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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.208 Maximum forward shift of optimum start
control
•
Limitation of optimum start control
The forward shift of optimum start control can be limited to a maximum.
Setting range
Unit
Factory setting
00:00...06:00 hh:mm
00:00
The adjusted value will automatically be displayed on this operating line.
00:00 Optimum start control is switched off.
00:10 - Maximum forward shift of optimum start control
06:00 Optimum start control acts with or without room sensor.
The maximum forward shift can be set with parameter “Maximum forward shift
with optimum start control” (range is 0…6 h). This parameter can also be used
to switch optimum start / stop control off (setting = 0).
During non-occupancy hours, the heating is maintained at the reduced level. Towards
the end of the setback period, optimization switches the control back to the nominal
temperature level.
Optimization calculates the changeover time such that, at the start of occupancy, the
room temperature will have reached the nominal setpoint.
The forward shift is made with energy occupancy period.
4.208.1 Without room temperature sensor
The composite outside temperature is used as the compensating variable. In the case
of floor heating systems, the maximum forward shift should be longer than with radiator
systems. Using parameter KON, the forward shift can be matched to the building dy-
namics.
t
E
[min] = (12°C - TAgem) * KON * 1/16 * 10 [min]
Forward shift tE in hours and minutes with optimum start control without room sensor:
TAgem KON
0 4 8 12 16 20
-
20
0 1h20 2h40 4h00 5h20 6h00
-
10
0 0h50 1h50 2h40 3h40 4h30
0
0 0h30 1h00 1h30 2h00 2h30
+
10
0
0 0h10 0h10 0h20 0h20
tE
TAgem
Composite outside temperature
tE Forward
shift
KON
Parameter for quick setback and optimum start control (KON)
without room sensor (operating line 702
EXP
)
Parameter KON:
KON = 0:
Function deactivated
Note:
KON also acts on quick setback
Small KON:
For buildings that can be heated up quickly
Large KON:
For buildings that can be heated up slowly
Benefit
Description
Setting
Effect