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External Influences - Operating Temperature The Method of Explosion Protection
The metallic body of the gland is suitable for The cable gland must be certified to a suitable method
operating temperatures from –100°C to +600°C of protection (preferably the same) and for use in the
The seal material is generally the limiting factor. same gas group as the equipment into which it will be
Neoprene is suitable from –35°C to +90°C. fitted. Flameproof Exd glands are suitable for use with
Silicon is suitable for extended operating both Flameproof and Increased Safety enclosures as
temperatures of –60°C to +180°C and should be the have met the requirements of both the standard for
used for low temperature applications as the seal General Requirements within hazardous areas and the
performance can be maintained throughout the additional requirements of the Flameproof standard
lifetime of the installation. Increased Safety Exe glands are only suitable for
Increased Safety applications but not Flameproof
Earthing, Grounding, Continuity, Bonding or applications as they have met the standard for General
Insulation Requirements within hazardous area but not the
The gland may be required to provide electrical additional requirements of the Flameproof standards.
functions in conjunction with its basic functions
of sealing and retention. Earth tags can be used Gas Groups
to provide an electrical connection point to earth Gas Group I – Atmospheres containing firedamp found
the cable gland, and by extension the cable in underground mines.
armour or screen where it has been terminated Gas Group II – All other potentially explosive
within the gland. Alternatively it may be a atmospheres, group II is subdivided into 3 groups for Ex
requirement to insulate the equipment enclosure d & Ex ia:
from the cable armour. The most flexible and • IIA – Typical gas propane
straightforward way of achieving this is to fit an • IIB – Typical gas ethylene
Insulated Adaptor between the enclosure and the • IIC – Typical gas acetylene or hydrogen
gland.
ATEX categories
Ex Certification Within Europe we now have the additional
When selecting Ex certified glands for use in requirements of the ATEX Directive to consider, staying
Hazardous Locations it is important to ensure specifically with product selection this now adds the
that the product selected not only performs requirement to select a gland with a suitable category
the task required, i.e. terminating the cable, status for the equipment and installation.
but must also maintain the overall integrity
of the equipment into which it will be fitted. Mining (M): Category M1, M2
The following has been prepared to help gland Surface gases (G): Category 1G (Zone 0),
selection. However, when selecting equipment 2G (Zone 1), 3G (Zone 2)
for use in the hazardous areas the appropriate Dusts (D): Category 1D (Zone 20), 2
national or international standards or codes of D (Zone 21), 3D (Zone 22)
practice must be considered.
Temperature Classification
Hazardous Location Requirements To ensure that the surface temperature of the
Cable glands must maintain: equipment will not ignite gases or vapours in the
• The Method of Explosion Protection, Gas surrounding atmosphere, the equipment will specify a
Group & Temperature Classification ‘T’ rating based on the maximum surface temperature
• The Ingress Protection (min IP54, realistically that can occur during its operation. As glands are
IP 66 68) passive and do not generate heat they have no effect
• Impact Resistance (min 7Nm) on the equipment’s ‘T’ rating and this need not be
considered when selecting the gland.
