How to read electrical drawings (i can't)

Shaun12 · Aug 20, 2015

For the past few years i've been working as an installation electrician. Mostly working on industrial sites and projects. We will install wiring, containment, panels and motors. I would say i'm pretty confident with any of that. I passed all of my exams throughout my apprenticeship without an issue and found the AM2 relatively easy.

However, recently whilst on a job we were asked to fault find in a panel that had had a fault on the security circuit for a piece of automated machinery. I was handed a set of drawings and being completely honest i didn't have a clue where to start. I have somehow managed to go through an entire apprenticeship without having to read a drawing to fault find. Luckily for me in this situation, the guy i was working with knew what he was doing so he lead the fault finding.

I guess i have just never faced the situation on site until now. At the moment these drawings might as well be in Japanese. How can i learn in my own time how to read them and be able to fault find using them? Does anyone have any tips or any suggestions on reading material or videos...

I feel pretty embarrassed about this....

edexlab · Aug 21, 2015

I've just tried it and your right it's not working , I just typed in
"reading electrical ladder drawings " to Google and this was an article for

"m ecmweb.com>Basics "

It just shows/explains the format or layout of a ladder diagram ie input/ output devices positions rungs and numbering ,Nc/No contacts might be too basic for you perhaps

Shaun12 · Aug 21, 2015

oh ok. What I'm going to do is get some drawings from work and anything i'm not sure of ask here. I'm sure it will help others as well

Spoon · Aug 21, 2015

rr2 said:
oh ok. What I'm going to do is get some drawings from work and anything i'm not sure of ask here. I'm sure it will help others as well

Good idea.

edexlab · Aug 21, 2015

I'm in the same sort of situation , although I do work in the factory as well as on site, the company here likes you to learn off your own back so I started looking at the drawings doing some research online and trying to figure out what's what,
their drawings are a bit different from conventional drawings and people here are not always forthcoming with information, some are good, but I don’t see them much
but the overall culture is to find out yourself !

The best thing I've done to improve my understanding was to take the drg and trace it through panels referencing the control drgs ( during my lunch ) starting from the incoming isolator all the way through

This made it all make much more sense!

Then I got lucky and got the chance to work on a machine with an engineer

I had to trace through all the circuits and check them against the drawing removing any unecessary modifications (machine was an experimental ) and then redoing it to his design.... this was a really good experience tbh and I feel I'm getting somewhere now