Fema DCM Series, Assembly And Operating Instructions Manual, Page: 40 / 96

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5. Two stage pressure switches …307, …217
A switch unit with two microswitches both with
single-poled changeover, forms part of the
basic equipment for each two-stage pressure
switch. The first switch I monitors lower pres-
sure, the second switch II monitors higher
pressure. It should be noted that the switching
differentials of the individual microswitches
cannot be exactly identical because of their
component tolerances.
The switching interval of both microswitches
is the interval (in bar or mbar) between the
switching points of both microswitches. Applies for all variations:
Changes to the setting spindle, to the setting of
switching pressure, do not lead to changes in
the switching intervals as the switching points
are adjusted correspondingly.
The switching differential of the individual
microswitches corresponds to the switching
differences listed under basic equipment.
The switching differential cannot be set for
individual microswitches in two-stage
pressure switches.
5.1 Model …307
The switching interval between both switches
is set according to the customer’s require-
ments. With increasing pressure is firstly
I microswitch
(terminal
connection 1–3)
and then
II microswitch
(terminal
connection 4–6)
activated.
The switching points can moved parallely to
the setting spindle.
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