 11
(ORN)
Signal
12
output
13
(Booster
heater2+)
14
1
2
3 CNBHT(BLK)
CNBH
(WHT)
X6
2
1
3 X7
5
7
2
1
3
CNBC
(GRY)
1 2
t °
Item OFF (Open)
Refer to SW2-1 in <6-13 Dip switch setting>
Refer to SW2-2 in <6-13 Dip switch setting>
Refer to SW3-2 in <6-13 Dip switch setting>
Normal
Standard operation
Refer to SW3-1 in <6-13 Dip switch setting>
Refer to SW3-3 in <6-13 Dip switch setting>
Item
Symbol Name
TH1 Thermistor (Room temp.)(Option)
THW1 Thermistor (Flow water temp.)
THW2 Thermistor (Return water temp.)
THW5 Thermistor (DHW tank water temp.)
THW6 Thermistor (Zone 1 flow temp.)(Option)
THW7 Thermistor (Zone 1 return temp.)(Option)
THW8 Thermistor (Zone 2 flow temp.)(Option)
THW9 Thermistor (Zone 2 return temp.)(Option)
THWB1 Thermistor (Boiler flow temp.)(Option)
THWB2 Thermistor (Boiler return temp.)(Option)
IN1 Room thermostat 1 (Field supply)
IN2 Flow switch 1
IN3 Flow switch 2 (Field supply)
IN4 Demand control (Field supply)
IN5 Outdoor thermostat (Field supply)
IN6 Room thermostat 2 (Field supply)
IN7 Flow switch 3 (Field supply)
CN01
(BLK)
5
3
1
CNP1(WHT)
1 3
1
TBO.1
2
3
1
4
CNV1
5
(WHT)
6
5
7
8
9
FTC4
10
11
12
13
14
TBO.2
1
2
LED3
3
4
5
6
7
8
9
10
11
1
12 CNPWM
13
(WHT)
3
14
LED4
LED2
1
CNBH
CNIH
(WHT)
(ORN)
7 3 1
CN22
CNBC 1
CNBHT
(BLU)
(GRY)
(BLK) 2
3 1 3 1
SW4
CN2F CN20 CN21 CNW12 CNW5
LED1
(YLW) (RED) (YLW) (RED) (WHT)
1
6
1 1 1
SW2
1
1
3 2 3 2
7
1
2 4 6 8 10 12 4 8 10 12 14
SW3
1 3 5 7 9 11 13 1 3 7
TBI.1 TBI.2
1
TBI.1
1 2 3 4 5 6 7 8 9 10 11 12 13
CN2F
(YLW)
1 4 1 2 1 3
t ° t ° t °
ON (Short)
Heat source OFF/Boiler operation *2
Heater operation/Boiler operation *2
OFF ON
OFF ON
OFF ON
OFF ON
Heating DHW
Stop Close
Stop Open
OFF ON
OFF ON
OFF ON
OFF ON
OFF ON
Normal Error
Normal Defrost
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
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
Cylinder unit powered
via outdoor unit
To outdoor
Power supply
unit
~/N 230V 50Hz
L N S1 S2 S3 TB1
BLK
CN01
CN01 (BLK)
5
(BLK)
5
3
3
1
1
CN3C
(BLU)
BRN
1
1
CN3C
ORN
(BLU)
3 3
CN105
(RED)
CNRF
(WHT)
CN108
SW1
8 1 8
8
14 1 2 3 4 5 6 7 8 9 10 11 12 13 14
CN22
(BLU)
1 2
t t t t t t
° ° ° ° ° °
Cylinder unit powered
by independent source.
To outdoor
unit
L N S1 S2 S3 TB1
BLK
CN01
(BLK)
5
3
1
CN3C
(BLU)
BRN
1
ORN
3
Figure 1