Heating Circuit Outside Temperature Assignment; Outside Temperature Emergency Operation Value - Honeywell SDC Service Manual

SDC / DHC
6.8.2
NOTE
Function
See also
6.8.3
Function
EN2H-0221GE51 R0812

Heating circuit outside temperature assignment

Function active only when using a second outside sensor!
If in the central device a second outdoor sensor (AF2) was
connected to a variable input and registered, the heating circuit
can be assigned either to the outside sensor 1, 2 or to the mean
value of both sensors.
For each outside sensor the following applies:
In case of a defect affecting a sensor, switching to the remaining
outside sensor with simultaneous fault indication occurs
automatically. In case of a defect affecting both sensor circuits the
heating circuit is regulated on the basis of a set heating
characteristic curve and heating program corresponding to a
fictitious outside temperature of 0°C with regard to the set
minimum temperature.
5.2.5 "Direct Heating Circuit" / "Mixed Heating Circuit 1" / "Mixed
Heating Circuit 2" menu, Pg. 78

Outside temperature emergency operation value

If a connected outside sensor fails during weather condition-
controlled operation (sensor short-circuit or interruption),
emergency operation takes effect.
Weather condition-based control then adjusts the temperature
based on an assumed fixed outside temperature specified via a
parameter value.
Designation
Characteristic curve for
emergency operation without
outside sensor
Control Functions
Key/Menu Parameter
SYSTEM 29
121