DIY 16mm2 IP65 Junction box problem

[Solar2020]

DIY poster : Hello, I am trying to connect two 16mm2 wires together in an ip65 junction box, but the holes are not big enough for the both the wires to push into. I am looking for a junction box that can join two 16mm2 wires. I have tried googling , even ordered things I though would work, but did not...so i am now asking here. In context :

I have a home 1.2kw/24v Solar setup. The two wires I want to join , go from my 450ah Battery Bank to my 800w Victron Inverter, to the left in the photo below. I have included a photo of an ip65 junction box with two wires joining together to demonstrate what I mean.

Thank you in advance for your help

 

[Lucien Nunes]

FWIW I use a lot of the Italian-style commoning terminals as linked by the OP in post #5. Obviously they do not make as substantial a connection as a hex-crimped copper-tube ring terminal on a brass stud, but the screws fit well and can be tightened very securely and the terminal body is a substantial piece of N/P brass. Whether they are officially approved for fine-stranded conductors without ferruling is moot, the data sheet implies they are and I would use them as such in a pinch, but would be happier with a ferrule.

TBH, a bog-standard Henley block with the advantage of double-screws might fit the bill if the box is big enough. Actually, does it even need the box?

RS website is lacking when it comes to accessories like this

Spot on! You know they are there somewhere, but can you find them? Was better in the days of the paper catalogues with a human editor. The website search engine doesn't have much product knowledge!

 

[stevethesparks]

Try Line Taps - if they will fit in the enclosure

Sigma 25.0mm² - 35mm² Line Tap | Hellermann (NSYS25/35)

 

[Darkwood]

My link was just a quick search so as others have posted alternatives at cheaper cost it is down to you @Solar2020 which you go for, I tend to keep away from terminals with fine stranded cables unless they are ferruled up, the wires have a tendency to sometimes ride up the sides of the grub screw with poor contact and/or getting cut by the thread hence the regulations, this risk is eliminated with cage clamps methods as long as the manufacturer specifies they are suited to undressed connections.

 

[Lucien Nunes]

Yes, line taps too. As DW explains there is a risk in many types of terminal of the screw either not clamping all the strands of a fine-stranded conductor, or shearing them off, but the Legrand line taps in this size range (not sure about the Sigma ones) have a non-rotating clamping plate that is very gentle on the conductor and the strands cannot escape up the side, so I'd be happy with that I think.

 

[Darkwood]

@Lucien Nunes - been seasoned in this line of work means we can judge it for ourselves and know a good connection when we see one, I was however eliminating the chances of a poor termination where possible as the OP is DIY (and looking at his original picture too) and will not be able to make these judgements and as he didn't want the expense of a crimping tool I saw this as a good alternative to terminal screws.

PS never used line taps myself so I'll go with the flow on your advice on that.

 

[Solar2020]

Hi Lucien, Darkwood et al, thanks for the replies, it is all very helpful, I am learning a lot. I did not realise the sheer number of connectors that exist in the electrical world. I now understand the elevated risks of screws against clamps and the possibility of poor terminations. I have a lot to consider and watch out for.

I might buy a selection and judge each once they have arrived. I will purchase the additional end stops and clamps Darkwood, so thank you for providing the additional information

I might not be able to reply much more tonight as I am providing surf life saving sessions tonight here in not so sunny Cornwall, but will read any replies and reply back tomorrow

Thanks again for all the help

 

[Darkwood]

Well with all respect the sign out was most unexpected ( surf life saving sessions )

 

[Zerax]

If it were me... for 16mm2 stranded cables... I'd definitely be using decent hex-crimped copper-tube ring terminals then bolt to a stud as Lucien has suggested.

 

[Strima]

If it's just those two cables you're trying to connect and it's indoor then a Henley block would suffice: 5-Way SP 100A Service Connector Block 25mm² - https://www.screwfix.com/p/5-way-sp-100a-service-connector-block-25mm/82608#product_additional_details_container

 

[Solar2020]

Yes, I do a bit of surf life saving coaching in the evenings. Just a quick message to say thanks for all the help, the advice paid off and I have now joined the 16mm2 wires and everything works. In the end I used Sigma line Taps. Once I have saved a little more cash I will try and get a decent crimping tool. Thank you