245/348
Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
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 Switching differential of the boiler
t Time
Y Locking
signal
Depending on the consumer, the locking signal will lead to switching on / off or a set-
point reduction.
Cycling or deactivation of the pumps will reduce the amount of heat drawn from the
heat source This will considerably shorten the time required for heating up the d.h.w.
•
Heating circuit pump:
Status Effect
Locking signal = 20 %
Normal pump operation
Locking signal > 20 %
Heating circuit pump cycles
Locking signal = 93 %
Heating circuit pump OFF
•
D.h.w. pump, system pump or boiler pump:
No
effect
Through the generation of the temperature-time integral it is not only the period of time
that is considered, but also the extent of boiler temperature undershoot. This means
that when the crossing is significant, the pumps will be deactivated earlier.
Example:
TKx
23
78
Z
11
t
a
b
TK
TKw
0%
t
y
x%
c
d
e
f
SDK
y
Effect
Impact on 2-position
loads
Switching point
