Electricity 100

[brian john]

This forum serves an important function in the furthering the knowledge of tradesmen and others and I have always been of the philosophy of ?The only dumb question is an unasked question?.

BUT sometimes, some of the questions/post are so basic, so Electricity 100 yet in many cases these questions come from licensed (and unlicensed) electricians and masters. I am by no way on the high end of the scale in my electrical/code knowledge and am far from a code/electrical expert like many of the off the top of the head members of this forum.

Has the apprenticeship system, licensing, OJT just fallen down, do we need to do more? Some of the post are downright scary, the ongoing practices and lack of safe work practices, lack of basic electrical knowledge, lack of code basics.

I am not picking on anyone and I also realize that many of us are in one aspect of the trade...Strictly residential and need some help with the occasional commercial job and vice a versa. I would also prefer these guys ask these questions as it is better to be safe than sorry and they are trying to learn, plus what else would I do with my evenings reading all the questions and answers.

 

[iwire]

Brian honestly I think you expect far to much. Your 'niche' is so different from the work being done by the large majority of electrical contractors I don't think it is even remotely fair to judge the rest of the trade from where you are.

The majority of ECs are small shops with no formal training and little money or time to provide it.

You see all the screw ups, that is the nature of your business, but the majority of work is not screwed up. It's like what happens to cops, they only see the bad side of people and begin to think everyone is bad.

The same happens here people don't bother to post about things they know, they only post about things they do not know, or have screwed up.

 

[Lxnxjxhx]

questions/post are so basic

questions/post are so basic

What people need to learn or know or remember on a day-to-day basis will be learned or known or remembered.

 

[480sparky]

Personally, I think it's because this trade is so far-reaching it's impossible to know everything about all areas.

We're electricians, and our scope covers 120v wiring in houses to 100kv line work. Data, video, POTS, Cat5, fiber optic, alarms, intercoms all fall to us to do.

Most people don't know the difference between a lineman and a 1-st year residential apprentice. Both can be equally capable, smart and able to do their job well, but what they do is so different. An 'electrician' may be able to walk into a large manufacturing plant and troubleshoot, repair and verify operation on a 4160v PLC motor control unit, but have not the foggiest idea how far to staple NM from a 1900 box.

Think of a plumber, and what do they do? Hot, cold, waste & vent. Occasionally, on large commercial jobs, maybe a recirculation line. Every see a plumber do a fire-sprinkler system? How about a fountain, or a swimming pool? Lawn irrigation?

 

[bikeindy]

Brian, I am a firm believer in "there are dumb questions" When I was in tech school for electronics there was a guy who asked the instructor, "How do the electrons 'know' which way to go?" The instructor tried very hard to explain how electron flow worked but this guy just couldn't get past how the electrons "knew" which way to go. When he tried to explain in in terms of plumbing it only made the guy wonder how water "knew" which way to go. There are dumb questions, they are generally asked by dumb people. that said I don't see any dumb questions on this forum I am with Iwire and 480sparky. My first day on the job for an EC I didn't have a clue what a single gang nail-on was, but I could have repaired a LASER targeting pod on an A-10.

 

[cowboyjwc]

I agree that most of us have our own niche or comfort level, but I will say that, since Brian asked, that I do believe that there is no apprentiship training.

In my area, from what I hear, there is only one trade school at this time, from here it would be like a 2 hour drive one way. So how do you work all day then drive to school and drive home and still find time to sleep and eat?

I think to that too many contractors are only worried about how much money you can make them, there are still a few, but my guess would be not as many, that look for that spark in someone and take them under their wing and show them the ropes. I mean take them out, work side by side with them for the year or two it will take to get them up to speed and really teach them.

I think Brian see's a lot of what we see as inspectors. If contractors are out there saying look at the poor quality of work I see, you can mulitiply that 5 times or more, of what I see.

 

[zog]

Brian, I am a firm believer in "there are dumb questions" When I was in tech school for electronics there was a guy who asked the instructor, "How do the electrons 'know' which way to go?" The instructor tried very hard to explain how electron flow worked but this guy just couldn't get past how the electrons "knew" which way to go. When he tried to explain in in terms of plumbing it only made the guy wonder how water "knew" which way to go. There are dumb questions, they are generally asked by dumb people. that said I don't see any dumb questions on this forum I am with Iwire and 480sparky. My first day on the job for an EC I didn't have a clue what a single gang nail-on was, but I could have repaired a LASER targeting pod on an A-10.

Electrons dont flow, they transfer thier energy, common misconception from 1940's electrical theory books.

 

[zog]

I am wih brian on this one, yes the equipment Brian and i work on is different and no one can know everything about everything electrical but all of us should know basic eletrical theory. For 14 years I taught courses to electricians (Among other groups) and I have always been amazed at the lack of knowledge of basic electrical theory by most eletricians out there.

Actually I think the younger guys coming out of school today have stronger knowledge bases of theory than the 20-30 yr J-man out there, the IBEW and other orgs are doing a better job on that IMO, but the hands on skills and equipment knowledge seems weak, I guess the idea is teach the theory, learn about the equipment you need to learn about OJT.

Now most of the older guys I trained knew the theory once, but have forgotten most of it because no company is going to send a senior guy to basic theory classes, so I always slipped it in to all of my courses to freshen the memories up.

Everyone should know how to calculate FLA on the secondary of a 3 phase transformer given kVA and secondary voltage (Only around 20% correct on my post tests), everyone should know what reactive load and Pf are (Around 10% correct), or how to do very basic series and paralell ckt calcs (Around 50% and 5% correct.

Like brian I am not picking on anyone, more of observations from training classes than this forum really.

Dont believe me, go to this link, take this very basic theory quiz, and see what you get (The first time). Feel free to post scores. (Be honest), now I expect many active members to do very well on this quiz, have your guys at work take it and see how they do.

http://www.electricaltrainingservices.com/online_assessment_tests.php#BasicElec

Click on Basic Electricity to take quiz

 

[cowboyjwc]

Electrons dont flow, they transfer thier energy, common misconception from 1940's electrical theory books.

I still run my pipe down hill, just in case.

 

[zog]

Now take the others, if you cant pass breakers, you shouldnt be messing with LVCB's, cant pass substation I, stay out of substations, etc. Pass all tests without cheating on the 1st try, PM me a resume.

 

[brian john]

What about the inspectors on the forum do you see common mistakes over and over for basic NEC issues. Stuff one would expect an electrician to know?

I do agree with Bob and others about you know what you work on...But I am saying guys that do not know what they work on, not just in the construction end but service sector.

And I also know the brain only retains so much in active memory, you retain what you need and lose or place on the back burner stuff you rarely use/see/do.

Available current from a transformer when all you have is kva.

Molded case CB tripping from overload and they are adjusting the instantaneous.

 

[cadpoint]

What about the inspectors on the forum do you see common mistakes over and over for basic NEC issues. Stuff one would expect an electrician to know?

It's a my liberty and I'm glad I'm not the only one that's eat up with this place...
(wait you editted something, Maybe ...)

I do agree with Bob and others about you know what you work on...But I am saying guys that do not know what they work on, not just in the construction end but service sector.

You most have found Zog's safety overview on live work!

And I also know the brain only retains so much in active memory, you retain what you need and lose or place on the back burner stuff you rarely use/see/do.

No , I don't agree, the mind should be exercized just like everything else/

Available current from a transformer when all you have is kva.

Is this code :smile:

Molded case CB tripping from overload and they are adjusting the instantaneous.

That is a problem ...

I find that some in the trade don't worry of have to worry about the application of the device, but only grasp the how to get it there.
That moderate sum of work is more of a baseline of this vocation for alot of people, the code even enforces it being that its the minimum.

I find that alot of people don't realize the scope of work that underlines our vocation, and with-in our own ranks as well, much less the general public.

I have some very strong thoughts about the lack of, some commentors at times, I frankly always fine it interesting who might answer, WHAT!

It is MY privilege to enjoy the candor expressed here !
Even if only the minimum ...

 

[bikeindy]

Electrons dont flow, they transfer thier energy, common misconception from 1940's electrical theory books.

Really are you sure it isin't this?

Electron Flow:
Electrical current is the flow of electrons. It is produced when an electron from one atom knocks electrons of another atom out of orbit. When an atom contains only one valence electron, that electron is easily given up when struck by another electron. The striking electron gives its energy to the electron being struck. The striking electron settles into orbit around the atom, and the electron that was struck moves off to strike another electron. This same effect in the game of pool. If the moving cue ball strikes a stationary ball. The stationary ball then moves off with the most of the cue ball's energy, and the cue ball stops moving. The stationary ball did not move off with all the energy of the cue ball. It moved off with most of the energy of the cue ball. Some of the cue ball's energy was lost to heat when it struck the stationary ball. Some energy is also lost when one electron strikes another. That is why a wire heats when current flows through it. If too much current flows through a wire, overheating will damage the wire and possibly become a fire hazard.

If an atom containing two valence electrons is struck by a moving electron, the energy of the striking electron will be divided between the two valence electrons. If the valence electrons are knocked out of orbit, they will contain only half the energy of the striking electron. This effect can also be seen in the game of pool. If a moving cue ball strikes two stationary balls at the same time, the energy of the cue ball is divided between the two stationary balls. Both stationary balls will move, but with only half of the cue ball.

 

[jcole]

Scored an 88% on that assessment test that was posted. Am I the only nerd that took it? No books No calculators, Lets compare!

 

[zog]

Really are you sure it isin't this?

Electron Flow:
Electrical current is the flow of electrons. It is produced when an electron from one atom knocks electrons of another atom out of orbit. When an atom contains only one valence electron, that electron is easily given up when struck by another electron. The striking electron gives its energy to the electron being struck. The striking electron settles into orbit around the atom, and the electron that was struck moves off to strike another electron. This same effect in the game of pool. If the moving cue ball strikes a stationary ball. The stationary ball then moves off with the most of the cue ball's energy, and the cue ball stops moving. The stationary ball did not move off with all the energy of the cue ball. It moved off with most of the energy of the cue ball. Some of the cue ball's energy was lost to heat when it struck the stationary ball. Some energy is also lost when one electron strikes another. That is why a wire heats when current flows through it. If too much current flows through a wire, overheating will damage the wire and possibly become a fire hazard.

If an atom containing two valence electrons is struck by a moving electron, the energy of the striking electron will be divided between the two valence electrons. If the valence electrons are knocked out of orbit, they will contain only half the energy of the striking electron. This effect can also be seen in the game of pool. If a moving cue ball strikes two stationary balls at the same time, the energy of the cue ball is divided between the two stationary balls. Both stationary balls will move, but with only half of the cue ball.

that is exactly it (Where did you find that) I shot some video of pool balls that I used in my clases to explain this concept, to tweak the analogy you posted the balls would all be lined up in a line with little space between them, the energy in transfered very quickly (Near the speed of light in the case of current flow) but the relative motion of the balls (or electrons) is minimal.

Guess I should have been clearer in my post, electrons do not "Flow" at the speed of light along a wire as was once believed, the energy transfered is what "flows" near the speed of light.

 

[zog]

Scored an 88% on that assessment test that was posted. Am I the only nerd that took it? No books No calculators, Lets compare!

Well done, I think the people that do take it and post thier results, will do fairly well, many others will not tkae it or not do as well as they thought and move on to the next thread. Perhaps a poll is in order

 

[Ed Carr]

Zog..I scored a 70...def not stellar

 

[zog]

Ed and Jcole, i opened a new thread with a poll for results

 

[resistance]

Brian honestly I think you expect far to much. Your 'niche' is so different from the work being done by the large majority of electrical contractors I don't think it is even remotely fair to judge the rest of the trade from where you are.

The majority of ECs are small shops with no formal training and little money or time to provide it.

You see all the screw ups, that is the nature of your business, but the majority of work is not screwed up. It's like what happens to cops, they only see the bad side of people and begin to think everyone is bad.

The same happens here people don't bother to post about things they know, they only post about things they do not know, or have screwed up.

Well said!

 

[480sparky]

....Guess I should have been clearer in my post, electrons do not "Flow" at the speed of light along a wire as was once believed, the energy transfered is what "flows" near the speed of light.

Trivia question: At one amp, how many electrons 'flow' past a given point?