Best way to connect many single core copper wires together - Page 1
Forum section: electronics / projects

author: JeanF
author_rank: Regular Contributor
timestamp: September 02, 2019, 10:56:04 am
content: Hi,what would you suggest to join together about 45 solid core copper wires ?wish list:a. Must accept many 1.5 and 2.5mm² wires, a few 4mm² and 6mm², as well as at least one 16mm² or biggerb. ideally spring clamp, not screw clamp (I may reconsider it as long as c. is fulfilled)c. one wire per holed. wire disconnection must be possible (either with levers as Wago does, or with “push-screwdriver-into-the-hole” slots)I know there are many DIN-rail mount terminal blocks available in many shapes, but most of them are designed so that each terminal is insulated from its neighbours. Maybe there are ones that have a spare contact at the back and copper “combs” can be used to join them all in a row, but I’ve not been able to find actual product references that could work; maybe I don’t have the correct search terms.I have seen variations ofthis, but I’ve had issues in the past with old copper softening and connections becoming loose when there are multiple wires in the same hole. Besides, these screw terminals apply torque on the wires and can shear them; the “rising cage” design is much better IMHO.I have also seenthis[ Attachment Invalid Or Does Not Exist ] , but the number of contacts is too small and wire size is fixed.Do you have any suggestions ?Thank you !More info on the context :This is an old house, the mains wiring was installed in the ‘70s. All appliances are 230v single phase, they were randomly split on three phases from the utility company; all the neutrals are tied together. The live conductors (only) are protected by fuses.They used a short (4 or 5 rows) piece of one ofthese(bigger than in the picture though, more like 25mm2), all the wires were bundled in groups of about 10 in each hole (on one side only). Ugly pieces of U-shaped thicker wire were used to connect the rows together from the other side. There were many loose wires....Recently a temporary fix was made using many 5-way Wago terminals. Indeed it works but it’s not pretty.I know some will say “meh, just have everything rebuilt with modern components and one 2-pole breaker per circuit, GFCIs on each row, etc etc and voila, no more neutrals connected together”; while this may be a sensible advice for the long-term, I’m still looking for easier, cheaper and quicker solutions for now ! Thank you

author: Rerouter
author_rank: Super Contributor
timestamp: September 02, 2019, 10:59:10 am
content: your after something called a "Neutral link bar" its a brass terminal block intended for many solid core connections with smaller wires, and 1 bigger one back to a line fuse. If your afraid of shearing the wires, use ferrule crimps on the wire ends, this way the crimp takes the shearing, not the wire.

author: richard.cs
author_rank: Super Contributor
timestamp: September 02, 2019, 12:12:43 pm
content: There are definitely DIN rail mounted terminals that can be ganged with little staple-shaped bridging links but I don't know the search terms for them either. "DIN terminal jumper" seems to find some stuff.

author: themadhippy
author_rank: Super Contributor
timestamp: September 02, 2019, 02:56:59 pm
content: Quotejumper bars ,for examplehttps://eshop.wieland-electric.com/categorie/en/din-rail-terminal-blocks/1000008637#navigation:attrib%5Bcat_url%5D%5B0%5D=%2Fcategorie%2Fen%2Fdin-rail-terminal-blocks%2F1000008637&attrib%5BCategory%5D%5B0%5D=Cross-connector&first=0However the neutral type bar mentioned above would be my preferred option.

author: Yansi
author_rank: Super Contributor
timestamp: September 02, 2019, 03:22:15 pm
content: Depending on what you do, there are tens of options.I do not think there is anything wrong with those generic neutral bars. They indeed may shear wires off, but in such case, you either over-torqued it, or used a shit one with incorrect screw design (edge with a burr). Consult the manufacturers manual for what the proper torque should be. You shall only use brand name stuff and follow what the manufacturer recommends. Mains stuff ain't no place for hacking and fun.I have never heard of any problems with using this type of connection bars you have linked. They are the go-to type for any typical household installation.But please, do not twist wires together, leave that stuff to our friends behind an ocean.

author: JeanF
author_rank: Regular Contributor
timestamp: September 03, 2019, 10:03:23 am
content: Thank you for your replies.Rerouter, the “neutral link bar” you showed looks solid. I couldn’t find any source for them outside australia though, let alone a not too expensive one; I’ll continue searching.About DIN-rail terminal blocks, I looked a bit harder yesterday (wago, legrand/viking…) and indeed it looks like most of them have two holes at the top, to insert jumpers. I didn’t find jumper bars longer than 10 rows, but it’s possible to insert two in a staggered way so I guess it would be possible to do an equipotential connection of any length.If I understood correctly these jumpers only allow to bridge identical blocks together. So wires of about the same size could be all bridged in batches, but I’m not sure it’s possible to jump between smaller and bigger terminals… So there seems to be no easy way to connect all these smaller “buses” to a bigger, 16mm² terminal, going to the main circuit breaker. I don’t think a single 2.5mm² wire can be used for that, as it would be grossly abused at full load (63A max). Besides, “official” jumpers are not rated for that either… And using 16mm² terminals for everything, even the smaller wires, sound wasteful (and expensive) to me...All this suggests that I should stick with screw terminal bars, as you guys say. If I’m not mistaken, french standards allow only 2 wires (of equal size) per hole, as a maximum, so I still need quite a big “neutral bar” to fit everything…Locally I can findthese, they are available from 4 to 22 holes. They can be rail mounted (1 to 4 identical terminal barsusing plastic bracketsThat could do the job… I wish these bars existed with smaller holes ; a pair of 1.5mm² wires in these 16mm² holes will look a bit funny. And as I mentioned before I’m not a fan of screws; they get loose… Spring terminals are more reliable in that way.Speaking of spring terminals, I also foundthis, what do you think ? They look a bit flimsy and plasticky to me, but they are officially approved. I would need two of them, and twomounting bracketsas well…Too bad I have to stick to approved components; it is quite tempting to roll my own solution and stick a bunch oftheseon a pcb with 2-oz copper…

author: Rerouter
author_rank: Super Contributor
timestamp: September 03, 2019, 10:28:20 am
content: I assume you may have more luck looking for whatever the french equivalent of "Brass Earth Block" or similar terms,They are quite cheap here, so I would imagine they should be the same over there, however I'm not familiar with your electrical code.https://www.tro-pacific.com/products/de-range-neutral-bar-12-way(Roughly 3 Euro + postage)I will also note brass screws in a brass block don't normally come loose unless you destroy the threads, brass is "sticky" and you generally need to re-crack the screws after they have been left on there own for more than 2 weeks,

author: Jeroen3
author_rank: Super Contributor
timestamp: September 03, 2019, 10:54:47 am
content: Unsafe bare brass blocks might be the simplest, for neutral many switchboards already offer one of these next to earth. If you don't have 1p+n breakers... (you should definetely get them)Otherwise the magic words aredistributionterminal blocks. Eg: Phoenix PTFIXWago, Phoenix and such have dozens of these types of things. They are different from modular terminal strip with a jumper in between.You might have to combine PTFIX with one of their UKH large-to-smaller wire cross section units to get one big cable to multiple smaller blocks.Keep an eye on the maximum current ratings and diversity factor.

author: Yansi
author_rank: Super Contributor
timestamp: September 03, 2019, 11:19:18 am
content: Quote from: JeanF on September 03, 2019, 10:03:23 amPlease be very aware of the current carrying limits of the jumper links.Good enough for supplying a number of sensors in an industrial application with small currents, but I'd not use this for POWER distribution.A good brass bus bar is still a bus bar, where no links can be broken, causing havoc in between appliances when the neutral (or earth) is floating somewhere partially.I'd suggest using a good old bus bar, with screws. There is nothing wrong or unsafe about them.