Appendix   
A.1 ESD Directives 
  OP 73micro, TP 177micro (WinCC flexible) 
150  Operating Instructions, 09/2007, 6AV6691-1DF01-0AB0 
Electrostatic charge 
 
CAUTION 
 
Electrostatic charge 
ESDs may be destroyed by voltages well below the perception threshold of persons 
Voltages of this kind develop when a component or an assembly is touched by a person 
who is not grounded against static electricity. Usually, it is unlikely that damage to an ESD 
as a result of overvoltage is detected immediately but may become apparent only after a 
longer period of operation. 
Prevent electrostatic charge of your body before you touch the ESD! 
 
Anyone who is not connected to the electrical potential of their surroundings is subjected to 
electrostatic charge. 
The figure indicates the maximum electrostatic charge anyone is subjected to when 
contacting the materials shown. These values correspond with specifications to IEC 801-2. 
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Figure A-2  Electrostatic voltages with which a person can be charged. 
①  Synthetic materials 
②  Wool 
③  Antistatic materials such as wood or concrete