Cable Glands permitted under NEC & CEC wiring rules

Under NEC and CEC technical standards, cable glands must be tested using samples of the proposed cable type(s) before they can be approved for use in the intended hazardous location.

The technical standards explain what type of features the cable glands must have for each hazardous location (Division 1 or Division 2) and whether the cable gland is required to be sealed*. In turn, the standards refer to the use of a sealing compound around the exposed conductors, rather than a sealing ring or other sealing device deployed around a cable jacket, bedding or sheath.

Under NEC & CEC wiring practices, explosionproof cable glands must therefore be capable of incorporating an integral barrier seal. Not all electrical enclosures are required to be explosionproof however (see table below) and in the case of some Division 2 enclosures there is no requirement for the cable gland – or more precisely the cable – to be sealed*.

There is a very clear set of rules over what type of cable glands can be used in each hazardous location and these rules can be summarised as follows:

Class I Division 1 Explosionproof Enclosures

Class I Division 2 Explosionproof Enclosures

Class I Div 2 Non Explosionproof Enclosures

*NB: According to NEC and CEC wiring rules the definition of a ‘seal’ is a barrier seal installed around the cable conductors, so in this context, whenever reference is made to ‘seal’ it specifically means a solid barrier that is explosionproof.