Hitachi YUTAKI Series Service Manual page 123

Controller pack
Service Manual
Terminal block C (inputs)
-
4-20mA
T DHW
T RET
T SUP
T EXT
Bi-Valent system - parallel operation - mixing loop 'conf 4'
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This system is recommended for retrofit (upgrade) applications where an existing gas/oil boiler will be retained to provide the
full heating requirements on the coldest days of the year.
• Direct OTC Controlled Heating Loop - Mixing circuit
• Sequence control of boiler and heat pump
● Important settings
• Set installer parameter CONF to value 4
• Set P4 (OTC heating curve) according to building/ system
● Additional settings
• Boiler control parameters
• Mixing valve control parameters
• Minimum and maximum supply temperatures
• Room temperature compensation
• Frost Protection parameters
• Summer switch-off setting
• Tariff/ Timer input configuration
• To select alternative operation (heat pump or boiler can operate
separately, but not at the same time)
Terminal block C (inputs)
Mixed supply
T MIX
sensor
-
Heat pump control
4-20mA
output
Tariff/ Timer input
RF Receiver
Heat pump fault
Return sensor
T RET
Supply sensor
T SUP
Outdoor sensor
T EXT
Terminal block A (outputs)
Heat pump
control output
1 2 3
Tariff/ Timer input
DHW Sensor
RF Receiver
Heat pump fault
Return sensor
Supply sensor
Outdoor sensor
Terminal block A (outputs)
1 2 3 5
4
Terminal block B (Power Supply)
4 5 6 7 8 9 10 11 12
- Heat Pump
- Boiler
- Secondary pump
- Mixing valve
- Optional boiler primary pump
Terminal block B (Power Supply)
6 7 8 9 11
10 12
N
N
L
N
N
L
SMGB0066 rev.0 - 12/2009
System configurations
4
121