Siemens S7-400 Installation Manual page 256

Assembling and Installing Systems
Protection Against Other Electrical Effects
The following table shows the other external effects against which you must
provide protection.
Protection against ...
inadvertent actuation of
operator controls
splashing and surging water suitable protective devices or installation in waterproof
direct solar radiation
mechanical damage
A-4
... by Means of ...
a suitable arrangement or covering of keyboard and
operator controls or a recessed arrangement of operator
controls.
housings.
suitable shading or installation in appropriately sheltered
locations.
suitable demarcation, protective devices, or installation in
rugged housings.
S7-400 and M7-400 Programmable Controllers Hardware and Installation
A5E00069481-04