Installing the S7-400

Mounting Screws

You have a choice of the following types of screw for securing a rack:

Screw Type

Explanation

 

 

M6 cylinder-head screw to

Choose the screw length according to your

ISO 1207/ISO 1580 (DIN 84/DIN 85)

assembly.

 

You also need “6.4” washers to ISO 7092

M6 hex. screw to ISO 4017 (DIN 4017)

(DIN 433).

 

 

 

Step 3: Connecting the Rack to the Chassis Ground

Connect the rack to the chassis ground. A threaded bolt is provided for this purpose on the bottom left of the rack.

Minimum cross-section of the conductor to the chassis ground: 10 mm2.

If the S7-400 is mounted on a mobile rack, you must provide a flexible conductor to the chassis ground.

Note

Always ensure that there is a low-impedance connection to the chassis ground (see the figure below). You achieve this with the shortest possible, low-resistance conductor with a large surface to establish large-area contact.

M6 threaded bolt

Contact washer

Terminal

Plain washer

M6 nut

To chassis ground

Automation System S7-400

Hardware and Installation

2-13

A5E00850741-01

 

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Image 29
Siemens S7-400 installation manual Mounting Screws, Connecting the Rack to the Chassis Ground, Screw Type Explanation