Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
12 Technical documentation
83309302 1/2018-05 La
151-196
12.2.4 Weather compensated/Room control
The flow temperature of the heating circuit is controlled depending on the external
temperature and the room temperature.
An external sensor and room device or room sensor are required for weather com-
pensated control and room temperature dependent control.
Mount the external sensor to the north side or the north-west side of the build-
ing, half way up (min 2,5 m).
Avoid direct solar radiation at the external sensor and room sensor.
Avoid heat up by external heat sources.
The current flow temperature setpoint is calculated from:
external temperature,
Heating curve:
Gradient
,
Parallel movement
,
room setpoint temperature,
current room temperature,
room sensor influence.
The heating curve and the room setpoint temperature can be set in the user level
[ch. 6.5.3].
The room sensor influence can be set in the Engineer level [ch. 6.6.5.2].
12.2.5 De-couple control
The appliance modulates the capacity in heating mode based on the de-couple
temperature.
With this control option, the pump modulates between the de-couple sensor B2
and the flow sensor depending on the differential temperature. The function can be
adapted to the conditions of the system using parameter
5.2.2 Temperature
differential flow/de-couple pump
DHW loading can be achieved via a three-way valve upstream of the hydraulic de-
couple, as control in DHW mode reacts to the internal flow sensor or de-couple
sensor B2 (depending on hydraulic version).
Connect de-couple sensor to input B2 [ch. 5.7.1].
Switch-on criteria
B2 < flow setpoint
Switch-off criteria
B2 > flow se temperature differential