Terminal numbering conventions

[DairyBoy]

hi all. On all the panels that I've built to date I've used the conductor number as the (DIN rail) terminal number. A new customer wants to see "X" references for the terminal block groups. So far so good, but the system is an MCC with several separated panels. Where there's two functionally identical panels, I've numbered the groups the same, but the wire numbers are say, 101,2,3... for the first panel and 201,2,3... for the second one. But where there's a third panel, is there a "convention" or common practice that dictates that the third one should continue from where the others left off, or could I just start again from X1 for each separate panel? Any thoughts? Cheers.

 

[Fred Mau]

If you've already started a convention of 1xx for the first panel, 2xx for the second panel, then continue with 3xx for the third and 4xx for the fourth etc.

The only 'rule' is consistency. Nothing is more confusing than a project that changes numbering conventions midway through.

 

[JesperMP]

You must adopt the "location" method.

Each panel or panel section gets a "location".
For example +A1, +A2, +C44.

Each group of terminals (aka "Terminal strip") get a number.
For example -X1, -X2.

Each terminal within each strip gets a number.
For example :1, :2, :3.

It is smart to give the cable exactly the same number as the strip, and the wires exactly the same numbe as the terminal.
And since cables wire numbers always go 1, 2, 3 ... etc, then the terminals should do the same.

So the functionally identical terminals in two separate panels have the numbering in one panel:
+A1-X1:1, :2, :3
and the other panel:
+A2-X1:1, :2, :3

The cables and their wires going out from these terminals would be:
+A1-W1:1, :2, :3
and
+A2-X1:1, :2, :3

It is simple.

On the outside of the panels it says "+A1" and "+A2" respectively.
Inside, the terminal strips each have a sticker "-X1", "-X2" etc.
Each terminal in the strips only have the short number "1", "2", "3" etc.
The cables have labels like "+A1-W1", "+A2-W1".
The wires have preprinted numbers on them already.

The end result is that cable "+A1-W1" and its wires connect to terminal strip "+A1-X1", and the numbers of the wires correspond exactly to the numbers of the terminals.

This is a nobrainer especially when you have panels, or machine sections that are exactly alike or very alike.
You can copy 100's of pages, and just change the location identifier, and you are done.

To also adopt the function identifier ("=") may be confusing for some, but the location identifier is easy to understand and can easily be implemented. Most modern Ecad systems support this already.

 

[TConnolly]

You may find this PDF about applying IEC 61346 in automation useful. It should help you understand the concept.

http://infoscience.epfl.ch/record/52611/files/IC_TECH_REPORT_200420.pdf

Personally, I think it a PITA, but if thats what the customer wants then thats what you need to do.

 

[JesperMP]

Alaric.
That document is not good for explaining what IEC 61346 is, or how to use it.
I strongly recommend THIS book, which costs a mere 40 euro.

What I wrote above only covers 10% of the standard, but is what 95% of potential users needs to know in order to use it. It is simple. If you are in doubt about details just ask me. We use it extensively.

(edited the link.)

 

[TheStarr]

I use a basic system but it has one more digit then the OP's system.

4 digits

First digit is panel number
Second digit identifies type (0 power, 1 input, 2 output, 3-9 extra)
Third and fourth are the wire number.

Examples:
1030 = Panel 1, power wire #30 (+24 vDC)
1031 = Panel 1, power wire #31 (0 vDC)
2146 would be panel 2, input#46

If a wire is split I add a letter to the end. Like if an output goes to a safety relay and then to the component it would be:
PLC > 2240A > relay > 2240B > component

Not a standard, but consistent and it works for me.

 

[JustAnotherSparky]

Each panel or panel section gets a "location".
For example +A1, +A2, +C44.

Each group of terminals (aka "Terminal strip") get a number.
For example -X1, -X2.

Each terminal within each strip gets a number.
For example :1, :2, :3.

It is smart to give the cable exactly the same number as the strip, and the wires exactly the same numbe as the terminal.
And since cables wire numbers always go 1, 2, 3 ... etc, then the terminals should do the same.

So the functionally identical terminals in two separate panels have the numbering in one panel:
+A1-X1:1, :2, :3
and the other panel:
+A2-X1:1, :2, :3

The cables and their wires going out from these terminals would be:
+A1-W1:1, :2, :3
and
+A2-X1:1, :2, :3

It is simple.

On the outside of the panels it says "+A1" and "+A2" respectively.
Inside, the terminal strips each have a sticker "-X1", "-X2" etc.
Each terminal in the strips only have the short number "1", "2", "3" etc.
The cables have labels like "+A1-W1", "+A2-W1".
The wires have preprinted numbers on them already.

The end result is that cable "+A1-W1" and its wires connect to terminal strip "+A1-X1", and the numbers of the wires correspond exactly to the numbers of the terminals.

This is a nobrainer especially when you have panels, or machine sections that are exactly alike or very alike.
You can copy 100's of pages, and just change the location identifier, and you are done.

To also adopt the function identifier ("=") may be confusing for some, but the location identifier is easy to understand and can easily be implemented. Most modern Ecad systems support this already.

This is an old thread but lets see...

What is the convention for multilevel terminal blocks? I'm currently using three level blocks due to space constraints. I'd prefer to implement a convention rather than going the adhoc route...

 

[willxfmr]

This is an old thread but lets see...

What is the convention for multilevel terminal blocks? I'm currently using three level blocks due to space constraints. I'd prefer to implement a convention rather than going the adhoc route...

What I have seen in cases like that is that each level gets its own name. So on each block you would have X1.x.x, X2.x.x, and X3.x.x. It works well, and is easy to understand once you get used to it.

 

[Tom Jenkins]

The only 'rule' is consistency. Nothing is more confusing than a project that changes numbering conventions midway through.

Absolutely. I have seen hundreds of numbering schemes over the years. The developer always thinks they are great and obvious, everyone else thinks they are horrible.

If you are consistent, and have a pattern, and show it on the prints, the users and service people will learn it and be able to do their jobs.

I do say you should try to avoid making the wire numbering so clever and info packed that it "eliminates the schematic". The more complex the system the less likely anyone but its developer will understand it.