I’m starting work on a new project, and planning for all the wiring connections is already getting out of hand.
I’ve been using Wago Lever Nuts, which I’ve been using for a few years now, but even they’re not enough to tame everything.
Advertisement
I came across DIN-mounted terminal blocks, such as the screw-mount terminal from Phoenix Contact that’s shown above, and they seem to be almost perfect.
These types of terminal blocks are often used in industrial systems to help make wiring easy to manage, and so it makes sense that it’s the next choice for my gazillion-wire project.
It’s taken me some time to learn about all the nuances – what size blocks to get, what style, how the jumpers work, and what the different accessories do, but it all makes sense now.
The one confusion I have so far is about to utilize disconnect or test disconnect blocks to set up easy to toggle test and measurement contacts, such as for voltage and current measurements. I’m sure there’s an easy way to do it, but from how it looks now, my options are to use extra smaller blocks, or to use much larger blocks which have multiple connections.
The one annoyance is that you have to use them with DIN rails – special industry-standard steel channels, although there are some direct-mount options with limited features and capabilities.
There are multiple ways to wire up a project, and I’m happy to have found one more way to do things.
Advertisement
A number of brands offer these types of accessories, such as Phoenix Contact and Wago.
If you’ve worked with DIN-mounted terminal blocks before, do you have any tips you’d like to share?
Tony
Check out
Terminal blocks by Entrelec a company of ABB make terminal blocks for testing, metering and disconnecting circuits.
Other lines are Allen Bradley, Weidmuller,
peelman
I like using Aluminum DIN rail instead of steel.
McMaster-Carr has a pretty great selection of the blocks themselves. Amazon has some of the basic models, but depending on your needs you may get beyond what they carry. Many of the ones sold have the option to “gang” terminals together using a cut-to-fit center rail. So you can have two+ neighboring blocks acting as a single terminal. Two blocks would give you one input and three outs, Three blocks gives you one input and 5 outs, etc. You can quickly gang a bunch together for power distribution, or gang a couple for signaling and testing.
I highly recommend their use, but in my experience, and in the absence of actual rules or guidelines, the actual particulars are very much up to the design, space constraints, and preferences of the person doing the work.
Terminal blocks are just one facet though; when you start looking at DIN-rail stuff, you can quickly find yourself using them to mount your power supplies, you can build the entire system without having to screw anything but the rail to your enclosure.
Stuart
Do you have a recommendation for Aluminum DIN rail?
I figured I’d order a few sections of 1m steel rail, since that would save on shipping and I’d cut it down anyways, but don’t mind easier-to-cut aluminum.
Why do you prefer aluminum over steel?
Steve
We used a chop saw (fast and easy) to cut all the rails then run each end on a wire wheel to de-burr. Done,
fred
Do you use one of those lever-type DIN rail cutters?
https://www.amazon.com/ASI305001-Lever-Action-Cutter-Cutting/dp/B00MO817LC/
peelman
nope. Not even if they were made out of gold would I spend that much on something we would use so infrequently.
Typically I just use a sawzall and a then file to clean up the edges.
If I were building PLCs for a living and doing DIN rail every day though, you’d bet I’d be buying one of those cutters.
Steve Zissou
What are the application of using something like this in a residential project? I have never seen it before, thanks for education in advance.
Stuart
There don’t seem to be any residential applications, at least not in the USA.
I’ve seen some DIY home automation and home brewing projects that involve DIN terminal blocks.
My project is simple, but involves a lot of different switches, controllers, lighting, and motion elements, and it’s requiring more flexibility and adjustment than ready-to-use terminal blocks offer. The all-in-one-place mounting capability will also help a lot with cable management.
I have another project that involves a rat’s nest of test cables, which these blocks should also help with.
Steve Zissou
Would love to see a post on your project! Learning opportunity.
Jonathan Kutz
We use these all the time when building control cabinets for the skids we design and build.
I get most of if not all of what we need from Automation Direct, and any orders over $49 get 2nd day shipping free.
If buying in bulk, there are better sources, like direct from the manufacture, but since each my projects are usually unique, I don’t buy in bulk much.
Like a earlier commenter said, you can mount everything to the DIN rail, and you normally do, for quick change out of a part goes bad. The cost of downtime are some of the largest costs in my industry.
Farid
We use Weidmuller and Phoenix Contact mainly. You already mentioned Wago. Altech is another. Altech makes a miniature panel mount version that comes in handy.
The larger companies have different series of terminal blocks with varying level of available accessories and options (disconnects, fused blocks, test terminals, jumpers, multi level blocks, and component carrier blocks). So, it pays to look at a series before starting. It may be daunting for a first time user though.
A popular trend is to use the screw less block with spring action wire clamp or insulation displacement. Those are great for relatively low current control wires as they speed up installation.
The quality of the blocks varies greatly and depends how critical the applications are. In our applications we have currents ranging form few milliamps up to 100A, so top quality blocks and safety ratings are a must.
A few of hints:
-Sometimes block models are listed by metric wire size, e.g. Weidmuller WD10 can accept wire up 10 sq. mm , WD4 up to 4 Sq. mm, …etc.
-If you are using blocks that require wire stripping, like the screw-clamp type, then invest in a automatic wire stripper, like Stripax (once you use one, there is no turning back!). You can set the exact strip length and it will do it every time-very rapidly. Having the correct stripped length is crucial for proper functioning of the blocks. There is nothing more frustrating than troubleshooting an intermittent circuit only to find out that the wire insulation is pinched under the clamp.
-You can use multiple wires into one block (check ratings). I recommend using a wire ferrule if doing so.
– Never solder tin stranded wire before using in blocks – the clamp will loosen over time. If you’re worried about frayed wires, use a ferrule. Ferrules also add a little bit of strain relief to the wire. Altech makes nice once.
– Some screw clamps have a screw-lock mechanism to prevent loosening under vibration (e.g. Weidmuller and Phoenix). You have to torque the screw down to certain point to look the screw in. consult literature.
– use separators between high voltage and low voltage sections.
-35mm din rail is standard, so you are not locked into one one manufacturer. Automation direct has good pricing on those. Low quantities can be had a t McMaster Carr.
Farid
Oops…I really should have double checked my spelling and grammar in a few spots!
Stuart
I ordered some Altech direct-mount blocks, and Phoenix blocks and accessories in 2.5 and 4mm sizing.
I’ll likely order some Wago too. I can’t help but try out different styles.
I ordered some ferrules and will have a crimping tool on the way. I work with a lot of stranded wire, and figured that will help me tame them. A couple of double-wire ferrules are on the way too.
I’ll look into the Stripax, thanks! I guess it’s now under Paladin branding (https://www.amazon.com/Paladin-1113-Stripax-Stripper-Cutter/dp/B0006BHCFO/).
Would you mind if I republished your tips? If I read them a few days ago, it would have save me a lot of time hunting through catalogs and datasheets, which still don’t really offer a lot of advice. With these types of products, most manufacturers assume that you won’t look into the products without lots of prior knowledge and experience.
Stuart
Looks like the Paladin version has a lot more plastic than the WEIDMULLER one. I’ll shop around for something similar. I do have a Gardner Bender one, but can’t find it at the moment.
fred
What crimping tool do you recommend for ferrules? We did not do a lot of electrical work – but did some HVAC automation/control work and used some Panduit tools – but My old inventory list says that they were quite pricey.
Wayne Ruffner
I’ve used some excellent ferrules from T&B and their ratcheting crimper made them as fool-proof as all the other Thomas & Betts stuff. (But my experience with the ferrules is pretty short.)
fred
Thanks Wayne
I know you get what you pay for – but the T&B crimper I spied on Amazon is probably out of my (retired old guy) needs and price range (sort of like the Panduit tools I recall we had)
https://www.amazon.com/Thomas-Betts-Ergonomic-Installing-Ferrules/dp/B015TL7YVC/
Farid
Fred,
Unfortunately, all the ferrule crimpers I have worked with cost a fortune. We mainly use the the Altech ratcheting crimpers, such as the E110.000 or E110.005. These are actually made by either Conta-clip or Klauke. They work really well and can handle a wide range of wire sizes.
http://www.altechcorp.com/PDFS/New_Blocks/TOOLS.pdf
Weidmuller makes a series of excellent but expensive crimpers :
http://catalog.weidmueller.com/procat/Group.jsp;jsessionid=855740856D2571015F69ADD145D8F5A8?groupId=(%22group4236262754688%22)&page=Group
Note< the Altech crimpers I mentioned above are trapezoidal crimpers, meaning the ferrule is shaped into a trapezoid once crimped , except for the smaller wire gauges (20 AWG and below) which end up flat. The trapezoid shape fits the wire cage on terminal blocks from Phoenix, Weidmuller and others.
You can get crimpers that will do square crimps to fit elevator type blocks (e.g. Phoenix wire plugs and headers). There are also hexagonal crimpers.
It's best to match the crimp style to the application, so it gets really expensive on tooling. Square is probably the most versatile?
For home use, it might be more economical to use blade style wire crimps (e,g, http://www.newark.com/blade-crimp-terminals) . You can use your standard wire lug crimp tools for those. You can also get quantities of the crimps through ebay.
Stuart
I’ve got Knipex crimpers on the way from Amazon DE, and the price wasn’t too bad. There are side-loading and front-loading ones, I went with the front-loading ones, not sure why.
I’ll be giving the blade crimp terminals a try as well. I need a few for something else, saw that they’re suitable for terminal blocks, added a few extra to my order. But they might be a little short for certain terminal blocks.
Some mentioned wanting an 8-10 mm striped length, others 10-12 mm, and when I looked up the Wago terminal block specs, it said they require 12 mm stripped length or 12 mm ferrules.
They don’t say how long the straight-blade terminal blades are, but it seems like they might be too short for some blocks, too long for others.
Unfortunately, the only way to know is to order some to try out, which is what I did.
I really wish there was more info out there about these things.
fred
Thanks once again guys.
Wow – I learned a few things from your comments. Not just squashed down into any old shape eh! But trapezoidal, square and hex crimps. And I see – just like some better plumbing crimpers – some of these have a full-cycle to insure a good result.
It also appears that some crimp the wire from the side, some on-end and some seem to allow the dies to rotate in the frame so you can do both.
I’m still not sure if or how I’ll apply any of this – no home automation or test equipment projects on the horizon etc.
Farid
Stuart,
The Te-Connectivity (AMP) blade crimps are typically 0.5″ long. The JST brand ones come in a variety of lengths. Refer to the data sheet here http://www.newark.com/jst-japan-solderless-terminals/1-25-af2-3a/terminal-blade-2-3mm-x-0-8mm-22/dp/45X5653
Oh, how I long for the old datasheets that had every detail you need in one place. More and more they are harder to come by.
Farid
Hi Stuart,
I’d be delighted if you publish the tips. Thanks!
Regarding the wire stripping tool, the older Stripax pro were exactly the same whether you got them from Paladin or Weidmuller. We now buy all paladin brand. Weidmuller now has the Stripax Ultimate XL, which is perfect for the stiff insulated Teflon wire we use. The stripping jaws are replaceable, by the way.
We have had no issues with the plastic on these strippers so far.
Xcelite makes a similar product as well as Knipex, although I have experience with neither one.
Here are the Knipex models:
(https://www.amazon.com/dp/B003B8WB5U/)
and
https://www.amazon.com/Knipex-1242195-Universal-Insulation-Stripper/dp/B000X4PSUA/
Finally, you may want to to checkout the test sockets and plugs that you can add to terminal blocks. Using patch cables, you can easily create different test setups and configurations. Check out page 20 in the provided link. This is not the only way, but pretty simple way.
http://www.clrwtr.com/PDF/Weidmuller/Weidmuller-Screw-Connection-Terminal-Accessories.pdf
(I am only using Weidmuller link above as an example, as I am more familiar with it, but it is not the only product out there).
Stuart
Thanks!
I ordered that first Knipex model earlier, it’s already on the way. That second one looks interesting, and I didn’t see it in my search. If the first one doesn’t work out well, I’ll bump up my budget and try that pricier one.
My confusion isn’t about test adapters, but finding an appropriate disconnect block that has test points in both sizes of the disconnect, to be bridged using a current meter. Otherwise multiple blocks are needed, increasing complexity, footprint, and cost.
Farid
I know what what you mean. I always seem to run into situations where the available parts almost fit my need. It has been a while since I looked, but perhaps there is something new. Perhaps one of the PLC engineers can pitch with some new info.
In the past, I had a setup using three blocks to to accomplish what (I think) you’re trying to do. I setup one standard block for neutral. A used a second block for the Line but I took out the pass through bar form the block (or you can just cut-it in the center). I used a disconnect block (mine was fused) and connected in parallel with the “Line” block. You can use comb style external jumpers or just a piece of wire (and double ferrule). My series instrument was connected across the disconnected block.
Closing the disconnect block shorted across series instrument, thereby bypassing it. Opening the disconnect placed the instrument in circuit. A voltmeter can be added across the line and neutrality blocks using standard test terminals. I used it live to compare the effect a series circuit on my DUT.
I know this adds one extra block, but it was a lot simpler and cheaper than using make-before-break switches.
Galen
Hi Stuart,
Phoenix Contact makes blocks that use both a disconnect and test socket screws. This means you can break your circuit and connect test probes all in the same block. Is this what you are searching for?
https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=3046171&library=usen&tab=1
To use this block you would start with your test probes in both screws (test socket screws are hollow, allowing a probe to be inserted and secured). Next, just break the circuit by rotating the orange lever up in the middle with your screwdriver. This would make the connection run through your meter, allowing easy measuring.
Stuart
Thanks, Galen!
I didn’t order any of those knife disconnect blocks, but I did order some of the new style. 2 in P/P configuration, and I also have 2 ME blocks in P/P configuration, with the hollowed test screws.
Ideally, what I’d love for are 2.5 or 4 mm^2 sized blocks similar to this 6 mm^2 block:
https://www.phoenixcontact.com/online/portal/us?uri=pxc-oc-itemdetail:pid=3035700&library=usen&tab=1
where there’s a disconnect and spaces on both sides for both jumpers and 4 mm test plug adapters.
But, I’ll make do with what’s available, it’ll just require a separate block or two at times.
Galen
Hi Stuart,
How did your project eventually turn out? Was it a success?
Phoenix Contact did launch a PT product with the dimensions you’re listing. It’s part number 3212139. I’d be happy to send you a few if you’re interested in testing them out!
seb
well, in France and Belgium (those are the two i m fmiliar with) everything in your home is actually mounted on DIN rail, those rails are mounted inside standardised Electrical panel boxes, as are the VDI (Voice, data, image) concentrators and repartitor (new constructions being required to have a centralised VDI infrastructure to distribute phone, voice and TV data). The breakers , earth fault breakers (dont know the english name for those , Interrupteur Differentiel in french), clocks, remote switch, everything. Most home automation system are available in DIN mount format(things like IPX 800 or KNX modules). http://www.installation-renovation-electrique.com/images/12-remplacement-tableau-electrique.JPG for an example.
Anyway, i d look at Schneider Electric http://www.schneider-electric.us/en/ or Legrand http://www.legrand.us/ gear, Wago obviously also. For multistranded wire as recommended above use a crimped connector and dont solder.
I wont give yo uany other advices as the electrical work is Very Very different in US that it is here and i m not too familiar with how things are done over there.
Phillip Kimmet
I use hundreds of terminal blocks every year on panels that I design and build. I have been buying terminal blocks from automationdirect.com they have great service and 2 day free shipping and prices that will beat anything from phoenix contact. Once i started doing the man on a typical panel I build I saved almost $500 a panel just in terminal blocks. I know its all about preferences but i always chose screw type terminal blocks over push in because i feel its a tighter fit, but for jumpers i always choose push in jumpers because i have seen to many times where the screw in jumpers don’t get tight. Just somethings I have found also if you are doing anymore electrical work like this i would really check the website out not trying to be a salesman but when my company wants me to build a good panel at a good price its the first place i go.
Peter Fox
My day job is wiring Panels for an independent panel shop, so I have seen and used a very large number of brands and styles of terminal products. The current panels I am working on have about 400 terminal on them. We probably use many tens of thousands per year.
If you want cheap and easy to source Automation direct is good. However the quality is just not the same as one of the larger manufacturers, you get what you pay for.
In our shop when we get the freedom to chose what terminals to use our choice is Wago for CageClamp (spring clamp) and Phoenix contact for screw type. Its really hard to go wrong with either. I also personally like phoenix’s spring clamp products. The other big name is Weidmuller who makes most of Allen Bradley’s current offerings you can’t really go wrong with any of the three from a quality stand point.
I will also strongly recommend spring clamp over screw type for most applications as they handle repeated connection and disconnection better (no screws to under or over tighten or break). They also do not loosen over time. They even make reconfiguring easier if you use the larger 3 and 4 hole blocks as you can have each wire in its own hole so when you want to move or add a wire you so not have disturb any other wires.
Lastly wire ferrules are highly recommended if you want to change and reconfigure easily. For low cost look at Automation direct or Ferrules Direct. There is some variation in quality from the top brands such as Panduit, Weidmuller, and Wago but not enough to matter. We use Panduit mainly from a UL listing stand point (we are a UL 508 certified shop) but we have used ferrules from the other sources and there is not much real difference. As far as tooling there are plenty of low cost Chinese made crimpers that are good enough for light use or you can get some more basic but high quality tools from Knipex like the 13-01-160, which will work equally well.
Steve
A great companion to Din rail is slotted Wire Duct.
Bruce
I use direct mount screw down wire terminals all the time. DIN can be nice but I find that once a project is complete and tested, I rarely have to touch it again. Why go to the extra expense of DIN mounting when you aren’t ever going to touch it again? I prefer to use fork connectors under a good screw terminal. I usually size the block for how many connection I’m going to need of a given type. IE, I group my inputs on a block and my outputs on a block. If it’s a big system I group by either type of field device or system. IE all the pumps or things that feed system 1 or system 2.
The screw terminals give me an easy place to take voltage readings and I can usually take the top off the wiring loom if I need to take a current reading.
All this advice is moot if your actual project is going to be a continual work in progress for testing new devices are just to fart around with new toys.
Farid
Our old products used screw terminal strips back in the 60 and 70s. However, as safety standards evolved, it became apparent that those connections did not fit as the screws were exposed. Many of our customers would not accept them. The blocks discussed here are finger safe. In applications where a worker may have to be around the circuit, this is a lot safer, and takes less space. In applications where the connections are sealed in a box and no one needs to bother with, I agree with you.
Bruce
Yeah, all boxes are at least cam locked at a minimum. Doesn’t matter what kind of terminals you use, boxes are closed unless testing.
Wayne Ruffner
All this reminds me that “DIN” is barely adequate as a way to identify stuff anymore. Though in this instance, it worked.
In way too many settings, “DIN” is used, surprisingly successfully, to identify something specific (usually “DIN connector”) but out of context it’s useless.
Steve
You don’t HAVE to use DIN rail to secure these, you can use velcro or any number of methods…but DIN rail is so nice because you can snap the units off and on and they are a much cleaner and more secure install. I’ve done several projects using these and I’m never going back. McMaster-Carr, Automation Direct, and FactoryMation are all good. I go cheap and buy a bunch in bulk, you’ll go through more than you think…jumpering can be a nice way to conserve terminals, change direction of wiring, etc. and I like to use other DIN compatible items like breakers, contactors, etc. as well for a headache free install.
Peter
Interesting that nobody has yet mentioned there are several sizes of DIN rail.
https://en.wikipedia.org/wiki/DIN_rail
MOST people mean 35mm x 7.5mm (EN 50022, BS 5584, DIN 46277-3) when they say “DIN rail” but not always.
Darren
Make sure you dont put them on the din rail back to back or youll have yourself a short,
They can slide about a little on the rail so I always use the end blocks that screw down tight,
And sometimes if you use a terminal ment for a larger wire with a smaller one the screw can go down too far with some brands it also causes the terminal to separate
JSBSON
Take a look at LEVER-NUTS® without Limits: WAGO 221 Series Mounting Carrier
http://www.wago.us/wago/press/press-releases/overview/detail-11770.jsp
Stuart
I posted about the Wago Lever Nuts several times:
https://14cyiuhvcgv.com/wago-221-lever-nut-wiring-connectors-are-now-available/%3C/a%3E%3C/p%3E
https://14cyiuhvcgv.com/wago-wiring-lever-connectors-221-series/%3C/a%3E%3C/p%3E
https://14cyiuhvcgv.com/wago-lever-nuts/%3C/a%3E%3C/p%3E
While I use them with their DIN-mountable holders, they’re really no substitute for DIN rail terminal blocks. I think that both are designed for very different types of applications.