OEG KSF-Pro Handbuch Seite 61

Operation diagram for hydraulic schemes with two heat sources:
temperature
2
1
1 2
LEGEND:
A - liquid fuel boiler (heat source A)
B - solid fuel boiler or heat accumulator (heat source B)
PT - switchover temperature
Switch-over from liquid (A) to solid (B) fuel boiler or to heat accumulator
When the heat source B temperature exceeds the switchover temperature PT (point 1), the
heat source A is switched off.
Switchover temperature PT is the highest temperature of listed below:
- minimum temperature of heat source B, increased for 10 °C,
- highest calculated stand-pipe temperature for the mixing circuit 1 or 2 (upper limit of this
temperature is 5 K lower as set with parameter S5.12),
- measured d. h. w. temperature, increased for 10 °C (upper limit of this temperature is set
with parameter S4.8).
When the heat source B temperature aproaches to heat source A temperature, the
switchover valve turns to the heat source B (point 2).
Switch-over from solid fuel boiler or heat accumulator (B) to liquid fuel boiler (A)
If the heat source B temperature drops below switchover temperature PT (point 3) and
heating demand cannot be covered anymore, the countdown to activate heat source A is
started. Bigger difference between required temperature and actual temperature of heat
source B results in earlier activation of heat source A. Smaller difference between required
temperature and temperature of heat source B results in later activation of heat source A.
After the countdown, the heat source A is switched on again (point 4).
When the heat source A temperature exceeds the heat source B temperature for 6 °C, the
switchover valve turns to the heat source A (point 5).
3
4
delay to start
source A
3 4
61
PT
5
time
5
Service setting manual
A
B