ISO 81346 and the real world

Reader David H asks:

In very large systems such as manufacturing plants, there are lots of different machines for lots of different reasons and they all have a complex list of subsystems, mounting locations, and connection points, this equipment is also often made by a variety of manufacturers, and much of the time we are buying something that we have no real control over the design.

Can this system (ISO 81346) be applied at the various levels of such massively complex systems?

For instance, the maker of a bottling system in one section of the plant has no knowledge of the larger overall system of the plant. That maker will label functions, locations, and products within his system. When it is installed in the plant, it now has a different, overall function and location that the original functions and locations will now live within.

Can that now be documented with all those levels of hierarchy?

Your answer is Yes and no….

First, the owner of the plant management needs to decide if they want to own and maintain a documentation system for the machinery in the plant, or not. I will be honest, I have seen many plants where management simply says that sounds like it will cost money and that’s the end of it. I assume because you are asking this question that you may have a need to create such a system and you want to know if this is one that you can use and have confidence in. I have total confidence that it can handle the most complex designs that you can think of BUT the problems that you will encounter using it are not often with the system, it will be with your current understanding of how to implement it and with others reactions to seeing it often simply because “they didn’t use it at the last place I worked” .

The scenario that you describe in your question is typical of the real world not a perfect world, in a perfect world all plants would be designed starting with a green field and there would be no unforeseen changes or additions of equipment over the lifetime of the plant, this of course is not reality.

If you are thinking about implementing such a system get comfortable with the fact that there will be some things you will have control over and many other things you will have very little control over, this is not good or bad just reality. By this I mean if you are creating such an identification system, you will have full control to identify all aspects of the machine to your liking only for the machines that you design.

For equipment that you purchase from another manufacturer you will very likely just design the interface circuitry around the machine and accept the internal circuitry for what it is. Typically for most equipment provided by others your Interaction will typically be limited to the main power feeds, an ethernet connection and a label with your identifier on the main cabinet, the rest of it will be treated like a black box where the internal details are provided by the manufacturers own documentation.

EPLAN’s Page Navigator combined with the page type external document can go a long way to simplifying your documentation management issues as make it very easy to add a PDF or Autocad sheet set to an EPLAN project so that everything you need is contained in the project database.

Identification methods for Industrial systems

Reader David H writes:

Are there pre-defined letter codes for the function aspect like there are for the product aspect?

Yes, the same designators that an electrical engineer or designer would use to identify devices in an electrical system (81346-2) can be used to identify the functional aspects of a design. As a control systems engineer I often use the identifiers found in ISO 81346-2 Table 2 to identify the part aspect (+)  of the devices in my projects. However the more generic “parent” identifiers are often used as functional identifiers; see ISO 81346-2 Table 1

ISO 81346-1 was created to help standardize this process; the full name of the document is:Structuring principles and reference designations for Industrial systems, installations and equipment and industrial products

The standard (81346-1) does not mandate what designators you should use but it does encourage the use of the standard identifiers found in 81346-2.

The choice of identifiers is left to the design team and in many situations there are other influences that can impact the desired identifiers that include corporate legacy codes, industry standards and common conventions as well as many others.

It should also be mentioned that in certain types of  systems the process flow should also be considered. If I were to consider two very different systems; a large boiler and a bottling line for example, in my mind I will quickly see two very different process flow diagrams. The one for the boiler will be very centralized (generic) with many functional sub systems surrounding the central boiler vessel. The bottling line on the other hand will be very sequential, Raw materials at the beginning followed by several process stations and then the end of line packaging.

Since the boiler plant is centralized it would be my inclination to prefer an identification system that uses a letter code from 81346-2 table 1 followed by an incremental counter, the letter code will identify the general function of the sub-system and the incremental counter will allow you to keep track of many functionally similar sub systems. Also the fewer letters the easier it is to remember what it is.


=G1: Electrical Power System

=W1: Material Handling Station 1

=C1: Ingredients Storage system 1

=F1: Fire Suppression system

In the case of the bottling line I would see the very sequential process flow diagram in my mind and I would be inclined to go in a different direction. Since the machine operates in a highly sequential manner I would want to use a numerical identification system. The area where raw materials enter the process flow may be numbered as process stations =100 to =199, the process cells in the middle of the machine might have identifiers such as =500 & =570, and the end of line packaging stations might have identifiers such as =900 & =1500 or whatever makes sense for your machine.

You will also need to consider functional systems that I refer to as infrastructure, these are systems that are part of the building that are also part of your manufacturing line, common examples are; Fire Suppression, Lighting, HVAC, Environmental monitoring, Drainage, Comms Networks and many more. I would also assign identifiers to these systems often using numerals of less than 100 but that’s just my personal preference.


=10: Power Distribution

=30: Building Fire System Circuits

=40: LAN

=100: Ingredients Loading

=207: Ingredients Storage system, Hopper Group 7

=403: Bottle Washer; Line #3

=802: Packaging Robot line #2

We have until now been considering system level designs but I often create machine electrical designs using the same principals.


=10: Power Distribution

=24: 24VDC

=30: ESTOP

=40: PLC

=50: Ethernet

=101: Motor Circuit 1

=105: Motor Circuit 5

=401: Water Chiller 1

=600: Operations Station

You are free to create your own system that makes the most sense for your application, just remember to document what you decided on and include it early in your design for others to reference.

Standard Wire Colors for Electrical Panels

I know that this topic has been discussed in many other forums but I had a conversation with a customer recently that got my blood pressure up so I thought I would take a few moments to write a post and vent..

It is 2020 and some panel designers here in the USA are still making up wire colors? Really??

News flash folks..there are national and international standards where this has all been discussed and decided years ago. Technically speaking you can use just about whatever color you want if you really want to..but why would you? 

Here in the USA the most commonly used standard is the NFPA 79 , this is an electrical standard for industrial machinery. This standard was derived from the NFPA 70 and is referenced in article 670. As of this writing the most current edition of the NFPA 79 is edition 2018 and it gets updated every few years, you can even read the current edition online for FREE, so now you don’t have an excuse for not reading it!

For readers in the rest of the developed world you will want to refer to IEC 60445.

Identification of Conductors

I will direct your attention to section 13.2 which discusses this topic in detail which I will paraphrase here:

Equipment Grounding Conductor
Green or Green with Yellow Stripe
and of course there are several exceptions..

Grounded AC Conductor (N)

White, Gray, and one other that you really should read for yourself in the standard.

Ungrounded AC & DC Power Conductors

Ungrounded AC Control Conductors

Ungrounded DC Control Conductors

Grounded DC Control Circuit Conductor
White with Blue stripe

Now I have seen this in many panels as blue with a white stripe but the standard actually says White with a Blue stripe. I have heard folks complain that this wire is hard to purchase or some other rubbish. Just about any large wire supplier has the ability to provide you with this wire, even if its not on the website, just ask them. Most suppliers will simply load a spool of white MTW into a machine that paints whatever color stripe you want onto the wire. I should also point out that Automation Direct has sold this wire for several years.

Conductors that remain energized when the main supply is disconnected.
(Read the standard for the details)

Ungrounded AC Conductor: Orange

Grounded AC Conductor:White with Orange Stripe

This is one that I have used for ESTOPS that travel from panel to panel. In most cases this will also require special labels on the enclosure door and other considerations. A few years ago the standard also included Yellow but it appears that this has been removed in the current edition which also means the image at the top of the blog is out of date. 

Three Phase

Oh.. but in the place I used to work we used BRN, ORG, YEL for 480VAC and  BLK, RED, BLU for 240VAC.. Sure you still can do what you want but you will need to add a label to the inside of the cabinet warning folks and now your panel has a mash-up of wire colors.  In the NFPA world all power circuits use black wires. Don’t know what voltage they are on sight? Get your meter out and check them first, if you are about to touch them I hope they are 0V. 

One more thing..I know that the installing electricians like to pull the colored wires when installing equipment, this help helps them save time when identifying phase conductors, that is until they get into a pull with more than 5 wires or until they run out of one of the colors, then wires get black very quickly. 

Authority Having Jurisdiction: AHJ

Lets never forget about the AHJ. The definition of which can be found in Annex A,  Section A.3.2.2

This boils down to AHJ = Your Electrical Inspector and/or your Customer. This means that they CAN get what they want and you should always ask them what they expect, do not assume. BUT..ALWAYS mention that there are national standards for this and by adopting them they will simplify the design process, decrease sources of confusion and increase product safety. Yes, I know that its a bit of a sales job, but welcome to reality.

Non Standard Colors

When non-standard wire colors are used they need to be permanently identified with a label on the inside of the electrical cabinet. (NFPA 79

 Still don’t believe me?

I have provided a link below to the NFPA website where you can find a link to the free viewer that they provide.

I will also provide here a link to an excellent design guide that is provided by EATON.


if you don’t like clicking link on strangers websites the URL is here..

Missing Report Pages

So everything was working great just a few minutes ago but something happened and now you can’t see any of your report pages.. they were just there!

Thus begins your OH SHIT moment.. Fear not young Padawan!

A solution is at hand!


The Page Navigator has a page filter, make sure that your is set to NOT ACTIVATED.



Now would be a good time to review the available filters and see what they do, if you like what they do and think that you might want to use them some day, review the name and determine if it makes sense to you. If it takes a few moments for you to look at the name to understand what the filter does, you should consider changing the name.

I will also suggest that if a default page filter does not provide any value to you, you should consider deleting it to avoid moments like this in the future.

Have a great day!