UL 60079-0-2019 pdf free download

UL 60079-0-2019 pdf free download.Explosive Atmospheres-Part 0 Equipment – General Requirements.
— S I GO measured at (50 ± 5) % relative humidity;
—5 100 GO measured at (30 ± 5) % relative humidity.
b) by limitation of the surface area of non-metallic parts of enclosures as shown in Table 7.
The surface area is defined as follows:
• for sheet materials, the area shall be the exposed (chargeable) area;
• for curved objects, the area shall be the projection of the object gMng the
maximum area;
• for Individual non-metallic parts, the area shall be evaluated independently
If they are separated by conductive earthed frames.
The permitted values of the surface area can be increased by a factor of four if this surface area of non-metallic material is surrounded by and in contact with a conductive earthed surface.
The permitted values of the surface area can be increased by a factor of two if this surface area is, at the longest opposite sides, in contact with a conductive earthed surface.
Alternatively, for long parts with non-metallic surfaces, such as tubes, bars, or ropes, the surface area need not be considered, but the diameters or widths shall not exceed the values shown in Table 8. Cables for connection of external circuits are not considered to fall under this requirement. See 16.7.
c) by limitation of the thickness of a non-metallic layer bonded to conductive or dissipative surfaces, which is connected to earth with a connection resistance of less than I GO. For the purposes of this standard, dissipative surfaces are those complying with the requirements of 7.4.2 a). The thickness of the non-metallic layer shall not exceed the values shown in Table 9 or the breakdown voltage shall be 54 kV DC (measured across the thickness of the insulating material according to the method described in IEC 60243-1 with the additional requirements of IEC 60243-2 for DC testing);
NOTE 2 A painted enclosure complying with 7.42 C) and Table 9 only will not comply with 7.4.3 C).
d) by provision of a conductive or dissipative coating. Non-metallic surfaces may be covered with a bonded durable conductive or dissipative coating. The resistance between coating and either the point of bond (in the case of equipment for fixed Installations) or the farthest point of potential contact with the enclosure (In the case of portable equipment).UL 60079-0-2019 pdf free download.