36• The WAGO-I/O-SYSTEM 750

Shielding (screening)

2.8 Shielding (screening)

2.8.1 General

The shielding of the data and signal conductors reduces the electromagnetic influences thereby increasing the signal quality. Measurement errors, data transmission errors and even disturbances caused by overvoltage can thus be avoided.

Attention

Constant shielding is absolutely required in order to ensure the technical specifications in terms of the measurement accuracy.

The data and signal conductors should be laid separately from all highvoltage cables.

The cable shield is to be laid over a large-scale surface onto the earth potential. With this, incoming disturbances can be easily diverted.

The shielding should be placed over the entrance of the cabinet or housing in order to already repel disturbances at the entrance.

2.8.2 Bus Conductors

The shielding of the bus conductor is described in the relevant assembly guideline of the bus system.

2.8.3 Signal Conductors

The bus terminals for analogue signals as well as some interface bus terminals possess connection terminals for the shield.

Note

Improved shielding can be achieved if the shield is previously placed over a large-scale surface. For this, we recommend the use of the WAGO shield connecting system for example.

This is particularly recommendable for systems with large-scale expansions where it cannot be ruled out that differential currents are flowing or high pulse currents, i. e. activated by atmospheric discharge, may appear.

WAGO-I/O-SYSTEM 750

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