Hydro Unit
Electrical Connection (Hot Water Cylinder
temperature Sensor)
• Connect the hot water cylinder temperature sensor
as shown below to terminals A & B on Terminal
Block 06 in the Hydro Unit.
• Please ensure that the interconnecting cable,
between the Hydro Unit and the hot water cylinder, is
connected to earth at both ends of the cable using
the shield wire.
▼ Fig. 7-31
27-EN
Hydro unit
Additional hydro unit outputs
Alarm and Boiler Outputs
Alarm Output: L1: Alarm output
• Output enabled when the system is in alarm/fault
condition.
• Volt free contact - specification shown below:
AC230 V; 0.5 A (maximum)
DC24 V; 1 A (maximum)
• Connection details: Terminals 1 and 2
(OPERATION) on MCC-1217 TB (Refer to "Fig. 7-
32")
Boiler Control Output: L2: Boiler drive permission
output
• Output enabled when outdoor ambient temperature
<-10 °C
• Volt free contact - specification shown below:
AC230 V; 0.5 A (maximum)
DC24 V; 1 A (maximum)
• Connection details: Terminals 3 and 4 (EMG) on
MCC-1217 TB (Refer to "Fig. 7-32")
▼ Fig. 7-32
Connection Cable
TCB-PCIN3E
Display
Relay K1
CN208
PJ20
OPERATION
Display
Relay K2
Hydro unit
main control
board
Defrost and Compressor operation Outputs
Defrost output
• Display relay is ON when the system defrost.
• Volt free contact
AC230 V; 0.5 A (maximum)
DC24 V; 1 A (maximum)
• Connection details: Terminals 1 and 2
(OPERATION) on MCC-1217 TB (Refer to "Fig. 7-
33")
– 27 –
Installation Manual
Power
Supply
4
3
L2
EMG
Power
Supply
2
1
L1
Locally procured
Boiler
control
output
Alarm
output