Hitachi YUTAKI Series - Tariff Switch (Heat Pump Blocking) Input

Controller pack
Service Manual
94
Heatpump control functions
SMGB0066 rev.0 - 12/2009

P14 / EP14 Heat Pump minimum outdoor temperature (default -20°C)
EP28 Heat Pump minimum supply temperature below outdoor temperature of EP32 (default 35°C)
EP29 Heat Pump maximum supply temperature above outdoor temperature of EP34 (default 55°C)
EP32 HeatPumpminimumsupplyinexionpoint(default0°C)
EP33 Heat Pump maximum supply temperature below outdoor temperature of EP34 (default 50°C)
EP34 Heat Pump maximum supply changing point (default -10°C)
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note
Engineering Parameters (EP) are only available for service engineers. -
 

The tariff switch input (heat pump blocking) is only allowed for Bi-Valent systems. For mono-valent or mono-energetic
systems the heat pump can never be blocked by this input.

This function allows an external tariff-switch device to switch off the heat pump during times of peak electricity demand.
Whenthecontrollerisworkinginbi-valentmode,theboilerwillbeswitchedontoprovidethenecessaryheating.

P24 CongurationofTariff/TimerInput(default4)
  
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 DWH time clock
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note
The tariff/timer input can be used for DHW time switching OR Heat Pump blocking, not both. -