Benefit
Description
Setting
Effect
Example
154/218
Siemens Building Technologies
Landis & Staefa Division
5.7 Pump overrun time
Protects the boiler against overtemperatures.
Overrun of the pumps makes certain that residual heat will be carried away, thus
preventing the manual safety limit thermostat from responding.
Setting range
0...20
All pumps that - at the time of burner shut-down - were operating, continue to run for
the period of time set here. The behavior is the same as with burner shut-down when,
with the burner deactivated, the boiler temperature demand becomes invalid. Also, the
previous flow temperature setpoint is maintained to make certain the mixing valve will
be open during the same period of time.
HK
BR
ON
OFF
Q
ON
OFF
Y
TVNw
TVRw
HK
Operating mode
Q
Pumps
Y
Mixing valve
TVNw
Nominal flow temperature setpoint
TVRw
Reduced flow temperature setpoint
tPN
Pump overrun time
Nominal operation
Reduced operation
Basic Documentation RVA63.242, RVA53.242
Description of OEM settings
Unit
min
tPN
Factory setting
5
t
t
t
t
CE1P2373E
26.03.2001