Hitachi YUTAKI Series - Page 119

117
Electrical wiring
SMGB0066 rev.0 - 12/2009
Controller pack
Service Manual
4
12
11
10
Boiler
ON/OFF
TERMINAL
BLOCK A

It is possible to connect an external time clock to the System Controller to provide time-of-day switching of the DHW storage.
TheinputcanbeconguredsothatheatingoftheDHWstoragetankisblocked(disabled)oneitheranopencircuitorclosed
circuit condition.
P24CongurationofTariff/TimerInput
NotethattheTariff/Timerinput(terminals10&11)canbeusedforDHWTimeSwitchingORTariff-Switching,notboth.
  
0 Tariff/Timer Input is ignored
1 Tariff/Timer input is used for Heat Pump blocking
2 Tariff/Timer input is used for Heat Pump blocking
3 DHW is blocked DHW is enabled
4 DHW is enabled DHW is blocked



1110

Ifatariff-switchingdevice(loadsheddingmanagement)isprovidedbytheelectricityutility,itcanbeusedtopreventthe
heatpumpswitchingon,andtheSystemControllerwillusetheboilerinsteadtosatisfytheheatingrequirements(bi-valent
systemsonly).Theinputcanbeconguredsothattheheatpumpisblocked(disabled)oneitheranopencircuitorclosed
circuit condition.
P24CongurationofTariff/TimerInput
NotethattheTariff/Timerinput(terminals10&11)canbeusedforDHWTimeSwitchingORTariff-Switching,notboth.
  
0 Tariff/Timer Input is ignored
1 Heat Pump is enabled Heat Pump is blocked
2 Heat Pump is blocked Heat Pump is enabled
3 Tariff/Timer input is used for DHW time clock
4 Tariff/Timer input is used for DHW time clock
TERMINAL
BLOCK C
Tariff input
1110

All sensors used are of type NTC 20K (at 25°C).
• Theoutdoorsensor(TEXT)isusedfortheOTCcontrol,frostprotection,summerswitch-off,andbi-valentsystem
management.
• TheDHWsensor(TDHW)isusedtocontrolthedomestichotwaterstoragetank.
• Thesupplysensor(TSUP)isusedtocontrolthewatertemperaturefromtheheatsources.Pleaseseehydraulic
diagrams for sensor positioning.
• Themixedsupplysensor(TMIX)isusedinsystemswithamixingvalve(CONF4&5only)andshouldbepositioned
after the mixing valve and the circulation pump.
• Thereturnwatersensor(TRET)isusedtocontroltheheatpumpreturntemperatureprotectionandshouldbe
positioned on the return pipe to the heat pump.