Plastic compression glands for T&E into metal CU

[Pat H]

I'm sure this will have come up but what are the thoughts on cable entry into metal CUs?
Obviously from the rear is simplest but if cables have to come in from below then do we need to use metal glands or are plastic ok?
I assume for RFC its best for both legs of the circuit to enter together (although I think in terms of eddy currents as long as the L & N in the T&E are together that's all that's needed)

Been talk of ensuring the fixings to the wall are fire proof but even if use plastic raw plugs the screws are metal and I can't see a box falling off if it got really hot.
Also thinking some Intumescent sealant around the back to help seal the rear entry cables will effectively glue it in place anyway!

(Hey spelt topic right this time

 

[Sparks999]

The requirement is for the enclosure to be flame retardant, no mention is made of the cable entries. If you use stuffing glands with T&E you should really replace the rubber inserts with those that have oval holes through them. T&Es on ring finals can pass through separate entries. Wouldn't be worrying about using plastic wall plugs.

Just did an EICR on a 3 phase DB that had feeds from the board all exit together through a bush and lockring, go to a rotary isolator mounted to the trunking next to the board and then the loads from the rotary’s passed through a different bush in the board and to a seperate bit of containment. The cables are 4mm or 6mm twin and earths supplying 4 32A SP commando sockets would this be an issue with eddys?

 

[littlespark]

Just did an EICR on a 3 phase DB that had feeds from the board all exit together through a bush and lockring, go to a rotary isolator mounted to the trunking next to the board and then the loads from the rotary’s passed through a different bush in the board and to a seperate bit of containment. The cables are 4mm or 6mm twin and earths supplying 4 32A SP commando sockets would this be an issue with eddys?

Not if the L and N of the same circuit run through the same bush…. Which they would, if all t&e.

 

[Sparks999]

Not if the L and N of the same circuit run through the same bush…. Which they would, if all t&e.

Thanks I did think that I just remember being told years ago at college you have to bring both of the legs of a ring through the same hole so wasn’t 100% sure

 

[davesparks]

Thanks I did think that I just remember being told years ago at college you have to bring both of the legs of a ring through the same hole so wasn’t 100% sure

You don't need to bring both legs of a ring through the same hole, that's nonsense.