SWA and Plastic Boxes

[Burnt Fingers]

I'm using 1.5mm 3 core armoured cable. One of these cores is a lovely earth. However - I am terminating outside to a plastic box - new fangled pre threaded Wiska boxes, which are very nice but I have no way of securing my banjo and linking it at this end. This would leave my Steel Wires unearthed.

Am I being stupid or should I change boxes and do my normal stuff, lol.

The SWA does not run from the DB, rather from a plastic box that is fed from an undergroud supply in PVC armour, which is where I get my earth from.

I think I have my answer already but I'll post anyway whilst i find my insulin....thanks all

 

[mogga]

It's not always possible to gland into the bottom of a box and what if some one drills say and 8mm hole for a 6mm nut etc, the more hole you put in a box the more chance you have of water getting in. How can you be sure that after drilling the hole that you haven't compromised the integrity? It's the same reason the fixing holes for most IP rated boxes come with seals or are separated from the main internal part of the box like the mk outdoor switch range because the holes let water in. If you can avoid it by putting the banjo on the inside why not??

check IQs link earthing nuts are better invention than sliced bread as for water getting in Galv boxes also suffer loads of condensation issues

 

[gaulty]

I'm not talking about water defying the laws of gravity and getting in from the bottom lol if you have glanded in at the top water can get in through the banjo hole that's all
earthing nuts are great but my boss won't always get you what you ask for! I usually get his old battle cry of "DO YOU KNOW HOW MUCH THAT COSTS" even if it's pennies lol I swear if he ate a coal he'd s**t a diamond!

 

[Risteard]

Good idea to sandwich the banjo between two locknuts inside the enclosure due to the risk of the plastic creeping and earth continuity being lost or compromised. As said earlier though the Wiska boxes have a proprietary earth bar designed for them.

 

[pushrod]

i'm not denying that you can put the banjo inside and bend it to fit the lug, just that i can't see water getting in at the bottom. also, it's common practice to drill a small hole in the bottom to let any water OUT.

In my case that's the hole to let the ants get in and build a nest lol.

For the continuity of the steel nothing to stop you having all the banjos on the outside and keeping the lugged earth wire on the outside as well. Mind it doesn't look too smart if it is on view. (couldn't get the "where to buy earth nuts" link to show me anything but a map!)