Industry Standard Discrepancies

[Clayts]

I have issues with the EWRB and their exams full of wrong answers expected, based on false information taught.

 

There have been gaps and misunderstandings in my knowledge due to personal confusion between what is “in the books” and what I see in reality!.

 

ie: If you are ever asked to sketch a single phase cap start motor, you must have the centrifugal switch on the supply side of start winding. I guess the reason being is that little potential voltage will exist between earth and run and the start winding. Makes sense yes!

 

In reality having disassembled, reverse engineered , wound and fixed hundreds of 1phase motors, I have seen ONE wired like this. The common is ALWAYS on the phase the C/S and cap are ALWAYS on neutral return after start winding.

 

If they teach it. Why don’t they regulate it?

 

Another example

 

They always refer to thirmisters as though they where microtherms. There is a HUGE difference. A Microtherm is a small bi-metal device that will operate to open the circuit when a certain temperature is met due to over current over a length of time. Microtherms are in series with the motor windings.

 

Thirmisters (at least the ones I know of) normally come as three small silicon devices (one for each phase) that act in a similar function as a PT100 . They have a temperature co-efficient and are not designed to physically disconnect the supply …only as a transducer as such. Try and wire them up in series with the windings and your in a whole lot of trouble.

 

If I draw a single phase motor the way they are manufactured and distributed to the world (including NZ), I get ZERO marks.

 

If I use the word Microtherm instead of thirmister, I get ZERO marks.

 

This is only two examples, I have many more.

 

Have I unnecessarily complicated things again?, or maybe I am incorrect? Does anybody have anything to say about this?

 

Clayts

 

 

 

[marke]

Hello Clayts

All I can say, is welcome to the real world.

I am afraid that I am somewhat cynical when it comes to some of the teaching institues and what is taught, if you learn the basic priciples, then you can apply those outside, but some of the detail does not apply in the way in which it is taught.

 

 

I too have been marked down in exams where I have used the "industry standard" answer to a question rather than the "Taught answer". The problem is, particularly these days, things are moving fast and the educators have difficulty in keeping up to date with curent practices. In many situation, there are many ways of doing things, each with their own merits, but industry tends to standardise on only one or two and these may not be the ideal from an educatio perpective.

 

You need to wear two hats, one for schol, and one for the real world. Make sure that you wear the school hat while learning.

 

One of my favourite sayings, is that "your qualifications are just a license to start learning". Getting qualified and passing exams does not make you an expert!! and very often what we learn in the field is rather different than in the classroom.

 

Best regards,