Som 9s – STIEBEL ELTRON SOM 9s User Manual

Page 85

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SOM 9s

LLOGI/DTOVR

Adjustment range: 0.0 ... 40.0 °R

Factory setting: 10 °R

note:
The overrun function is only available, if both
Grundfos sensors (VFS and RPS) are used.

The system cooling function aims to keep the solar system

operational for a longer time. The function overrides the

maximum tank temperature to provide thermal relief of

the collector field and the heat transfer fluid on hot days.
If the tank temperature is higher than the adjusted maximum

tank temperature and the switch-on temperature difference

DTCO is reached, the solar system remains activated or

is switched on. Solar loading is continued until either the

temperature difference falls below the adjusted value DTCF

or the collector emergency shutdown temperature CeM

is reached.
If the system cooling function is active, is shown on the

display (flashing).

System cooling

CooL / OSYC

System cooling option
Adjustment range: ON / OFF
Factory setting: OFF

COOL / DTCO

Switch-on temperature diff.
Adjustment range: 2.0 ... 60.0 °R
Factory setting: 40.0 °R

COOl / DTCF

Switch-off temperature diff.
Adjustment range: 1.0 ... 59.0 °R
Factory setting: 30.0 °R

note:
This function will only be available if the collec-

tor cooling function, the heat dump function, and

the drainback option are deactivated.

Tank cooling

When the tank cooling function is activated, the controller

aims to cool down the tank during the night in order to

prepare it for solar loading on the following day.
If the adjusted maximum tank temperature (S MAX /

S1MAX / S2MAX) is exceeded and the collector tempe-

rature falls below the tank temperature, the system will be

reactivated in order to cool down the tank.
Reference temperature differences are DT O and DT F.

COOl / OSTC

Option tank cooling
Adjustment range: ON / OFF
Factory setting: OFF

note:
If the temperature at the tank sensor reaches

200 °F, all cooling functions will be blocked. The

switch-on hysteresis is 10 °R.

Cooling functions

Different cooling functions can be activated: system cooling,

tank cooling and heat dump.

COOl / OTCL

Overtemperature collector
Adjustment range: 150 ... 320 °F
Factory setting: 230 °F

Heat dump

COOL / OHDP

Heat dump function
Selection: ON / OFF
Factory setting: OFF

If the heat dump function OHDP is activated, the selected
relay is energized with 100%, if the collector temperature
reaches the adjusted collector overtemperature OTCL.
If the collector temperature falls by 10 °R below the adju-
sted collector overtemperature OTCL, the relay will be
switched off.
A selection can be made between pump logic and valve logic
(OTPUM On = pump logic, OTPUM OFF = valve logic).
If pump logic is selected, the relay for solar loading switches
off and the relay for heat dump remains switched on.
The relay for the heat dump function can be selected in the
HDReL channel.

note:
The adjustable value OTCL is locked against
the collector emergency temperature CeM
by 20 °R. The heat dump will only be available
if the collector cooling function, the system
cooling function, and the drainback option are
deactivated.

COOL / OTPUM

Pump or valve logic
Selection: ON / OFF
Factory setting: OFF

COOL / HDREL

Relay heat dump function
Selection: system dependent
Factory setting: 3