Technical Talk – The use of shrouds on cable glands
Friday, 20 May 2011
One of the occasionally controversial issues associated with HA electrical equipment is cable glands - in particular, the use of shrouds on the glands. Shrouds are commonly specified and used on glands outdoors as an aid to weather proofing. However, they may in fact have the opposite effect, by acting as moisture or water traps.
There is no legal requirement to use shrouds. Cable glands are certified without shrouds fitted, so a shroud is not required to achieve the IP rating – the gland does this by itself (provided it is correctly installed). The standards actually state we must protect the glands against corrosion (AS/NZS 60079.14 Clause 5.9; 9.3.9) or (AS/NZS 2381.1 Clause 1.8.14.1) so it could be argued that the fitting of a shroud promotes corrosion via their tendency to trap water and therefore they should not be used. If it is a requirement to fit a shroud (site policy) then it would be far safer and a better idea to use a Denso-type, grease-impregnated tape, which excludes moisture and if wrapped properly will not act as a moisture trap. Denso tape is still easy to remove (albeit a bit messy) for inspections or repair purposes.
