Wire Number Direction - Is there a standard?

[DaveDLS]

Anyone know if there is a European standard that dictates the direction that a wire identification number should read? ie toward or away from the terminal its connecting to?

I've always applied the numbers so that they read AWAY from the terminal, now I'm hearing that a european standard dictates otherwise, but I can't find out which one it is.

Anyone have any experience or input on this would be grateful.

 

[slavag]

DaveDLS.
I don't know if it's some standard.
From my expirience with many types of cubicles:
direction is as you read books, from left to right or
from bootom to top.
Only my opinion.
Regards.
Slava

 

[Skogsgurra]

Hi Slava! You keep your books upside-down?

Gunnar Englund

http://www.gke.org

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

 

[slavag]

Hi Gunnar.
From time to time, yes....
Only in case if my DIN rail with terminals is horisontal and numbering of terminals from left in right direction.
BTW, intresting situation, what we can do in case of Arabic or Chienise or Japanise cubicles
Slava

 

[ScottyUK]

I expect them to be readable, so on a wire entering a terminal from the right the lug will be next to the first character of the ident, and on a wire entering a terminal from the left the lug will be next to the last character of the ident.


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If we learn from our mistakes I'm getting a great education!

 

[davidbeach]

Yeah, what Scotty said. Why on earth would someone put markers on upside down just so that the label would always read toward (or away from) the terminal.

 

[carnage1]

you label? I bet you even use more than one color wire when wiring power

Luck is a difficult thing to verify and therefore should be tested often. - Me

 

[waross]

I'm with Scotty and David on this. Don't put the numbers upside down.

Bill
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"Why not the best?"
Jimmy Carter

 

[slavag]

Hi Guys.

I think it's some misunderstanding between us, sorry, becouse my bad explaination .

label --->: 123-xxx(terminal)-123 (label)--->
vertical DIN rail. from left to right, or toward from left side--away from right side.

turn now this terminals on 90deg and DIN rail now is horisontal,
from bottom to top, or same toward to terminal--away from terminal:
3
2
1
xxx terminals
3
2
1

I hope that Im more clear now ;-).
Best Regards.
Slava

 

[jraef]

Years ao I worked for a German electrical equipment manufacturer in the US, but we were required to do everything "by the book", a set of "Planning Manuals" that were essentially their own internal re-hashing of DIN standards. In there, they laid out a very rigid plan of exactly how terminal blocks were to be oriented and how the wire numbers were to be applied based upon the orientation. You had only 2 choices for TB orientation: Vertical, with field terminations on the right as you fasced the cabinet, or horizontal with field terminations on the bottom. In the vertical orientation, wire numbers were to read left-to-right facing so as to read them standing in front of the panel, starting at the terminal. In the horizontal orientation, top to bottom starting at the terminal, facing so that you read them with your head tilted towards the right. So these standards basically followed what ScottyUK has said. I never saw the original DIN standards they referred to, but knowing Germans, they exist.


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[DaveDLS]

Thanks for all the comments so far, seems that if there is a standard its not well known, as nobody here or in my company has seen it. A lot of the replies mention 'left and right' but in my experience DIN rail nearly always runs horizontally so terminals are top and bottom, it then depends which way you tip your head to read the numbers. Personally I'm a 'left ear down' tipper (!) but jraef is a right ear down. Unless of course a standard tells you to read bottom to top.

Also, numbers might not just be applied inside panels, but on machine mounted parts too. When I worked in the tobacco industry, there was a lot of dust around (even inside cabinets when the doors were left open) also the numbered rings werent as good then, and the numbers eventually disappeared but the colours were visible, then there is no 'upside down' , you need a rule or rules to tell you which way to read.

 

[matthewm1965]

When I served my apprenticeship, I was taught to the then CEGB standards. All cable markers had to read away from the terminal, even if it meant it was upside down. Not sure if the CEGB based their standards on some BS. I've had countless arguments about this over the years with various panel manufacturers.
Matt

 

[ScottyUK]

What the CEGB says could be written on tablets of stone! Most of their standards were very good, but this one I will politely disagree with. Would be useful to understand their reasoning though: I don't suppose you have a copy of the standard? Often they included some good explanatory notes why things were done the way they were.



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If we learn from our mistakes I'm getting a great education!

 

[matthewm1965]

Sorry I don't have a copy of the standard. It was etched into my brain 20 years ago, when I was threatened with the sack every day if I didn't follow the standards

 

[ScottyUK]

Section 1.2 of the linked document supports what you recall from the CEGB.


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If we learn from our mistakes I'm getting a great education!

 

[controlsdude]

The biggest issue I see is the length of the wire number.

If you get past 8 letters for a wire number it gets unreadable.

using common sense I would never put a wire number upside down based on spec. think of the end user having to turn his head upside down based on this spec.

 

[ScottyUK]

Controlsdude - I agree with you regarding upside down idents.

Regarding long idents, any design engineer who uses more than 8 characters really needs to re-think his design unless it is a staggeringly huge panel. Numbers to identify cores are fine - lengthy text descriptions aren't necessary. Long idents can add to the build cost too if the panel spec forbids the use of printed labels, which many do because printed labels fade over time.


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If we learn from our mistakes I'm getting a great education!

 

[controlsdude]

Case in point: wire numbers turned 90 degrees due to the terminal blocks mounted horizontal on the bottom. I had a customer who complained a lot even though the field terminals were mounted on the bottom of the panel. This cuased the wire numbers to be shown pointed toward the ground readable left to right. I can not imagine a customer seeing terminal wire numbers upside down, I would never get out of a site or signed off the job if that was the case.

If I was checking out a panel at a panel shop and they turned the terminal wire numbers upside down, I would tell them to renumber them all. I would not accept a panel for that reason.