303049 / 825060300230
2022-05-30·BA00·III·en·00
Mounting and Installation
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Ex d enclosure made of aluminium/flameproof enclosure
8250/0 series empty enclosure,
8250/1 series terminal box,
8250/5 series control panel/control station
6.2.3 Installation Conditions
Distances, creepage distances and clearances
▶
When installing components, the creepage distances and clearances between the
individual components, as well as between the components and the enclosure walls,
must be sufficiently dimensioned. For this, take into consideration the values in the
relevant standards/manufacturer's specifications.
Distance between the connecting units for intrinsically safe and non-intrinsically safe electric
circuits
▶
Mount partitions used to separate connection terminals at least 1.5 mm from the enclosure
walls, or alternatively ensure a minimum distance of 50 mm between the uncoated
conducting parts of the connection terminals (when measured in any direction around the
partition)
▶
Make sure that metallic partitions
• are at least 0.45 mm thick
• are earthed
• are sufficiently strong and rigid
• have sufficient current carrying capacity.
▶
Make sure that non-metallic, insulating partitions
• are at least 0.9 mm thick
• have the requisite comparative tracking index (CTI). To find out what this should be,
refer to standard IEC/EN 60079-7 and the information on the voltage that occurs
(see the "Technical data" chapter).
• are reinforced to prevent deformation
Intrinsically safe circuits
▶
In intrinsically safe circuits, use only insulated cables and conductors with a test voltage
of at least 500 V AC and a minimum quality of H05.
▶
Calculate the insulation test voltage for the insulation and separation of terminals and
conductors from the sum of the rated operational voltages of intrinsically safe and
non-intrinsically safe circuits.
• In the case of "intrinsically safe to earth", there is a minimum rated insulation voltage
value of 500 V (otherwise, double the rated operational voltage of the intrinsically safe
electrical circuits).
• In the case of "intrinsically safe to non
-
intrinsically safe", there is a minimum rated
insulation voltage value of 1500 V (otherwise, double the rated operational voltage plus
1000 V).
Clearance and creepage distances of intrinsically safe components
▶
Make sure that the creepage distances and clearances between the uncoated,
conductive parts of connection terminals of separated, intrinsically safe circuits to earthed
or potential-free, conductive parts is equal or greater than the values of EN IEC 60079-11,
Table 5.
▶
For separated, intrinsically safe electric circuits, set up a safe distance between the
uncoated, conductive parts of external connections, which meets the following
requirements:
• Minimum 6 mm between the separated, intrinsically safe circuits
• At least 3 mm to earthed parts if a possible connection to earth has not been considered
in the safety analysis.