Cable glands are mechanical cable entry devices and can be constructed from metallic or non-metallic materials. They are used throughout a number of industries in conjunction with cable and wiring used in electrical instrumentation and automation systems.

Cable glands are mechanical fittings that form part of the electrical installation material. The purpose of a cable gland is to seal the cable and retain it in the electrical equipment that it is attached to. It should maintain the ingress protection rating of the enclosures, keeping out dust and moisture but it should also prevent the cable from being pulled out of the equipment and from being twisted whilst connected to equipment. If it is intended for use with armoured cable, the cable gland also provides an earth continuity function.

Cable glands may be used on all types of electrical power, control, instrumentation, data and telecommunications cables. They are used as a sealing and termination device to ensure that the characteristics of the enclosure which the cable enters can be maintained adequately.

Cable Gland Standard

For industrial electrical installations the need for compliance with standards is vital in order to ensure such things as occupational health and safety in the workplace, security and safety of earthing systems, functional safety, longevity of performance and continuity of supply for plant and equipment. The same criteria which are applied to the plethora of electrical equipment should also be considered as applicable to cable glands, in order for systems to be installed and operated reliably.

During the formative years of the rapidly expanding power generation industry in all over world, the acute need for a common standard reference document that could address cable gland requirements was recognised, and from this GDCD 190 was created. Latterly in the 1970's BS 4121 was superseded by BS 6121 with the introduction of the metric system of measurement across Europe. Majority of cable gland designs around the BS 6121 standard. However in particular the area where some manufacturer don't comply with BS 6121 are the maximum bore dimensions (Table-I) through the cable gland, the wall thicknesses as a result of the bore size discrepancies, and the sealing ranges that differ considerably from the standard.

European standard for Cable Glands EN 50262 was published in September 1998. The new standard is very different from the previous British standards BS 6121 in some important respects. A new IEC standard for “Cable Glands for Electrical Installations”, IEC 62444, was published in 2010 and in time this will be adopted in several countries across the world, including Australia. This new standard could have a profound impact on users and manufacturers, especially those who discover for the first time that the products they have previously used have not been tested to any current standards. IEC 62444 is similar to EN 50262 in that it is also a performance based standard, allowing manufacturers to produce cable glands of varying degrees of robustness some of which may be more suited to light industrial applications such as factory automation, whilst others may be more applicable to medium and heavy duty industrial electrical installations, such as power generation and distribution.