Teaching Motor Controls.

[godspeed81]

I am a Journeyman electrician who has been approached to teach a motor controls class. I know my information very well, but I am looking for tips on teaching this course to first-to-fifth year apprentices. I wish to convey the information in a way that will not be daunting to my students. Thanks so much!

 

[jbartos]

Suggestion: Follow current literature for this trade or vocational schools available on websites, e.g.

http://www.amazon.com

 

[ScottyUK]

The following link was posted in another forum - I can't remember by whom, but the credit is theirs, not mine:

http://www.reliance.com/mtr/mtrthr.htm

Quite a lot of fairly complex theory presented in an eas-to-follow guide. I kept the link for our Techs.

 

[PUMPDESIGNER]

I just had this discussion yesterday with a knowledgeable electrician.
I personally think that the motor stuff should be built into the theory classes immediately after resistive theory is mastered by the student. According to the electrician I spoke with, it seems that most theory ends up by default dealing with the bulk of the electrician's work, resistive circuits. Induction is not taught or impressed sufficiently in theory and in practice because most electricican's do not deal with it often.

In regards to actual controls, (logic), advanced stuff and always "daunting" for most electricians because they are not often asked to provide "logic" wiring. In fact, electricians (engineers also) cannot learn, hold, and properly use control (logic) knowledge well unless they are also allowed or required to use this knowledge frequently, as the old saying goes:
"Use it or Lose it".

My suggestion, an entire course and/or semester dealing with the basic theory of induction, magnetics, heat, etc., and how each idea relates to motors, and the differences these things make in how circuit breakers, wires, and other motor control components work in contrast to resistive circuits.

A few hits on the concepts is a waste of time and effort for the most part, small return on investment. Nothing less than weeks of continuous uninterrupted work will get you what you want, for those people to know it.

PUMPDESIGNER

 

[busbar]

Find a textbook that presents information that is appealing to you and will help you best train your students. A workbook with regular homework tied to textbook content is essential. Pre-PLC versus post-PLC subjects are equally important. Time spent teaching the basics in electromechanical components, ladder diagrams and AC/DC circuits are best thoroughly covered well before introducing PLC fundamentals. Some will {want to} view the job pecking on a keyboard as 99% of the work, but understanding of basic control aspects should not be minimized. In process applications, systematic knowledge of mechanical functions and sequences and how they interact with the ‘electrical side’ should be well understood before a single mouse click.

As far as training methods, the student’s ability to translate what’s on the page to an operational system and the ability for the student to record his work in drawings and text are major objectives.

Not daunting? Repetition, repetition, repetition, repetition…

 

[buzzp]

This link use to be Cutler Hammers but since Eaton bought their division its new home is here:

http://www.eatonelectrical.com/NASA...d=984847516544&Sec=learning&uid=Variables.uid

This is an excellent online tutorial covering different motor control circuits, motors, drives, lots of good easy to understand info. They used to have quizes too. It would definately fill your need for basic info.

 

[Highspeed]

Years ago, I have been through that and I will extend what PUMPDESIGNER was saying .
The very first step I used was to try to make the students love electromagnetism (funny levitation things, magnets in aluminium tubes ....)and know how to use handbooks .
I did not spend a full semester dealing with theory/concept but rather tried to develop a sense of how to deal with the requirements giving a mix of recipies(I am sure you have tons) and background theory (20 years after I remember the recepies of my teachers, for the theory, my brain getting older every day, I look at the handbooks or search the web) .
Good luck
HS

 

[pablo02]

I don't know what you're using for materials, but you might look at some of the publications from Barks Publications in Chicago (this is not meant as an indorsement, there are other fine publications available)

http://store.yahoo.com/barksbooks/6060.html

http://www.barks.com/

They used to publish a samll pocket-sized booklet "Basic Alternating Current Control Diagrams" that would be a great handout... I think this is the current version --

http://store.yahoo.com/barksbooks/6087.html

 

[godspeed81]

Thank you folks for all of your advice. I found it very helpful. As a first time teacher, it is great to have such a knowledgeable community to draw ideas from!

godspeed81

 

[jbartos]

Suggestion: Visit

http://www.cutler-hammer.eaton.com/unsecure/html/101bas...

for: Cutler-Hammer motor theory etc. links
It is very informative

 

[Marke]

Hello godspeed81

My experience of moving around the industry and being heavily involved with the starting aspects of motor control, has shown a severe deficiency in our education systems. I know that in my journey through as a student, we covered lots of formula, lots of magnetics theories etc, but never covered the real grit of how a motor operates and especially, nothing at all on starting of machines. Every motor needs to be started. All motor designs are different and have different characteristics. Likewise, many loads have different starting requirements. The correct selection of motor and starting method is important if the optimum starting characteristics are to be achieved.
Some have commented on my "intuitive" approach to describing characteristics. This comes from my experience of trying to get the message across effectively to numbers of students.
I suppose, if I have one suggestion, it is to keep the studies focused on the practical implications and to not get lost in the accademic fascinations. Not everybody is going to be a motor designer, but most will apply motors and be faced with trying to start machines with difficult loads and/or poor supply conditions.
- I have developed my web site to answer many of the practical questions that I have been asked.

Best regards

Mark Empson

http://www.lmphotonics.com

 

[HCBFlash]

I've been messing w/ "motor controls" for 20 yrs or so, and I'm a journeyman, master, amin,.... and I'm still flabergasted by the use of the term "motor controls". Some think that it means pushbuttons, limit switches and relays. Others think PLCs. Others think MCCs.

If you can, take your pick. I personally think that to 96% of all apprentice "electricians" PLC programming is irrelevant. In fact even the pushbuttons and relays stuff is quickly fading. Motors themselves, however, don't change a lot. You can spend a lot of time and energy on teaching or understanding electric motors, and know that it won't be obsolete anytime in the forseeable future.