Siemens SIMATIC S5-95F, Руководство пользователя

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S5-95F Guidelines for the Planning and Installation of the Product
Please observe the following points when connecting the shield:
• Use metal cable clamps for securing the braided shield. The clamps must enclose the shield
over a large area and provide a good contact (see Figure 3-4).
• Connect the shield to a shield bar immediately after the cable entry into the cabinet. Route the
shield as far as the module but do not connect it there again.
Figure 3-4. Examples of Securing Shielded Lines with Cable Clamps
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3.4.4 Special Measures for Interference-Free Operation
Fitting Quenching Elements to Inductances
As a rule, inductances such as contactor or relay coils controlled by SIMATIC S5 do not require
external quenching elements in the circuit, because the quenching elements are already integrated
in the modules.
Inductances should be fitted with quenching elements only
• If SIMATIC S5 output circuits can be switched off by additionally fitted contacts, such as relay
contacts for EMERGENCY OFF. In this case the integrated quenching elements in the modules
are no longer effective;
• If they are
not controlled by SIMATIC S5 modules.
You can place freewheel diodes, varistors or RC networks in circuit with inductances.
Figure 3-5. Quenching Circuits for Inductances
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With diode
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With Zener diode
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With varistor
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With RC network
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Circuitry for DC-operated inductances
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Circuitry for AC-operated inductances
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EWA 4NEB 812 6210-02
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