earthing the SWA cable armour in a rotary switch?

[HappyHippyDad]

Morning... sort of for me.

Have just got my rotary switch for the Hot tub and notice there is no room for a banjo inside as the front cover fixing holes are in the way. Just wondered what you guys do with this type of rotary switch? Perhaps a piranha earthing nut?

Have just contacted the local wholesaler who I have started using and he said the chaps dont usually earth the armour in a rotary switch which was a bit of a suprise!!

 

[Guest77]

I tend to fit the Banjo on the outside under the bottom where the armoured enters the box, and bend it down enough so I can get a bolt into it, the earth then connects to the banjo with a tiny hole into the side of the enclosure to enable the earth to get back into the enclosure from the banjo, it is a bit heath robinson but it works, the rotary isolators under 63 amp are terrible to work with if an armoured over 6mm2 is used.

 

[telectrix]

I tend to fit the Banjo on the outside under the bottom where the armoured enters the box, and bend it down enough so I can get a bolt into it, the earth then connects to the banjo with a tiny hole into the side of the enclosure to enable the earth to get back into the enclosure from the banjo, it is a bit heath robinson but it works, the rotary isolators under 63 amp are terrible to work with if an armoured over 6mm2 is used.

done same with wiska boxes where the gland entry is threaded and you can't get any sort of locknut on the inside.

 

[malcolmsanford]

I personally would fit a 4 x 4 adaptable galv box and then coupling and bush from the box into the isolator.

Then flyearth the banjo onto adaptable box and then take the flyearth into the earth in the isolator

 

[Marvo]

I personally would fit a 4 x 4 adaptable galv box and then coupling and bush from the box into the isolator.

Then flyearth the banjo onto adaptable box and then take the flyearth into the earth in the isolator

That would be the right way I'd do it but I'm guessing he's got such a small isolator because he's short of space. Either that or masochistic tendencies

 

[davesparks]

I personally would fit a 4 x 4 adaptable galv box and then coupling and bush from the box into the isolator.

Then flyearth the banjo onto adaptable box and then take the flyearth into the earth in the isolator

The problem with that is adaptable boxes these days tend to leak like sieves, so fitting then outdoors isn't great.

 

[SPARTYKUS]

The problem with that is adaptable boxes these days tend to leak like sieves, so fitting then outdoors isn't great.

Probably not much worry about that in Saudi Arabia :smilewinkgrin:

 

[Guest77]

The problem with that is adaptable boxes these days tend to leak like sieves, so fitting then outdoors isn't great.

It would also look like a dogs ear on the side of a air con unit as well.

 

[nickblake]

Love piranna nuts not used an banjo for ages

 

[Delboybully]

done same with wiska boxes where the gland entry is threaded and you can't get any sort of locknut on the inside.

When using armoured cable into a wiska box use the wiska earthing nuts- its dead easy and a joy to do

http://sparkydirect.s3.amazonaws.com/E/EC308_1.jpg

 

[telectrix]

wasn't that type of wiska box. the ones i has, the small b lack ones, there was no gland protruding inside the box,so no way of fitting anything inside.

 

[tigerpaul]

If the swa is on tray then put the banjo on the outside and then earth link to tray. Then use an internal core for cpc.
If you haven't got an internal core for cpc then you'd need a piranha nut or another banjo on the inside bent up so as to be able to connect a cable onto.
If the swa is cleated then forget about the banjo on the outside.
I wouldn't drill small holes in the enclosure for cables to sneak through though. That would ruin the IP rating.
Oh and we tend to use fibre washers at the gland entry as well now, it stops condensation forming inside apparently...

 

[shanky887614]

If the swa is on tray then put the banjo on the outside and then earth link to tray. Then use an internal core for cpc.
If you haven't got an internal core for cpc then you'd need a piranha nut or another banjo on the inside bent up so as to be able to connect a cable onto.
If the swa is cleated then forget about the banjo on the outside.
I wouldn't drill small holes in the enclosure for cables to sneak through though. That would ruin the IP rating.
Oh and we tend to use fibre washers at the gland entry as well now, it stops condensation forming inside apparently...

even if you used a stuffing gland?

 

[malcolmsanford]

The problem with that is adaptable boxes these days tend to leak like sieves, so fitting then outdoors isn't great.

So we don't use galv adaptable boxes outside anymore? Sort of makes you wonder why they are made of galv if they are not IP rated for outside use? Can't we get the box with that nice black rubber seal anymore? And I suppose being taught to drill a nice 1/4 hole in the bottom is no longer done? with your little dab a vaseline.

I guess if you use sub standard boxes they will leak, but I'm guessing that a decent box will still be rated at IP44. But I guess if you install in incorrectly it will leak.

Also though it is for a hot tub, are we sure that the box will be outside anyways?

 

[tigerpaul]

You could take the earth through a stuffing gland, but Sometimes I've seen it done where the earth conductor just passes through a little 6mm hole. That isn't really acceptable anymore.
As for adaptable boxes, they should be suitably IP rated, and the galv type ones generally are for indoor use only.

 

[HappyHippyDad]

I've fitted a piranha nut. It was very straight forward and I'm sure I shall use another one in the future. However a banjo costs pennies and the piranha nut costs £2 so i shall be sticking with banjo's for most jobs as they don't really take that much longer!

Thanks for the replies guys.