M16 Grommets

[padawan]

Hey guys  

I need to terminate 6mm T&E, plus 6mm earth single, and 6mm SWA into an IP65 junction box.

The junction box i am using is this one

https://www.tlc-direct.co.uk/Products/LB9065.html

The SWA will be glanced into the 20mm knockouts, and the 6MM T&E and 6mm earth single will be rear entry, so far so good. I then noticed that the rear entry knockouts are both M16, which is a new one on me. I have had a look online but i can't find any M16 grommets (TLC don't stock them), the only thing i can find is m16 glands but obviously thats no good due to rear entry into the junction box.

Im not sure what i am missing, can someone please point me in the right direction.

Thanks 

P.S. Please excuse my ignorance.

 

[Andy™]

Im not sure what i am missing,

20mm drill bit?

 

[NozSpark]

Cut grommet smaller?

 

[Blue Duck]

Blow a hole in it!

Looks like the back of Andy™'s Van! :lol:

Wiska boxes all the way...

 

[Marvo]

I can't believe grommets are still legal in the UK, I think with the latest guidance about steel CU's that rubber grommets and that gawdawful edging strip stuff should also be outlawed. The cable entry isn't so critical when it's a plastic enclosure but cables entering a hole cut in steel is a different story. 

@padawan, you do get 16mm grommets but probably not so much at electrical suppliers, easier to drill the hole out to 20mm.

 

[roys]

Take it you don't like grommets then Marvo? Must admit I hate to see it when they are NOT used.

 

[Evans Electric]

You'll get 16mm grommets if you shop around .

But its a plastic box IP65 and I assume its outside so back entry will impair it's IP-ness . 

 

[Marvo]

Take it you don't like grommets then Marvo? Must admit I hate to see it when they are NOT used.

Yeah, I'd suspect a lot of the times they're not used, they probably were used but wandered/fell off.

I've always found it a bit weird, the UK regs are generally no nonsense belt and braces approach but there's the odd few practices that stand out like a sore thumb as being a bit lax. Grommets on cable entry and lack of proper male adapters on conduit entry are a couple of them.

 

[padawan]

Cut grommet smaller?

Im not sure why i didnt think of this tbh lol

Blow a hole in it!

Looks like the back of Andy™'s Van! :lol:

Wiska boxes all the way...

I did come across whisk box's while i was searching for grommets and they do look pretty good, but from what i could see they don't have any rear entry knockouts? or space to drill your own?

@padawan, you do get 16mm grommets but probably not so much at electrical suppliers, easier to drill the hole out to 20mm.

Again i don't why i didnt think of this lol

You'll get 16mm grommets if you shop around .

But its a plastic box IP65 and I assume its outside so back entry will impair it's IP-ness . 

Yeh i finally came across them on both RS and eBay, about 10 mins after posting my thread. I knew they must be out there somewhere.

Yeh its outside, but the manufacturers have put 2 knockouts in the back so i assume they reckon its IP-ness is maintained. My plan was grommet and silicon.

 

[Andy™]

erm... the knockout is there for you to fit your own IP gland. grommet and silicone is a bodge

 

[Jono Pashley]

Its plastic anyway so the grommet is a waste, Wiska Boxes have soft membrane entries in the back although i would still be tempted to apply a liberal amount of CT1 to keep any water out or fill the box with gel

https://www.tlc-direct.co.uk/Products/WK607B.html

 

[Marvo]

If you want to maintain it's IP'ness rather install a compression gland backwards if there's enough depth in the enclosure. (the gland on the inside and nut on the outside) .

 

[Andy™]

or use a wiska clixx

 

[Jono Pashley]

or use a wiska clixx

Aye they are good...especially when you can stock up once a year for free  :innocent

 

[Andy™]

of course. still got plenty left, hopefully enough til the next time

 

[kerching]

Aye they are good...especially when you can stock up once a year for free  :innocent

well,I like themAnd use a lot

 

[padawan]

erm... the knockout is there for you to fit your own IP gland. grommet and silicone is a bodge

Glands would be a nightmare to fix for rear entry, but if thats how it should be done then fair enough, thanks for the tip.

Its plastic anyway so the grommet is a waste, Wiska Boxes have soft membrane entries in the back although i would still be tempted to apply a liberal amount of CT1 to keep any water out or fill the box with gel

https://www.tlc-direct.co.uk/Products/WK607B.html

Ah i see, sounds like they are worth checking out, i might even even suggest them to my boss lol

If you want to maintain it's IP'ness rather install a compression gland backwards if there's enough depth in the enclosure. (the gland on the inside and nut on the outside) .

Thats sounds like a great tip, i will look into it for sure, thanks.

 

[Evans Electric]

Wiska boxes are good .  I've used the box you have there , they're OK but I don't like  the fixing holes in the back ....not very IP'ish really.

Fixing holes should be  the sealed tunnel type like the Wiska 's .

The IP rating is maintained by using the threaded holes in the sides really , shoving cables in the back is asking for it to fill with water .

 With those grey IP rated twin socket boxes I bring the cable out underneath , wrap with black tape , instead of drilling the backs & letting water in .

Not interested in what it looks like , its there to do a job.  

 

[Blue Duck]

just thinking.... would a 25mm galv stop end box be better? I tend to keep Wiska stuff surface to maintain IP'ness.?

Had a job the other day where I had to get the silicone out as the council contactor "extras" werent great and they took out a fair chunk of wall around the exit hole.