Siemens SIMATIC NET OBT Operating Instructions Manual page 23

Lack of equipotential bonding
If there is no equipotential bonding in hazardous areas, there is a risk of explosion due to
equalizing current or ignition sparks.
• Ensure that equipotential bonding is available for the device.
Unprotected cable ends
There is a risk of explosion due to unprotected cable ends in hazardous areas.
• Protect unused cable ends according to IEC/EN 60079-14.
Improper installation of shielded cables
There is a risk of explosion due to equalizing currents between the hazardous area and the non-
hazardous area.
• Ground shielded cables that cross hazardous areas at one end only.
• Lay a potential equalization conductor when grounding at both ends.
Insufficient isolation of intrinsically safe and non-intrinsically safe circuits
Risk of explosion in hazardous areas
• When connecting intrinsically safe and non-intrinsically safe circuits, ensure that the
• Observe the device approvals applicable for your country.
Safety notices on use in hazardous areas
General safety notices relating to protection against explosion
EXPLOSION HAZARD
Do not connect or disconnect cables to or from the device when a flammable or combustible
atmosphere is present.
PROFIBUS Optical Bus Terminal (OBT)
Operating Instructions, 06/2022, C79000-G8976-C122-08
WARNING
WARNING
WARNING
WARNING
galvanic isolation is performed properly in compliance with local regulations (e.g. IEC
60079-14).
WARNING
Commissioning
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