Siemens Simatic CFU Commissioning Manual page 26

Operation planning
5.4 Use in hazardous areas
Requirements for connecting and disconnecting non-intrinsically safe power circuits:
● The atmosphere is not explosive.
● You have ensured that the CFU is de-energized.
Sealing the enclosure
Explosion hazard
Cable glands ensure sealing between the cables and the enclosure.
Make sure that strain relief is available for all cables before they are inserted into the enclosure.
● Only permanently installed cables and lines may be inserted.
● Strain on the CFU cable glands can affect the degree of protection and is not permitted.
● Cable glands do not serve as strain relief.
Equipment protection type
The device protection type is only guaranteed if the enclosure is closed.
● The cover must be mounted; the required cable glands must be mounted and tightened.
● Unused openings for cable glands must be closed.
Seal protection
Contamination or cable residues may lead to malfunctions or short circuits. Before mounting,
check the enclosure, the seals on the cover, the cable glands, the screw plugs and the
pressure compensation element.
● Ensure that all components are undamaged and clean.
● Ensure that all components are correctly seated before and after mounting.
● Tighten screws and cable glands to the correct tightening torque.
The SIMATIC CFU PA bundle with aluminum enclosure contains cable glands. If you want to
use the SIMATIC CFU PA bundle with aluminum enclosure, you must observe the cable cross-
sections.
You can find additional information in section "Technical specifications of the SIMATIC CFU
PA bundle with aluminum enclosure (Page 143)".
● For cable inlets with Ex tc protection class, make sure that the seals are approved for the
temperature range used.
● It is possible to install specially certified cable and conductor glands, as well as blanking
and sealing plugs.
26
DANGER
The operator must ensure appropriate strain relief.
CAUTION
CAUTION
Commissioning Manual, 07/2018, A5E39252870-AC
SIMATIC CFU