57/118
Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
13 Function block "Setpoint of return temperature limitation"
20.05.2008
13.3.3 Mode of operation with a single device (with no bus)
252
4B
03e
Controller 1
Boiler controller
Controller 2
Plant type 1-1
Controller 2 generates a critical locking
signal which shuts the heating circuit
mixing valve and deactivates the
charging pump
With no possibility of minimum
return temperature limitation
Operating line 101 = 50 °C
return temperature sensor
connected
13.3.4 Mode of operation in interconnected plants
Controller 1
Plant type 5-0
Controller 2
Plant type 1-0
Controller 3
Plant type 1-1
Critical locking signal
Controller 2 shuts the
heating circuit mixing
valve
Controller 3 shuts the heating
circuit mixing valve and deacti-
vates the d.h.w. charging pump
LPB
25
24B0
7
e
Setting operating
line101 = 50 °C,
return sensor connected
Setting operating line 101 = - - - , no own
return sensor connected
Setting operating line 101 = - - - , no own
return sensor connected
Critical locking signal
Controller 1
Boiler controller
Controller 2
Plant type 1-0
Controller 3
Plant type 1-0
Return temperature signal
Controller 2 limits the
return temperature
to 50 °C min.
LPB
25
41
0
2en
Setting operating line 101 = 50 °C,
return sensor connected
Setting operating line 101 = 40 °C, on own
return sensor connected
(With no possibility of
minimum limitation of
the return temperature)
Controller 3 limits the
return temperature
to 40 °C min.
The zone controller with its own return temperature sensor (plant type 1–x) passes the
return temperature to the other zone controllers in the same segment, which can provide
minimum limitation of the return temperature on a local basis, depending on the settings
made. This means they generate a critical locking signal internally. For response to criti-
cal locking signals, refer to section “25.4.7 Gain of locking signal“.
Central action of
limitation
Local action of
limitation
