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Wire Number Direction - Is there a standard?

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live1wire

Electrical
Mar 1, 2019
3
thread248-226716
An answer to this.
i think there is only one correct way and a very good reason why.
MOD standards were always to read from termination end.
very simple and very obvious reason why!
to avoid any confusion in reading it.
if colour coded numbers are used you can read the colours. you always read from end of wire. so 123 would be brown, red, orange if you read it wrong it would then become 321.
or with black on white numbers you would know 99 is not 66.
 
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Most of the panels that I see have vertical terminal strips. The direction of the numbers is always so that the numbers are right side up.
That way you don't confuse 99 with 66.


Bill
--------------------
"Why not the best?"
Jimmy Carter
 
what then if cables are disconnected? which is why a correct all the same method is required. we read left to right so this applies also from cable/ wire end. there is no valid reason argument to any other way unless you wish to just add confusion.
 
Different strokes.
Internal wiring and jumpers terminate on the left side.
Field wiring terminates on the right side.
Alpha-numeric numbers avoid almost all of the confusion.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
live1wire,

You would be driven insane by the high voltage products group of a Swiss company whose name is an abbreviation of Another Big Bill. They wired their substation bay controllers in un-numbered black single-core panel wiring. One of our techs removed a couple of multi-pole pilot relays before he realised that nothing was numbered: much embarrassment and a time-consuming point-to-point wiring check to put it back together.
 
I spent many profitable weeks on a similar line-up.
#1 sections of 13kV switch-gear with each door filled with relays.
We disconnected, point to pointed, numbered and reconnected every wire.
Our wires were an identical grey colour.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Scotty 'Continental' practice is not to number cables because it costs the manufacturer too much...

In my early days with control panels from European continent, I had an entire suite of panels rejected at a UK waste water plant.

Cost a fortune to number all the drawings and then the cables & wires.

After that we insisted on UK practice.

Continental panels became so expensive we stopped using them.
 
Another other idea - which I think is from the Continent, although I could be wrong - is to number each end according to where it should terminate, so two ends of the same conductor have different idents. Personally I hate this method, although some people think it is brilliant: it may be good from the panelbuilder's perspective but it's awful from a maintenance perspective.
 
Agreed Scotty!
"The continent"? What continent?
There are seven.

Hoxton that's nuts! They can get wire that's pre-numbered. The panel place can use the same black wire for everything, they just grab the number needed as they fab the panels it doesn't cost anything since they had to buy the wire anyway. So lame.

It's pretty nice too since the wire has the number printed on it every 5 or so inches. Makes it easy to trace thru zip-tied bundles. All you need to do is see which one it disappears into and go to where that bundle breaks out.

9c_skmylc.jpg



Keith Cress
kcress -
 
I think that if you live in the UK there is only one continent that really matters.
I could be wrong. grin

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
For us it depends on the customer preference. Some customers want all of the point to point vertical wire markers going the same direction so they don't need to turn their head to read the top and bottom switch connections. Others want the "from" terminal number to be closest to the terminal, which causes the top terminals to read up and the bottom terminals to read down. In this example they are all reading top to bottom.
pic_hwlnsw.png
 
Those cable markers in JG2828's photo are a creation of Satan: they become brittle after a few years, the print fades and they crack and fall off. Maintenance nightmare! [curse]

The Critchley Z type are fantastic, the numbers are inherent in the colour code even if the print wears off.
Takes a bit more effort from the panelbuilder, but the customer is always right. Especially when I'm the customer! [evil]

11375_600_500_g2cyvs.jpg
 
O Yes thats the way to do it.
just read the colours from termination end does not matter where it is installed or just laying lose.
the printed black on white does rub off and not always easy to read with no light when you got your head stuck in a panel.
 
Yeah, but wires only labeled on ends suck to trouble shoot with no schematics, which is 80% of the time. In a big machine you have no idea where that wire is going to. It could be thru a feed-thru to some other acreage of the machine.

Keith Cress
kcress -
 
ScottyUK,
I have used some wire markers in the distant past that rub off (dot matrix printer) and eventually crack. The ones pictured are actually very durable. They are Panduit "military grade" heat shrinkable labels that use thermal transfer printing. I've been using them for the last 12 or so years with no issues. They are used on indoor relay panels, so I don't know how well they would fare outdoors exposed to sun and UV rays.
 
That's interesting - Panduit's stuff is normally pretty good. The ones I recall were early 90's vintage and were falling apart within 10 years even in a nice controlled indoor environment. Visually very similar, presumably very different in quality.
 
I have seen most of the above.
Not sure why Germans do not label wires, I have seen this too many times over the years. If I touch these type of panels I label the wires, at least I will know what I did in these panels.

I know where a wire interlocks with another panel (usually the wire color is yellow or orange, this could be different over the world, USA standard). I try to get the electricians to label the wire with both wire labels from each panel. Because a wire number generated in another panel can have a completely different format versus the panel that your trying to interlock with usually.

You can also label a panel by a prefix.
CP1 = Control Panel 1 = wire number prefix = 1-
MCPA = Motor control panel A = wire number prefix = A-

Complete wire number for CP1 = 1-xxxxxx
Complete wire number for MCPA = A-xxxxxx

I thought 6 or 8 long wire numbers are readable, but now you would have 10 alpha-numeric label.

That way if your in a plant and looking at a panel or out in field you open a box you know where that label is generated from what panel.

But this way would have to be driven by the plant engineer or the controls lead for the project.
 
Junction boxes in field
I know of only one end user that had us provide labels on phenolic etched tags with a screw to attach them and had to put this on the junction boxes. That way eons of years later if the tags on wires did fade and all that rot. But this was a customer spec and not an OEM spec.

Customer spec paid for it. OEM spec is based on competitive price.
 
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