Siemens S7-400 installation manual Filtering the 24 VDC Supply, Insulation Monitoring

Wiring the S7-400

Filtering the 24 VDC Supply

When you power the S7-400 from a battery with the ungrounded configuration, you must provide interference suppression for the 24 VDC supply. Use a Siemens power cable filter, such as the B84102-K40.

Insulation Monitoring

If a double fault could cause a hazardous state in the installation, you must provide insulation monitoring.

Example of Ungrounded Operation

If you have configured an S7-400 with a local connection and you only wish to ground the overall installation at the CR, you can operate the ERs in an ungrounded configuration.

Note

If you connect an ER via a local connection with 5 V transfer, ungrounded operation is mandatory for the ER.

Automation System S7-400	Hardware and Installation	4-9
A5E00850741-01