Mode Of Operation With A Single Device (With No Bus); Mode Of Operation In Interconnected Plants - Siemens RVL481 Basic Documentation

Central action of
limitation
Local action of
limitation
Siemens
Building Technologies

13.3.3 Mode of operation with a single device (with no bus)

Controller 1
Boiler controller
With no possibility of minimum
return temperature limitation

13.3.4 Mode of operation in interconnected plants

LPB
Controller 1
Plant type 5-0
Setting operating
line101 = 50 °C,
return sensor connected
Critical locking signal
LPB
Controller 1
Boiler controller
(With no possibility of
minimum limitation of
the return temperature)
Return temperature signal
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".
Heating and D.h.w. Controller RVL481
13 Function block "Setpoint of return temperature limitation"
Controller 2
Plant type 1-1
Operating line 101 = 50 °C
return temperature sensor
connected
Critical locking signal
Controller 2
Plant type 1-0
Setting operating line 101 = - - - , no own
return sensor connected
Controller 3
Plant type 1-1
Setting operating line 101 = - - - , no own
return sensor connected
Controller 2
Plant type 1-0
Setting operating line 101 = 50 °C,
return sensor connected
Controller 3
Plant type 1-0
Setting operating line 101 = 40 °C, on own
return sensor connected
Controller 2 generates a critical locking
signal which shuts the heating circuit
mixing valve and deactivates the
charging pump
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
Controller 2 limits the
return temperature
to 50 °C min.
Controller 3 limits the
return temperature
to 40 °C min.
CE1P2541en
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20.05.2008