STIEBEL ELTRON SOM 8 PLUS - Page 56

56
Return preheating
The return preheating function can be used for
transferring heat from a heat source to the heating
circuit return.
The allocated relay is energised when both switch-
on conditions are fullled:
• the temperature dierence between the allocated
sensors has exceeded the switch-on temperature
dierence
• the temperature at the outdoor temperature
sensor has fallen below the adjusted outdoor
temperature
With the summer switch-o option, the return pre-
heating can be suppressed outside the heating pe-
riod. If the heating circuit concerned is controlled by
the controller, the adjustments automatically adapt
to the heating circuit.
Sensor HS Relay
Sensor
Return
Adjustment chan-
nel
Description Adjustment range / selection Factory setting
Relay Relay selection system dependent system dependent
Sen. Return Return sensor selection system dependent system dependent
Sen. HS Heat source sensor selection system dependent system dependent
∆Ton Switch-on temperature dierence 2.0 ... 30.0 K [4.0 ... 60.0 °Ra] 6.0 K [12.0 °Ra]
∆To Switch-o temperature dierence 1.0 ... 29.0 K [2.0 ... 58.0 °Ra] 4.0 K [8.0 °Ra]
Summer o Summer switch-o option Yes, No No
Sensor Outdoor sensor selection system dependent system dependent*
To Switch-o temperature 10 ... 60 °C [50 ... 140 °F] 20 °C [68 °F]
Funct. Activation / Deactivation Activ., Deactivated Deactivated
Arrangement / Opt. functions / Add new function... / Ret. preheat.
* When a heating circuit has been activated, this
adjustment is determined by the corresponding
parameter in the heating circuit menu.
295931-36390-8667 SOM 8 plus_en.indb 56 20.10.2011 13:14:48