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SPARKS Blog: Who needs knowledge?

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In our latest blog, Mike Davies, SPARKS’ Technical Advisor and retired lecturer, tells us why technical knowledge is essential.

The other day I read a review of a recent TV programme about schools. In the piece, it was said that one pupil ‘hates science with a passion’ and felt he wasted time on Pythagoras. The pupil actually achieved three GCSEs (it didn’t say what they were) and had got his place on an electrical installation course.

So what’s my point?

Being an electrician is not just a case of installing cables, connecting accessories and equipment then switching on the power.

The electrical installation course mentioned in the review will require the student/apprentice to gain a high level of technical knowledge as this is an essential part of being a qualified electrician.

In fact, an NVQ Level 3 Diploma must be achieved and this involves practical ability and technical knowledge including science and the application of basic mathematics, and Pythagoras.

Why do I need to understand science?

Let me give you some examples where science and mathematics are used.

You are required to install a 9.5kW 230V electric shower in the bathroom of a house, what do you need to know?

First of all, you need to order the accessories etc., and you need to know what rating the RCBO is to be. How do you determine this?

Maybe the technical information that comes with the shower will tell you, or you might need to apply mathematics and work it out?

Secondly what cable size should be ordered? Is 4mm² or 6mm² PVC, PVC, T&E cable to be used? How do you find out?

This is where technical knowledge is essential.

Why do we need to apply rating factors for ambient temperature, grouping of cables, thermal insulation etc., when calculating a suitable cable size for a circuit?

Take another example. You need to connect a three-phase electric motor but there is no wiring/connection diagram, what do you do?

Perhaps you could go online and spend time trying to find the wiring diagram or be practical and measure the motor winding resistances with an Ohmmeter.

This will allow you apply your technical knowledge of three-phase electric motors and be able to connect the motor.

While I am talking about resistance and Ohms, take the testing of electrical circuits – how do you know that the test results you are achieving are satisfactory or not without knowledge of Ohms Law?

A low reading of a cables insulation resistance may be due to a fault but it could be a fact that the cable is physically very long.

So, what about Pythagoras, is it a waste of time?

Another example; a cable supplying a floodlight is to be buried underground in a diagonal route across a field. You have the length and width of the field but not the distance diagonally, how do you calculate this diagonal distance? Here Pythagoras Theorem can be used practically.

sparks blog mike davies pythagoras theorem

So is technical knowledge essential in the day to day role of the qualified electrician?

Yes it is and this is why the qualification has a minimum Level 3 requirement.

Don’t ‘hate science with a passion’ – science is a key component of your chosen profession.

Previous SPARKS Blogs

“But, I thought…”

Legal status and qualifications

Cable strapping and good workmanship

The Big Renewable Power Charge!

A guide to floodlights

Get smart – hire an apprentice

I’m Reg and I’m here to help you!

EV Charging and the 18th Edition

Other News