Siemens 7MB2041, Руководство по эксплуатации, Страница: 31 / 152

Installing and connecting
3.4 Electric connection
OXYMAT 64
Operating Instructions, 06/2008, A5E00880383-03
29
● The RC element should therefore be dimensioned according to the following rule of
thumb:
R [ Ω ] ≈ 0.2 x R
L
[ Ω ]
C [μF] ≈ I
L
[ A ].
Also make sure that a non-polarized capacitor C is used.
In the case of operation with direct current, a spark-quenching diode can be fitted instead
of the RC element.
● The connection lines must be shielded to the relay outputs, the binary inputs, the analog
inputs and the analog output. Connect these to the corresponding trapezoidal plugs
(SUB-D plug connectors) in accordance with the routing assignments.
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0
0
Figure 3-3 Example of spark suppression on a relay contact
● The reference ground of the analog inputs is the potential of the housing.
● The analog output is floating.
● The shielding of the interface line must be at the potential of the housing. Connect the
shield of the line to the shield of the SUB-D plug connector with a high contact area. The
core cross-section must be ≥ 0.5 mm². The interface line may be at most 500 m long.
Note
All connection lines (except for the mains connection line) must be shielded. The
shielding of the connected lines must have a large-area and continuous contact at the
respective screw couplings. The core cross-section must be ≥ 0.5 mm². We recommend
cables of type JE-LiYCY...BD. The cable length of the analog output depends on the
load.