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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
Residual heat function
4.118 Maximum duration of the residual heat
function
•
Use of the residual heat in the wood-fired boiler
•
The maximum duration of the residual heat function can be limited
The residual heat function makes use of the residual heat stored in the boiler mass af-
ter the flame has extinguished.
To set the maximum duration of the residual heat function, press the + / - buttons.
Setting range
Unit
Factory setting
--- / 5...60
min
15
The residual heat function will be activated only when, previously, the pump of the
wood-fired boiler has been in operation for at least 30 minutes. The function is acti-
vated only once.
To activate the residual heat function several times, select setting 1 on operating line
386 (multiple execution of residual heat function).
– – –
Residual heat function OFF
The maximum duration of the residual heat function commences when the pump over-
run time has elapsed (operating line 372).
If
no residual heat function
is selected, the pump will be deactivated on completion of
the pump overrun time.
If the
residual heat function is selected,
the valve for the maintained boiler return
temperature (if present) will assume the “throughport” position (no water from the flow
added to the return). The boiler pump continues to run. The residual heat in the boiler is
thus carried away. This plant state is maintained for a
minimum of 2 minutes
.
Then, the pump continues to run and the valve maintains that position until either the
“Maximum duration of the residual heat function” has elapsed or until the temperature
differential (
Δ
T) between boiler temperature and return temperature sensor (B22 - B72)
has dropped below 4 Kelvin.
When one of these
criteria
is satisfied, the pump will be activated and the valve as-
sumes the "angle" position. The wood-fired boiler is thus hydraulically decoupled from
the rest of the plant.
The temperature differential between boiler temperature and return temperature sensor
may then start to increase again. If desired, this residual heat can be utilized by repeat-
edly activating the residual heat function (operating line 386).
Benefit
Description
Setting
Important
Special displays
Effect
Note
