# DIN Rail: You might Need This

#### Yaakov

Joined Jan 27, 2019
2,381
If you haven't been around industrial electronics systems you know not be familiar with DIN rail, but you might be happy to learn about it.

DIN rail is a global industrial standard for mounting electronics, including things like PLCs and MCUs, terminal blocks, power supplies, relays, and more. The "DIN" in DIN rail is for Deutsche Institut für Normung, the German standards institute that originated it.

In the past, DIN rail meant spending a lot of money. The industrial applications it was designed for needed very high reliability components and the cost of ensuring that reliability meant high prices.

Today, there is so much coming out of China that DIN rail components are downright affordable. There are also specialty items like DIN rail compatible breakouts for Raspberry Pi and Arduino IO with nice terminal blocks, as well as cases for both. Power supplies of all sorts can be had for tens rather than hundreds of dollars. Optoisolated relays, solid state relays, timers, comparators, and other interfacing components are available making the entire thing like automation lego, all mounted neatly on a metal rail.

The DIN rail itself comes in various sizes. The most common is the TS35 35mm size with a 7.5mm flange.

The modules clip onto this rail and can be positioned anywhere along it. the modularity makes service, revisions, and expansion easier.

You will find a lot of great DIN compatible components simply by searching Amazon, Ali Express, Ebay, or your favorite low price source. I encourage you to investigate this if you are building a new project that needs to have multiple components housed and interfaced. The end result is a neat looking, easy to work on system.

Last edited:

Joined Jul 18, 2013
22,641
AGREE:
Many components (almost all) come with DIN rail mounting capability Transformers, contactors, relays. terminals,fuse holders, to name but a few.
The version shown appears to be the most popular style now. You don't see the G style much now.

#### SamR

Joined Mar 19, 2019
3,180
Necessary piece of hardware for PLC cabinets.

#### Yaakov

Joined Jan 27, 2019
2,381
AGREE:
Many components (almost all) come with DIN rail mounting capability Transformers, contactors, relays. terminals,fuse holders, to name but a few.
The version shown appears to be the most popular style now. You don't see the G style much now.
I really don't think enough people know about/use the DIN ecosystem and it's really brilliant. Also, wire ferrules.

#### nsaspook

Joined Aug 27, 2009
8,163
Most of us instrumental build guys have been using DIN and ferrules for decades but it's been expensive.

Almost all of my prototype machine controllers used DIN.

Last edited:

Joined Jul 18, 2013
22,641
Most of use instrumental build guys have been using DIN and ferrules for decades but it's been expensive.
Almost all of my prototype machine controllers used DIN.
The expensive cost is also the tooling, which is usually not feasible for the DIY'er.
I built cabinets for a few decades and usually invested in hand tool equipment by Weidmuller, nice stuff, but a bit pricey!
Also the use of wire ducting (PanDuct) neatens up the cabinet a little..

#### cmartinez

Joined Jan 17, 2007
7,290

I too, have been using DIN rails for decades. And lately, I've been using mini-DIN to assemble distribution boxes in my machines. They make wiring (and life in general) the hell of a lot easier.

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,556
I never saw it before and I used it pre Internet. Probaby, the first time is used it was in 1984 to do power distribution Not sure I did it right. It was about six 1500 W power supplies and one 300 W one at 208V. Each power supply had a breaker, but the wire from the distribution to the supply wasn't protected or enclosed.

Later, the method was changed to mounting a load center (Breaker panel) on the side of the rack and it was plugged into the wall. This also allowed 120 and 208 V circuits.

We a bunch of similar evaporator systems and, I think, everyone too turns to make them better. From using the same twist lock on the pumps and a KF fitting so they could be swapped out easily. They were hard-wired when I was hired.

When I showed up we had this wacky Eurotherm controllers with no load fused or current limit, Variacs, temperature guages in random-looking panels. They got incrementally better within budget constraints. I wasn't allowed to fully enclose say a panel consisting of an analog voltmeter, analog ammeter, variac, fuse and switch. So, these panels were installed on "open racks". Not my idea. The other panel would be a couple of temperature controllers and thermometers.
Adding current limit and load fuses meant rarely replacing $25.00 semiconductor fuses. Finally, they were replaced with a Ramp Eurotherm controlling a C power supply. It helped bringing out all of the power supplies to 40A terminal blocks and then terminal blocks to the evaporator.. I think I used the "J" style rail which I quickly abandoned. I used the DIN construction to build instrumentation into 19" Rack cases which I thought was unusual. Most of my wiring was 18AWG reduced stranding so you get flexible, but not too flexible wiring. The wire stays where you put it. A lot of the problem was quantity. You need a piece of wire duct and you have to buy 50'. I use DIN rail for my home networking stuff. www.Winford.com is useful for DIN rail and mounting brackets. I make bases using wood and T-nuts and a Forster drill bit. The bit makes the T-nut flush or below the surface. One set holds the bracket and the other hold the product such as a router. Last edited: #### strantor Joined Oct 3, 2010 5,505 I too, have been using DIN rails for decades. And lately, I've been using mini-DIN to assemble distribution boxes in my machines. They make wiring (and life in general) the hell of a lot easier. You missed the opportunity to call out the cage clamp DIN rail terminals in your pictures. Those are also great! Much better than traditional screw terminals IMO. They do not loosen over time from vibration. Also you can clearly see where the wire goes in. Inserting wire into the bottoms of screw terminals, it is sometimes hard to tell if you've got the right slot. Also you can't see if there are any whiskers poking out (assuming you aren't using ferrules). The only drawback is that you can't cram 15 wires into one terminal, which you shouldn't be doing anyway. OH, and it's sometimes hard to put a meter probe on them. I'll up the ante on the cage clamp terminals though, have you seen these pluggable cage clamp terminals? Also I'm a big fan of these: and these: Thread Starter #### Yaakov Joined Jan 27, 2019 2,381 Wago also make push in DIN terminal blocks, but they aren't cheap. #### MaxHeadRoom Joined Jul 18, 2013 22,641 I think I used the "J" style rail which I quickly abandoned. Most of my wiring was 18AWG reduced stranding so you get flexible, but not too flexible wiring. The wire stays where you put it. A lot of the problem was quantity. You need a piece of wire duct and you have to buy 50'. Maybe that was the Gstyle? I used TR64 control wire alot due to its smaller OA dia per each wire gauge used, not so heavy insulation, but sufficient voltage rating, this way it small wireduct can be used, I used to buy duct in 6ft length? #### cmartinez Joined Jan 17, 2007 7,290 Yes, I have... and I'm quite familiar with all of Wago's line of product$ ... they ain't cheap. But I make extensive use of their PCB terminal blocks in most of my circuits.

I recently found the Chinese knock off at less than half the price... with the exact same quality.

#### strantor

Joined Oct 3, 2010
5,505
Wago's line of product\$ ... they ain't cheap.
I recently found the Chinese knock off at less than half the price... with the exact same quality.
probably because they both come off the same production line in China. First & second shift run with the Wago stencil printer turned on. Third shift for some reason always forgets to turn that printer on, and what do you do with 5,000lbs of unstenciled levernuts? would be a shame to throw them in the trash.... every single day 365 days a year.

#### cmartinez

Joined Jan 17, 2007
7,290
probably because they both come off the same production line in China. First & second shift run with the Wago stencil printer turned on. Third shift for some reason always forgets to turn that printer on, and what do you do with 5,000lbs of unstenciled levernuts? would be a shame to throw them in the trash.... every single day 365 days a year.
Those knockoffs have subtle differences in them that make it easy to tell they were not manufactured using neither the same mold nor the same terminal forming machinery ... and to be fair and to clarify my previous comment, their quality is almost imperceptibly lower.

Joined Jan 15, 2015
5,876
Din rail was my best friend.

All my relays and IO modules. Been retired about 8 years now and the above was a few years before I retired. I even have stuff on din rail here at home.

Ron

#### KeepItSimpleStupid

Joined Mar 4, 2014
4,556
I even have stuff on din rail here at home.
it's like getting hooked on an Erector Set (Back in the day).

#### xox

Joined Sep 8, 2017
528
It is unfortunate that we as a society have become so dependent on Chinese products. It's not just simple matter of economics either. There are hidden costs that come along with it.

We have no control over the quality nor safety of these products (think smeltered electronics). They skimp so much that nothing in general is very durable. And pouring money into their tech industry, how can that not be a detriment to national security?

We should really rethink our policies on this. Subsidize some of those industries if we have to. We need to take our manufacturing back.

#### cmartinez

Joined Jan 17, 2007
7,290
We need to take our manufacturing back.
And to do that, we need to rethink our understanding of the word "profits"