Test Point Diagram - Mitsubishi Electric EHST20C-VM6HB Service Manual

10-7. Test point diagram

FTC4 (Controller board)
OUT10 (TBO.1 1-2)
Signal output (Boiler)
(non-voltage contact)
CNP1/OUT1 (TBO.1 3-4)
Water circulation pump1
(230V AC)
OUT2 (TBO.1 5-6)
Water circulation pump2
(Field supply) (230V AC)
OUT3 (TBO.1 7-8)
Water circulation pump3
(Field supply) (230V AC)
CNV1/OUT4 (TBO.1 9-11)
3-way valve
(9-10: 230V AC)
OUT5 (TBO.1 12-14)
Mixing valve (Field supply)
(12-13[Open]: 230VAC)
(13-14[Close]: 230VAC)
OUT11 (TBO.2 1-2)
Signal output (Error)
(230V AC)
OUT12 (TBO.2 3-4)
Signal output (Defrost) (230V AC)
CNIH/OUT9 (TBO.2 9-10)
Signal output for immersion
heater (230V AC)
OUT8 (TBO.2 11-12)
Signal output for booster heater 2+
(230V AC)
CNBHT/BHT (TBO.2 13-14)
Thermostat input for
booster heater
CNBH
Signal output for booster heater
(1-3: heater1 230V AC)
(5-7: heater2 230V AC)
CNBC
Signal output for booster heater
protection (230V AC)
CNW12
Thermistor
(1-2: Flow water temp.)
(3-4: Return water temp.)
CN21
Thermistor (Ref. liquid temp.)
CN20
Thermistor
(Room temperature)
CN2F/IN2
(TBI.1 3-4)
IN3
Flow switch 1 input
(TBI.1 5-6)
Flow switch
2 input
IN1 IN4
(TBI.1 7-8)
(TBI.1 1-2)
Demand
Room thermo-
control input
stat 1 input
OCH531
THWB1
IN5 IN7
(TBI.2 3-4)
(TBI.1 9-10) (TBI.1 13-14)
Thermistor
Outdoor ther- Flow switch 3
(Boiler flow
mostat input input
water temp.)
IN6 THW8
(TBI.1 11-12) (TBI.2 1-2)
Thermistor
Room thermo-
(Zone2 flow
stat 2 input
water temp. )
F2
6.3A/250V
THW6 THW9
(TBI.2 7-8) (TBI.2 11-12)
Thermistor Thermistor
(Zone1 flow (Zone2 return
water temp. ) water temp. )
THW7
THWB2
(TBI.2 9-10)
(TBI.2 5-6)
Thermistor
Thermistor
(Zone1 return
(Boiler return
water temp. )
water temp.)
68
F1
6.3A/250V
CN01
Power supply
(230V AC)
CN3C
Transmission
(Indoor/Outdoor)
(0 - 24V DC)
LED3
Transmission
(Indoor/Outdoor)
LED2
Power supply
(Main controller)
CNRF
Transmission (Indoor/
Wireless receiver)
(1-2: 11.5 - 13.2 V DC)
LED4
Reading or writing
data to SD card
CNPWM
Water circulation
pump 1
(2 - 3: 5V DC)
CN108
SD card
LED1
Power supply
(FTC4)
CNW5
Thermistor
(DHW tank water temp.)
CN22/RC(TBI.2 13-14)
Main controller
(10.4 - 13.7 V DC)