Siemens RVA47.320 - Page 93

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Siemens Building Technologies Basic Documentation RVA47.320 CE1P2379E
HVAC Products Description of the heating engineer settings 15.07.2002
This temperature-time integral generates the locking signal for restricting the heating
circuits.
When generating the locking signal, one of four different procedures is used:
Diagram
Procedure
a to b Within a foreseeable period of time, the actual value of the boiler
temperature (TKx) will no longer be within the switching differential of
the boiler temperature setpoint.
 Locking signal will be increased
b to c and
d to e
Within a foreseeable period of time, the actual boiler temperature (TKx)
will lie within the switching differential of the boiler temperature setpoint.
 Locking signal will remain at a constant level
c to d and
e to f
Within a foreseeable period of time, the actual boiler temperature (TKx)
will lie above TKw.
 Locking signal will be decreased
f
The actual boiler temperature (TKx) exceeds the boiler temperature
setpoint.
 Locking signal will be set to 0 %.
a Start of d.h.w. heating
TK Boiler temperature
TKw Boiler temperature setpoint
TKx Actual value of the boiler temperature
SDK Boiler’s switching differential (factory setting 8K)
t Time
Y Locking signal
Temperature-time
integral
Example:
TKx
2378Z11
t
a b
TK
TKw
0%
t
y
x%
cd ef
SDK
y