Published: 19 September 2011
Category: Technical articles
A cable must be properly fixed and supported throughout its length. In most cases, an armoured cable gland should not be used as means of support
This article is extracted from Snags and Solutions Part 3 published by the: NICEIC Group
Failure to adequately support an armoured cable can produce a considerable strain at the made-off end with consequences including:
The gland plate is subjected to undue stress and becomes distorted. The situation can become worse if two or more unsupported armoured cables are terminated on to a single plate.
The enclosure can become distorted or damaged
Some or all of the steel wires of the armouring may become disengaged from the gland, producing a degradation of the earthing arrangements and a reduction in mechanical strength. Under adverse conditions the armouring can be pulled out of the gland putting strain on the conductor terminations and leaving the armour unearthed.
Solution
A cable gland must not be subject to undue strain either due to the unsupported weight of the cable in the vicinity of the gland placing undue lateral strain on the gland (Regulations 522.8.4 and 522.8.5 refer).A gland is a means of properly making-off a cable and is, in most cases, not intended to be a means of support. It should be ensured that cable glands are not subjected to any significant strain. The cable must be properly supported throughout its length. cleats, saddle supports, ties, etc must be properly selected and installed. The recommended minimum bending radius of the cable must be observed.