Industry standards for wiring diagrams 2

[Sparweb]

Hi,
I am updating the electrical diagram templates being used by my company, and noticed that there is no industry standard for drawing interpretation mentioned in the title block. Surprised by this because the structural people like me have been referencing ANSI Y14 forever on structures drawing templates. And actually sticking to it when manufacturing calls me with questions.

So I went to look up the current standards for wiring diagrams and couldn't find an answer. They all seem to be rescinded, expired, or withdrawn.

https://standards.ieee.org/standard/315-1975.html

https://standards.ieee.org/standard/Y32_2-1962.html

https://standards.ieee.org/standard/200-1975.html

Other have asked, no clear answers:

https://www.eng-tips.com/viewthread.cfm?qid=173571

https://www.eng-tips.com/viewthread.cfm?qid=162841

https://www.eng-tips.com/viewthread.cfm?qid=173844

I can't find a replacement on the IEEE website. So where do I go now?

 

[RedSnake]

Hmm not sure if this is what you are after.
No symbols though ..
and really messy

IEC_81346_2_2019_EN
Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations –
Part 2: Classification of objects and codes for classes

Maybe you can look for this IEC TC 3

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[dpc]

If you are referring to one-line (or single-line) diagrams: In the US, there are conventions, but no nationwide standard. "Electrical Diagrams" is a broad term - in some cases there are some industry or equipment-specific standards from NEMA. But if you're looking for universally used standard symbols and layout in the US, you won't find it.

 

[Sparweb]

I have a copy of ANSI Y14.15. That's basically what I'm looking for - but this comes from the 1960's!
Nothing equivalent to that and more current?
(please forgive the pun)

 

[thebard3]

As long as your internal standards allow (as ours do) I tend to use IEC symbols. They are readily available on many websites and you can download AutoCad symbols from some too.

Brad Waybright

The more you know, the more you know you don't know.

 

[cranky108]

IEEE guides are general, but most of us can read them. Most utilities develop their own standards, as ours did, and it is a derivation of the IEEE guide.

 

[waross]

I have looked for standards without success.
Ladder type schematic diagrams are fairly standard, but some have more information than others.
Additional information not found on all drawings:
Line numbers; fairly common.
Wire numbers; optional, may be consecutive, a better scheme is wire numbers tied to line numbers.
eg: Line numbers are multiples of 10 or 100. Wire numbers on each line are consecutive to the line numbers, The first wire on line 100 will be 101, the next wire number will be 102, and so on.
Operator numbers; Each relay coil or contactor coil may have suffix numbers to the right of the right hand vertical line or L2.
The suffix numbers will indicate each line with a contact controlled by that relay or contactor.
Contact subscripts; below each contact may be a number indicating the line containing the operating coil for this contact.
Embedded terminal numbers;
By that I mean the numbers moulded or stamped on a relay adjacent to the terminals.
In many applications it is important which particular terminal or contact set is used in a particular circuit. This is to avoid inadvertent opposite polarity connections.
On many drawings these numbers are shown both to avoid opposite polarity connection and to aid in trouble shooting.
Information with more variety;
Multi contact selector switches and push buttons.
Where the normally open contact and normally closed contact of a two pole contact are on different lines the mechanical connection may be shown with a dotted line.
More complex devices may include a truth table to indicate the individual contact positions at the various switch positions.
Where to use dotted lines versus truth tables? This is a moving target. Different engineering firms and different manufacturers will do this differently.
Power wiring associated with a control schematic; A wide variety of standards.

Boolean; Often a Boolean diagram may be arranged in a similar format to a ladder diagram. I have found these to be quite easy to follow for trouble shooting.

Diagrams incorporating a Programmable Logic Controller or some type of Control Module.
The diagrams that I find the easiest to follow are often arranged with the inputs on one side and the outputs on the other side.
The panel wiring may be shown on one drawing with the PLC of CM shown as a rectangle, and the internal circuit either not shown or shown on a separate drawing.

When I had to draw a schematic diagram I tended to either try to copy the format already in use for the plant in question or to use a format that I had found to be easy to use for trouble shooting.

Anecdote alert: When I was half of the age that I am now and much more than twice as smart, I designed a control panel for an oil heater in a small refinery.
The drawing was fully annotated and the PLC Boolean logic was depicted as a conventional ladder diagram,fully annotated.
The panel was built and put into service with no issues.
Several months later, I left the refinery in Toronto for an extended vacation near Vancouver.
Then the program crashed and the plant went down.
I got a phone call out on the west coast.
The plant was willing to fly me back to Toronto if needed.
I set up another call in an hour or two. On the Toronto end were the plant engineer and the plant instrument mechanic with the prints spread out on the board room table. On my end I had a large supply of paper on the kitchen table.
With the full annotation on the prints, I was able to quite easily reproduce the section of the circuit where the bug was hiding.
Once I had the circuit copied I was able to locate the bug and instruct the instrument mechanic how to connect the programming device and insert one jumper in the Boolean logic.
The plant was back online within an hour.
The point is: Annotation is important.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Sparweb]

That is SOOOOOOOOO not the "aerospace" way of doing things.
Sure, many companies create their own standards, but many engineers from those companies also love sitting on committees with the standards agencies and come up with even more standards.

Anyhow, I found ASME Y14.44-2008, which is what I was looking for.
ASME, not ANSI.

 

[thebard3]

In my many years of work in various industries I have never seen 2 operations with identical standards for electrical drawings/diagrams/schematics. I have my own preferences for how I like to have things arranged and this is the result of years of continuous improvement, or trial-and-error if you will. We make minimal use of pushbuttons, relays, and similar hardware but you are correct about the importance of cross-refencing everything related to a particular device. I almost always use pushbuttons and relays directly connected to PLC I/O so there is very little hard wiring to documnet. So far as dashed lines are concerned, it is usually difficult to place everything on the same sheet so we use a direct reference to all of the locations.
As far as wire numbers are concerned, I have seen drawing sets that began with wire #1, then #2 and #3 respectively. I think wire numbers should mean something and we usually denote the line number of the schematic, except for PLC I/O which uses a number relevant to the I/O address. Prefix of zero indicates output and prefix of 1 indicates input.
SO- I think your question is where and how to use industry standard practice to develop electrical documentation and I would answer that by saying that you probably just have to make it up yourself. When I first started my current job, the company had no documentation standards for anything. Bar napkin sketches were often stuck inside a O&M binder. Being that it is a chemical company, that can be a problem by itself.

Brad Waybright

The more you know, the more you know you don't know.

 

[Sparweb]

Being that it is a chemical company, that can be a problem by itself.

Because... the chemicals involved aren't related to breweries?

Thanks, everyone.

FYI, the notations, wire number codes, and symbols on our drawings are mostly "borrowed" from one specific aircraft OEM. Points for consistency, but outright specifying that OEM's drafting standard on the title block would raise some eyebrows. We need a more universal way to send these drawings to our customers with some expectation that they can interpret them correctly.

 

[FacEngrPE]

ISA5, Documentation of Measurement and Control Instruments and Systems provides some guidance that can be useful. HOWEVER it is best to use some approach that works for your use case.