Som 7 si, Orec, Dt o – STIEBEL ELTRON SOM 7 SI User Manual

Page 21: Dt f

SOM 7 SI

4.2 Recommended Settings for any System Scheme

Below is a list of important settings which must be changed from their default value no matter what system

scheme (Arr. 1 - Arr. 9) is being used. Any time the system scheme is changed these values need to be

reset to the below values. If this is not done there is a very good chance that the system will overheat and

thus be in need of time consuming and possibly costly repairs.

Display

Code

Parameter Name

and Reference

Recommended Setting and Explanation

(All temperatures in °F)

Collector Emergency

Shutdown Temperature

(p. 18)

310° This prevents the HX fluid directly behind that in the
sensor well from causing the system to go into emergency
shutdown mode as soon as the cooling function is activated.

OCX

System Cooling
Function (p. 18)

On Failure to change this option to ‘on’ will likely result in
overheating of the system at some point.

CMX

Maximum Collector

Temperature (p. 18)

230° Having a relatively large

ΔT between CMX and EM

prevents the HX fluid directly behind that in the sensor well
from causing the system to go into emergency shutdown mode
as soon as the cooling function is activated.

OREC

Recooling Function

(p. 19)

On This prevents a cumulative overheating of the system by
ensuring a relatively high

Δt between the tank temperature and

and the security switch-off of the tank (205°).

Below is a list of the recommended switch-on and switch-off settings for the controller. These options are

available on all 9 system schemes. These settings also need to be reset to the below values whenever the

system scheme (Arr. 1 - Arr. 9) is changed. Advanced users may want to set these differently depending on

the circumstances.

Display

Code

Parameter Name

and Reference

Recommended Setting and Explanation

(All temperatures in °F)

DT O

Switch on Temperature

Difference (p. 17)

15° Setting this too low can cause the circulator to cycle on and
off too frequently.

DT F

Switch off Temperature

Difference (p. 17)

5° Too high of a

ΔT between DT O and DT F can cause the

circulator to switch on and off too frequently.