Dead Zone - Theben KNX Series Handbook

6.8 Dead zone

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The dead zone is a buffer area between heating and cooling mode.
Within this dead zone, neither heating nor cooling occurs.
Without this buffer area, the system would permanently switch between heating and cooling. As
soon as the set point was fallen below, the heating would be activated. After hardly reaching the
set point, the cooling would immediately start, the temperature would fall below the set point
and switch on the heating again.
Depending on the type of control, the dead zone can be extended by the value of the hysteresis.
Case 1: Heating and cooling with continuous control
Cooling set point 24ºC
Heating set point 20 °C
The dead zone (4 K) is not affected.
Case 2: Heating with 2-point control and cooling with continuous control
Cooling set point 25 ºC
Heating set point 20 °C
The dead zone (4 K) is increased by the value of the hysteresis (1K) and offsets the cooling set
point value to 25 °C.
Case 3: Heating with 2-point control and cooling with continuous control
Cooling set point 25 ºC
Heating set point 20 °C
The dead zone (4 K) is increased by the value of the hysteresis (1K) and offsets the cooling set
point value to 25 °C.
RAMSES 718 P / RAMSES 718 S
DEAD ZONE 4 K
DEAD ZONE 4 K
Heating hysteresis 1 K
Cooling hysteresis 1 K
DEAD ZONE 4 K
Appendix
97