KROHNE VA 40 ATEX II2G Ex i EN - Manual (Page 11)

ELECTRICAL CONNECTIONS
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VA40
www.krohne.com 06/2013 - 4002262402 - MA VA40-Ex-II2G-AD R02 en
Electrical connections
4.1 General notes
The separate intrinsically safe signal circuits of protection level "ia" or "ib" are electrically
connected in the terminal compartment of the plug housing for the limit switch type TG21 and
MS14. The limit switch MS14 ist connected to the strandes wires. The terminal housing must
have a protection class of min. IP20. Take note of the polarities given for the limit switch TG21.
Connecting cable
The connecting cables must be selected according to prevailing installation standards (e.g.
EN 60079-14).. The outer diameter of the connecting cable must be within the sealing range of
the cable entry. The connecting cables must be fixed and laid in such a way as to be sufficiently
protected against damage.
All cores that are not used must be securely connected to the ground potential of the hazardous
area or carefully insulated against each other and against ground (test voltage ≥ 500 V
eff
).
4.2 Grounding and equipotential bonding
If the device is not sufficiently electrostatically grounded via the process cables, an additional
earth connection must be established using the ground terminal. The location of the ground
connection on the back rail is shown below. This connection only ensures electrostatic
grounding of the device and does not meet the requirements for equipotential bonding.
Grounding connection 1
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