Wiring diagram  drawing software for ~3kW Power electronics switching units  - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 30, 2021, 08:29:23 pm
content: Hi,We have to do wiring diagrams for ~3kW power electronics switching units with sometimes power control units on them.Eg relays, DIN rail mounted stuff, RCD's circuit breakers, fuses, Looms, etcPower electronics etc.Which is the easiest to learn and use for this?Also, free of charge hopefullyIs there a difference in the way you woudl do it for....1.....Production workers to use as construction diagrams2.....Diagrams to be prepared for possible buyers of the company and its products.3.....Professionals to do fault finding from....i would have thought the above three cases require different types of wiring diagrams?For production staff, i think a professional wiring diagram would be a hindrance?Surely a simple diagram with plenty of pictures, or even assembly videos would be best for a production worker?Lets face it, if a production worker can understand a professional wiring diagram, then they would go off and work as a wiring diagram drawer instead?

author: janoc
author_rank: Super Contributor
timestamp: July 30, 2021, 08:37:42 pm
content: Quote from: Faringdon on July 30, 2021, 08:29:23 pmUm, LOL.You do realize that these things actually often need to be approved by qualified electricians/engineers, follow relevant norms/standards and any deviations could be a major legal problem in case of an accident?I worked on a stupidsimulator(i.e. nothing even touching mains or coming anywhere close to a factory floor) using a replica of a real control panel - and the pile of documentation we have got with that panel, including meticulously drawn every wire, every switch, every contact, everything using the proper DIN symbology (the contractor who made the panel was German) was crazy. And that was just a bunch of lights and switches on a panel, connected to a small PLC with a 24V power supply.Yes, this is what they use and expect. A Youtube-style video for production workers certainly wouldn't cut it. You wouldn't expect house blueprints to be done as "a simple diagram with plenty of pictures, or even assembly videos" because if masons could "understand a professional blueprint, then they would go off and work as an architect/civil engineer instead", right?This stuff isn't designed for PhDs but for production people.Seriously, I follow your posts over the years and I do wonder how the heck you can (still) have a job as a professional engineer ...

author: Faringdon
author_rank: Super Contributor
timestamp: July 31, 2021, 06:46:47 am
content: Thanks, the company i work for have asked for the wiring diagram to be done in Diptrace (which as you know is a PCB layout editor).Would you agree that this would be a mistake?I would have thought it would need to be a proper package with the proper electrical symbols in it?Which is the cheapeast and easiest to use one?

author: janoc
author_rank: Super Contributor
timestamp: July 31, 2021, 10:25:07 am
content: That I don't know, I probably wouldn't use Diptrace for this but some more "mechanically oriented" CAD program for this. They often have packages for drawing wiring looms, cabinets and such, with the proper symbology. In Diptrace you aren't likely to find the required symbols and would need to create everything from scratch.E.g. AutoCAD has such package, AFAIK.Can't really tell you more, I have always been on the receiving end of these things, not the one creating them.

author: Gyro
author_rank: Super Contributor
timestamp: July 31, 2021, 12:36:54 pm
content: A video of Lewden's custom panel assembly facility. Some glimpses of wiring diagrams, but the look a little light on information to me - lacking wiring colours, CSAs Ferrule diameters etc. Presumably they have experienced assemblers and a separate standard reference chart for these, which is common to all...EDIT: Actually it might be an idea to look at subbing out the job to a company like that - doyouknow the IEE wiring regs?

author: H.O
author_rank: Frequent Contributor
timestamp: July 31, 2021, 02:21:39 pm
content: You CAN of course use any generic CAD package or drawing tool (like Visio and what not) and just import (or draw) symbols, put them down and draw lines between them but then you won't have all the nice stuff a package like AutoCAD Electrical or EPLAN gives you.With a such a package the symbols aren't just "dumb" graphics, there's much more to it than that. Automatic insertion of cross-references between, for example, a relay coil and it's associated contacts, automatic generation of reports (Parts list, Connection lists, Terminal strip overviews etc etc), import/export between ECAD and PLC programming tools and so on.The only really free one that springs to mind is QElectrotech. Doing a quick search just turned up one I haven't seen before, called SkyCAD which seems to have a free (stripped down) version available while their more cabable versions seems the be subscription based... There's also DesignSpark Electrical from RS Components but I'm not sure what the deal is there - is it free to just download and install or is there a catch?

author: Faringdon
author_rank: Super Contributor
timestamp: July 31, 2021, 03:09:19 pm
content: QuoteGood point, no i dont...i just know how to size a wire CSA for the current it carries, and check its got the necessary insulation and ZS0H etc.

author: Gyro
author_rank: Super Contributor
timestamp: July 31, 2021, 07:18:33 pm
content: Well worth purchasing a copy of the 18th edition then (I think you can even get it on Amazon!). It covers things like breaker ratings as well as CSAs and other cabinet related stuff, bonding etc. At least it's just one volume, unlike EMC specs.Buying a custom wired assembled cabinet from someone like Lewden (I'm not sure which other manufacturers offer a similar service) might be economical as they make the individual components, so you wouldn't be paying a mark-up on sourcing them individually. I'm sure they would either accept any custom din rail modules and incorporate them, or alternatively leave spaces (and provide wiring) for you to fit them.Edit: Of course it's IET wiring regs these days, not IEE, (BS7671:2018). The On-Site guide is worth having too, it makes sense of some of the gobbledegook.