Siemens S7-400 Installation Manual page 41

The figure below shows how much space you must allow for when assembling an
S7-400 from two racks with a cable duct or fan subassembly. This requirement is
increased by a height of 400 mm for each additional rack with a cable duct or fan
subassembly.
Mounting depth, fitted: max. 237 mm
Note
A minimum clearance as shown in the above figure between rack and cable duct
or fan subassembly must not be provided, but is essential between two adjacent
racks and between racks and other equipment.
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04
1 2 3 4 5 6
Cable duct/fan subassembly
840 mm
1 2 3 4 5 6
Cable duct/fan subassembly
7 8 9 10 11 12 13 14 15 16 17 18
7 8 9 10 11 12 13 14 15 16 17 18
19-inch reference level
Installing the S7-400
2-15