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Mechanical pressure switches
S2 type series
S2 type series
Pressure switches with 2 microswitches - technical data
FEMA pressure switches of the DCM (except
DCM1000, DCM4016 and DCM4025), VCM
(except VCM4156), VNM, DNS, VNS series can
be equipped with 2 microswitches.
This is not possible with any other type
series or with Ex versions.
Technical data
Standard equipment
The standard equipment of every two-stage
pressure switch includes a switching device
with 2 microswitches, both single-pole
switching. Switch I monitors the low pressure,
switch II the higher pressure. The setting
ranges indicated in the data sheets for the
basic types apply to the two-stage pressure
switches as well. It should be noted that the
switching differentials of the individual
microswitches may not be exactly the same
due to component tolerances.
Switching difference
The switching interval of the two microswitches
is the difference (in bar or mbar) between the
switching points of the two micro switches.
Example for ZF307:
When the pressure rises (e.g. 2.8 bar), a
two-stage pressure switch turns on a warning
light, and if the pressure continues to rise (e.g.
3.2 bar) the system shuts down. The switching
interval is 3.2-2.8 = 0.4 bar. The following
applies to all versions:
The switching interval remains constant over
the whole setting range of the pressure switch.
If the switching pressure setting is changed
with the setting spindle, the switching interval
does not change - the switching points are
moved in parallel.
Switching differential
The switching differential, i.e. the hysteresis of
the individual micro switches, corresponds to
the values of the relevant basic version referred
to in the Product summary. In the case of
two-stage pressure switches, the switching
differential of the individual micro switches
is not adjustable.
Versions
Two-stage pressure switches are available in
three different versions, each identified by a ZF
number. The versions differ in terms of their
connection schemes and electrical connection
types (terminal or plug connection).
The applicable data sheet for the basic types contains the technical data for the two-stage pressure
switches. This includes all limits of use, such as temperature, maximum pressure, mounting position,
protection class, electrical data etc. The principal dimensions are the same as for single-stage
pressure switches with comparable pressure ranges and design features.
Additional Switching difference Electrical
function between the two
connection
micro switches
ZF307
Factory setting
according to
customer’s
instruction
Switching difference
fixed
Terminal
connection
(All terminals
of both
microswitches
are accessible
(6 terminals)
Connection
diagram
2 x single-pole
switching
Ordering
information required
1. Basic type with ZF 307
2. S witching points I
and II, with direction
of action in each
case (rising or falling
pressure)
Example: DCM16-307
Switching point I:
10 bar falling
Switching point II:
12 bar falling or
switching interval only.
ZF217
Adjustable
via adjustment
knobs I and II in
accordance with
"Switching
difference" table
Plug connection Example selection
in accordance with in accordance
DIN EN175301 with "Switching
(3-prong + earth schemes" table,
conductor)
page 36.
Function-
appropriate
internal wiring in
accordance with
"Switching
functions" table
1. Basic type with
ZF217
2. Switching scheme
For example:
DCM16-217/B 4
Since all values are
adjustable within the
specified limits, no
further data is required.
Note on ordering additional function ZF217
Switching scheme Switching device
A1
A
A2
C
A3
C
A4
A
B1
B
B2
D
B3
D
B4
B
C1
B
C2
D
C3
D
C4
B
D1
A
D2
C
D3
C
D4
A
Ordering position
DCM6-217A-S
DCM6-217C-S
DCM6-217C-S
DCM6-217A-S
DCM6-217B-S
DCM6-217D-S
DCM6-217D-S
DCM6-217B-S
DCM6-217B-S
DCM6-217D-S
DCM6-217D-S
DCM6-217B-S
DCM6-217A-S
DCM6-217C-S
DCM6-217C-S
DCM6-217A-S
Additional text
Switching scheme A1
Switching scheme A2
Switching scheme A3
Switching scheme A4
Switching scheme B1
Switching scheme B2
Switching scheme B3
Switching scheme B4
Switching scheme C1
Switching scheme C2
Switching scheme C3
Switching scheme C4
Switching scheme D1
Switching scheme D2
Switching scheme D3
Switching scheme D4