Siemens SIMATIC S5-100U System Manual page 517

S5-100U
C Active and Passive Faults in Automation
Equipment / Guidelines for Handling
Electrostatic Sensitive Devices
Active and Passive Faults in Automation Equipment
• Depending on the particular task for which the electronic automation equipment is used, both
active as well as passive faults can result in a dangerous situation. For example, in drive
control, an active fault is generally dangerous because it can result in an unauthorized startup of
the drive. On the other hand, a passive fault in a signalling function can result in a dangerous
operating state not being reported to the operator.
• The differentiation of the possible faults and their classification into dangerous and non-
dangerous faults, depending on the particular task, is important for all safety considerations in
respect to the product supplied.
Warning
In all cases where a fault in automation equipment can result in severe personal injury or
substantial property damage, i.e., where a dangerous fault can occur, additional external
measures, additional external measures must be taken or equipment provided to ensure
or force safe operating conditions even in the event of a fault (e.g., by means of
independent limit monitors, mechanical interlocks, etc.).
Procedures for Maintenance and Repair
If you are carrying out measurement or testing work on an active unit, you must adhere to the rules
and regulations contained in the "VGB 4.0 Accident Prevention Regulations" of the German
employers liability assurance association ("Berufsgenossenschaften"). Pay particular attention to
paragraph 8, "Permissible exceptions when working on live parts."
Do not attempt to repair an item of automation equipment. Such repairs may only be carried out by
Siemens service personnel or repair shops Siemens has authorized to carry out such
repairs.
The information in this manual is checked regularly for updating and correctness and may be modified without prior notice. The
information contained in this manual is protected by copyright. Photocopying and translation into other languages is not permitted
without express permission from Siemens.
EWA 4NEB 812 6120-02b
Active and Passive Faults in Automation Equipment/ESD Guidelines
C-1