Siemens SIMATIC ET 200AL System Manual page 21

2.8 Residual risks
Despite all the technical and procedural risk reductions that have been carried out, not all
dangers can be avoided. The following sections describe these residual risks and measures to
avoid them.
2.8.1 Live parts
Electrocution on contact with live parts leads to life-threatening injuries (death).
Operation
• Do not open the module.
• Do not use damaged modules.
• Pull the plug and not the cable.
Installation and connection
• Only work on electrical parts if you are a qualified specialist (see section Target group and
personnel qualifications (Page 19)).
• Adhere to the protective measures for safe working on electrical parts (see section
Working on electrical parts (Page 20))
• Fuse the connection cables according to the current-carrying capacity of the cable used,
taking into account the applicable standards.
• Ground the module according to regulations.
• For the 24 V DC supply (SELV/PELV), only use power supply units that provide safe
electrical extra-low voltage in accordance with IEC 61131‑2 or IEC 61010‑2-201.
Maintenance
• Only work on electrical parts if you are a qualified specialist (see section Target group and
personnel qualifications (Page 19)).
• Adhere to the protective measures for safe working on electrical parts (see section
Working on electrical parts (Page 20)).
2.8.2 Conductive pollution
Electrocution during transmission of electrical energy via conductive contamination to the
body leads to life-threatening injuries (death).
• Seal unused connections with a suitable and approved sealing cap.
• Keep the module free from conductive pollution.
Distributed I/O system
System Manual, 12/2023, A5E31861578-AL
Safety instructions
2.8 Residual risks
21