Tech document needed - Using DIN rail mounted devices properly

[Tmoose]

I'm groggy from Googling things like DIN rail mounting guidelines. And have not found much at all, even from manufacturers who offer components with DIN mounting features.

First it looks to me like the rails need to run horizontal, partly because most all the pictures show that, and second because I can picture a vertical rail full of typical spring clamped components sliding off the end, like a Shish Kabob. Third, there are some shock requirements for this system, and the DIN system looks to have a timid grip on the rail.

We are about to use the DIN system in an enclosure that only fits in an orientation that will result in vertical rails.

 

[Skogsgurra]

No, not vertical! Not if there is shock and vibration. You may use screwed-down end guides that keep your stuff in place. But I do not like the idea. Some of them DIN modules are easy to lift off, turning upwards, but tough the other way. Can you make sure that the shock only comes the "tough" way? Even so,I wouldn't do it.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[itsmoked]

Hi.

You can mount them any dang way yo want. Most parts won't easily slide off. BUT! Everyone who actually wants to worry about that can just use "END STOPS". They are just little clip on devices that are meant purrley to keep anything from moving down DIN rails. I use them all the time. They are even used as punctuation sometimes. To help make it clear something new is starting on the DIN rail, like between inputs and outputs or higher voltages and low voltages.

Example:

http://www.mcmaster.com/nav/enter.asp?pagenum=716

Note: The End Stops.

BTW: Mcmaster.com is a great place to pick up DIN rail terminal blocks without a bunch of hassle.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Skogsgurra]

Yes, terminal blocks are usually used that way. But heavy modules - and vibration? No.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[danw2]

Some DIN rail mounted modules have cooling vents in their housings where the vents are on opposite sides of one another. I've presumed that the modules should mount on horizontal DIN rail to orient the vents vertically to assist in convection cooling. But to tell the truth, I've never checked the installation manual for those I/O modules for a recommendation one way or another.

 

[jraef]

The DIN in DIN Rail is an old German standard, now adopted and supported by European Standard EN 50022 and world wide by International Standard IEC 60715. Both standards can be purchased on-line if you really want to delve into the design limitations and requirements.

But in general, the those specs include vibration limitations for devices with centers of mass at specific distances from the rail etc. It would then be up to the device mfgr. to apply that to their individual device. In the same vein, DIN rail standards don't delineate whether or not it is appropriate to mount a device vertically or not, that is up to the device in question. Most devices will have detailed mounting position and vibration specifications in their instruction manuals, another IEC / EN standard requirement. Manufacturers of devices with no such detailed instructions are probably using DIN rail mounting out of convenience but don't actually subscribe to or have been tested to those standards so should probably be avoided. In other words, if you have something that doesn't specifically says it is OK to mount on a vertically oriented DIN rail, you shouldn't do it. If it does, it will also tell you every detail about what you can and cannot do.

 

[Skogsgurra]

Yes, that makes a lot of sense. But.

Since there are devices with limitations, and you usually do not have all the specifications, and some (like the SITOP and other power supplies) can only tolerate a horisontal rail, it is a big no-no to put device holding DIN rails vertically.

You never know the mix, really. At least in shops where I have (had) any influence. Putting up rails both horisontally and vertically and then trying to figure out what device can be put where is just plain silly.

Vertical? For terminal blocks - yes. No probs. That's how they usually are used.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[itsmoked]

Yep.. You can mount DIN rail any way the things you're going to mount on it allow. Vertical mountings need end-stops that will hold for the conditions the system will be subjected to.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[jraef]

But even the end stops have limits Keith. A 40A power supply is not going to be held up by any commercially available end stop.

Incidentally, we just released a new power supply that now does away with DIN rail mounting - full circle in the design process eh? The reason was vibration. In transportation applications and other high vibration and shock load situations, the (horizontally mounted) DIN rail acts as a spring with heavy devices to amplify the vibration. So they went back to a metal back plate and 4 screws.

 

[itsmoked]

I ain't gonna by it that none of the end-stops work well enough to hold until the din rail fails altogether. I just did a search on "DIN end stops" there are ones with screw clamps, ones with stainless steel knives, ones with screws that engage the rail, all of them solid steel(no plastic). I have put on mere grounding spring blocks that I was unable to slide with all my strength down a rail...

I am surprised that the rail can add spring too, since most rail can be screwed down about every 2 inches. I can see some yokel screwing it down at just the ends, and then hanging pounds on the middle, bongybongybongy.

Granted, eliminating any way to din mount a product, will avoid the wrong end stops and poorly installed rail.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Tmoose]

http://www.rose-bopla.com/PDF_Files/Ch_01_Basic_Boxes/Aluminum_Dwgs/01Aluminum.pdf

part number - 013 1401885

not picking on these guys, but the M6 holes are on a shelf at each end, so DIN rails attached with those M6 holes will have a ~15 inch free span suspended at the ends

 

[ScottyUK]

If you are mounting something heavy use a chassis plate. There are enough mountings in that enclosure to accept one. If you're using terminals in a box like that then DIN rail is probably ok. The asymmetric rail - we know it as G-rail - is a lot stiffer than TS35 rail on long spans and is therefore a better choice. Choose the right material for the job. Any fool can design something badly - engineers should be able to do somewhat better than that, although this thread has got me wondering. Do we really need a standard to spell out common sense?


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Sometimes I wake up Grumpy.
Other times I just let her sleep!

 

[ozmosis]

It also depends what you're going to mount on the DIN rail. We supply some small VSD/VFD's that are capable of mounting on a DIN rail but we would not recommend the VFD is mounted so that the airflow, normally blowing bottom to top vertically, is then blowing horizontally.