Siemens Simatic CFU - Page 31

Labeling of the CFU
The CFU is equipped with markings for the explosion-prone area. These markings indicate in
which explosion-prone environments the equipment can be used.
Certificates for the CFU
The EU prototype test certificate and the EU certificates of conformity for the CFU are available
under Service & Support on the Internet (
https://support.industry.siemens.com/cs/us/en/).
Connecting and disconnecting the cables to the CFU during operation
DANGER
Explosion hazard
It is forbidden to open the housing during operation in the Zone 22 hazardous area.
De-energize the CFU before carrying out any work on it.
DANGER
Explosion hazard
In the Zone 2 hazardous area, it is forbidden to connect or disconnect the following cables to/
from a CFU during operation:
● Power supply
● PROFINET cable (BusAdapter)
● Cable to freely configurable channels
De-energize the CFU before carrying out work on these cables.
Hazardous area - zone 2:
In a CFU PA, fieldbus connections are implemented as intrinsically-safe connections (Ex ic)
and may be inserted or removed during operation.
Requirements for connecting and disconnecting non-intrinsically safe power circuits:
● The atmosphere is not explosive.
● You have ensured that the CFU is de-energized.
Operation planning
4.9 Use in hazardous areas
SIMATIC CFU
Commissioning Manual, 08/2019, A5E39252870-AD 31