Wylex 100A dp isolators in plastic enclosures.

John Peckham:

Metal enclosures do not need to be replaced if the cable sheath is left on the tails all the way up to the main switch and the tails enter through a plastic gland with a rubber insert so 4 layers of insulation. Whiska and other manufacturers make glands for this situation.

These glands are marketed as "tail glands". They make no other claim except

 

Protection class

IP66, IP68 (5 bar 30 min)

Glow wire test

750 °C

Temperature range

-40 °C - 100 °C

Material

Gland Polyamide, Gasket EPDM

The function primarily is to hold the cables in place and offer good IP rating. Any other "benefit" that people may feel it offers is like a placebo. It is not implied by the manufacturers that it provides double insulation or reinforced insulation, quite rightly too. The "get out" for TT came with 531.3.5.3.2.201, but a bit late in the day. But at least that reg now gives the electrician, if they chose so, another path through the minefield of 421.1.201

Posted by whjohnson on Sep 28, 2019 6:19 pm

The 16mm tails are indeed sheathed all the way into the enclosure, and a standard CTS gland rather than a dedicated tails one

Is that one standard compression gland with both line and neutral in it or one for each tail?  If the latter, there will need to be a slot cut between the holes.

John Peckham:

Metal enclosures do not need to be replaced if the cable sheath is left on the tails all the way up to the main switch and the tails enter through a plastic gland with a rubber insert so 4 layers of insulation. Whiska and other manufacturers make glands for this situation.

These glands are marketed as "tail glands". They make no other claim except

 

Protection class

IP66, IP68 (5 bar 30 min)

Glow wire test

750 °C

Temperature range

-40 °C - 100 °C

Material

Gland Polyamide, Gasket EPDM

The function primarily is to hold the cables in place and offer good IP rating. Any other "benefit" that people may feel it offers is like a placebo. It is not implied by the manufacturers that it provides double insulation or reinforced insulation, quite rightly too. The "get out" for TT came with 531.3.5.3.2.201, but a bit late in the day. But at least that reg now gives the electrician, if they chose so, another path through the minefield of 421.1.201

Posted by whjohnson on Sep 28, 2019 6:19 pm

The 16mm tails are indeed sheathed all the way into the enclosure, and a standard CTS gland rather than a dedicated tails one

Is that one standard compression gland with both line and neutral in it or one for each tail?  If the latter, there will need to be a slot cut between the holes.