166/218
Siemens Building Technologies
Basic Documentation RVA63.242, RVA53.242
CE1P2373E
Landis & Staefa Division
Description of OEM settings
26.03.2001
5.20.2 According to the boiler return temperature
Setting 1
By operating the boiler bypass pump according to the boiler return temperature’s
minimum limitation and the switching differential of the bypass pump, the boiler return
temperature can be maintained according to the return temperature acquired with
sensor B7.
When the boiler return temperature reaches the set minimum limitation (line 22
OEM
), the
boiler bypass pump will be activated. This means that hot water will be fed from the
flow directly to the return so that the boiler return temperatures rises.
When the boiler return temperature acquired with sensor B7 exceeds the set minimum
limitation (setting line 23
OEM
) by more than one switching differential of the bypass
pump (setting line 22
OEM
), the boiler bypass pump will be deactivated.
In general:
Prerequisite:
Bypass pump
TKRx < TKRmin
ON
TKRx > SDBP
OFF (on completion of the pump overrun time)
B R
B P
P N
0
1
1
0
T K R x
t
t
t
10
20
3 0 min
6 0
°C
50
4 0
3 0
min
TKRmin
SDBP
2373D04
t
BR
Burner
BP
Bypass pump
tPN
Pump overrun time
TKRx
Actual boiler return temperature
TKRmin
Minimum limitation of boiler return temperature (setting line 22
OEM
)
SDBP
Switching differential of bypass pump (setting line 23
OEM
)
Process
Reset
Example: