Wilo DDA Einbau- Und Betriebsanleitung Seite 23

5.1.3 DDM differential pressure contact manometer
yellow flag
I
II
IV
5.1.4 DDG differential pressure sensor
Installation and operating instructions Wilo-DDA/-DDS/-DDM/-DDG
With ∆p ≥ set value: Contact closed,
act
with ∆p < set value: Contact open.
act
The DDM is a 3-point controller for universal evalu-
ation of the differential pressure with the option to
output 2 switching signals. They provide information
about the range in which the differential pressure is
located. The switch-over points can be configured
on the DDM. The tappet of the diaphragm actuates
two differently positioned micro switches for higher
or lower speed ranges. The switches are designed as
normally open contacts.
The switching threshold ∆p
ton of the DDM (Fig. 3, item 1) for switching to
higher speed ranges.
If ∆p < ∆p , contact I, IV is closed. The switching
act min
threshold ∆p is set on the right button (Fig. 3,
max
item 2) for switching to lower speed ranges.
If ∆p > ∆p , contact I, II is closed.
act max
∆p < ∆p < ∆p
min act
Wire no.
1
2
2
→Fig. 4/5
The DDG is used as a signal transmitter for the Wilo
control devices (variable speed control).
The resistance measuring bridge of a ceramic sensor
is set on the left but-
min
: both contacts are open.
max
en
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