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Siemens
Basic Documentation RVP360
CE1P2546en
Building Technologies
15 Function block: Multifunctional relay
2017-07-24
15.2.2 Relay energized in the event of fault
If the controller receives an error message from itself or via data bus (LCD shows
Er
), the multifunctional relay is energized. This takes place with a delay of 2
minutes. When the error is corrected, that is, when the error message is no longer
present, the relay is deenergized with no delay.
15.2.3 Relay energized when there is demand for heat
If the controller’s own heating circuit or the d.h.w. circuit calls for heat, the multi-
functional relay is energized.
In interconnected plants, the relay is also energized when the controller receives
a demand for heat from the system.
15.2.4 Circulating pump
Operating line 141 can be used to enter the scheduler program according to which
the d.h.w. circulating pump shall operate. The use of a circulating pump is optional
with all types of plant.
The circulating pump runs only when d.h.w. heating is on (button
is lit).
The circulating pump runs at the following times, depending on the setting made on
operating line 141:
Operating line 141 The circulating pump runs …
3
continuously (24 hours a day)
4
according to one or several heating programs
5
according to scheduler program 2 of controller
With setting 4, operation of the circulating pump depends on the setting made on
operating line 121 (provided the controller has communication capability and oper-
ates in an interconnected plant). In an interconnected plant with several controllers,
that is, with several heating programs, the circulating pump runs when at least one
of the controllers involved provides heating to the NORMAL temperature according
to its heating program (independent of operating mode) and does not operate in
holiday mode.
The circulating pump operates with a forward shift against the times of the heating
program; this means that optimized switching on has an impact.
The behavior of the circulating pump is shown on the basis of 2 examples where
controllers A and B are interconnected via data bus:
Op. line
121
Op. line
141
Controller
(heating
circuit)
Operating
mode
Heating pro-
gram, holidays
Circulating
pump
2
4
A (HC1)
06:00...18:00
Circulating
pump runs
from 06:00
to 23:00
A (HC2)
03:00...22:00, holi-
days
B (HC1)
07:00...22:00
B(HC2)
07:00...23:00
General mode
of operation
Example 1