What is Current?

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You may never have had to think about this but:: what is current? In the main we know that our appliances will not work if there is no current,  but could you tell someone what it is?  This dilemma occurs because although we easily recognize the effect of electric current namely, heating, lighting, and magnetism, we cannot tell what it is?

In order to illustrate, It is easier to compare the flow of current with something physical like water coming out of a tap because we can see it.  Water flows in the pipework supplying a tap in a similar way as current in a conductor.  This flow is made up of the drift of electrons from one part in the circuit to the next when 6241000000000000000000 charged units (Coulombs) pass a particular point in the circuit in one second, it is said that 1 Ampere has flowed.  Generally we refer to the flow of electrical charge in Amps, which as you can tell from the number of zeros makes it easier to quantify.  So the flow of electrical charge from the consumer unit to the piece of equipment giving heat, light and electromagnetic force is called current.

 

What is Voltage?

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Sometimes things are so evident that the need to describe them appears pointless-hidden in plain site.  This seems to be true of things like oxygen.  I mean, when was the last time you heard an ordinary person say: “Oxygen is used by living organisms to support life and for the oxidation of food.  It is also a very important element of the periodic table.”  Now I am certain there is someone out there who is saying well actually, just last night…Let me stop you there, because it is quite clear the inclusion of the word “ordinary” escaped your attention.
The word voltage also has this mantal of invisibility even for professional engineers.  Since it cannot be seen one of he easiest ways of defining voltage is by comparing it to something visible like a bathroom tap.  The water flowing out of the tap is forced out under pressure when the faucet is opened.  This force driving out the water can be likened to voltage in an electrical system which drives the electrons before it.

 

What do the new codes in the EICR mean?

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It cannot of past your attention that the 17th Edition Green book came out in July 2011 and came into force in January 2012.  One if the things  that as been remarkably changed is the testing certificates.  There is now a schedule of inspections that relates specifically to periodic inspections.  This inspection schedule is remarkably like the check list from a cars MOT visit and consists of two A4 sized sheets filled with items to be inspected and checked.  There are three codes associated with the findings:

  • C1 Danger present risk of injury, immediate remedial action required
  • C2 Potentially dangerous, urgent remedial action required
  • C3 Improvement recommended

Any observation given a C1 or C2 code should result in the overall condition of the installation being reported as unsatisfactory.

Anyone want a Free 17th Edition Course?

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Hands up anyone who wants to attend a free 17th Edition Amendment course. Mastech Training Limited has a training event booked on 13th January 2012. This will be a breakfast event lasting from 8.30am till 10.00 am. This session will give a brief overview on the Amendment 1 of the 17th Edition July 2011. All delegates will receive an attendance certificate as evidence of their CPD. To confirm your place contact Mastech Training Ltd.

Mastech Training Ltd
205 Kings Road
Tyseley
Birmingham
B11 2AA

0121 707 2727

Gadget too Rules Inspector

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The average household owns three times the amount of gadgets that they did 20 years. In a recent report it was stated that this increase has provoked concern that this will place a strain on the nations energy resources. The main culprits seem to be the nations favourites plasma TV, and giant freezer
Fairgate House
205 Kings Road
Tyseley
B11 2AA

Is Britain going Solar Mad for 2012

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With electrical energy scheduled to take another hike in price and some people deciding whether they are going to heat or eat this winter, it is little wonder that the appearence of solar pv units is more common place now. But the question is whether or not the British are going to go solar mad for 2012! The thing is that the current level of FITs payment is due to be reduced in 2012 so that anyone wishing to take advantage of the government payments for the produce from pv units must act now to get the most out of their investment. So there may well be a mad scramble to opt in over the next few months from customers to installers and suppliers there is the potential that all will feel the rush to make it in. If you want to be a PV installer contact us at Mastech Training Ltd.

Mastech Training Ltd
205 Kings Road
Tyseley
Birmingham
B11 2AA

0121 707 2727
http://www.mastechtraining.com/

What to Do About Crazy Readings?

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>It happens to all of us from time to time, you think you know what the readings should be, and bang out of the blue your instruments starts speaking a different language. The first thing to say is that your instrument may in fact be giving the correct reading and it may reveal that something is wrong with the installation. Failling that though, it is worth bearing in mind that atmospheric conditions such as heat, cold, and damp influence what your meter tells you. Next time your meter goes south, check whether or not there have been problems with things like rats that are quite partial to pvc cable.

A word of warning though do not assume the worst, some of the basic things are equal contributors to error. Ask yourself, is the instrument properly calibrated, do the batteries or the instrument leads need replacing, it is always worth carrying extra leads and batteries for this exact reason. Finally, user error the faulty object may in fact be you, READ THE INSTRUCTIONS-enough said!

Mastech Training Ltd
Fairgate House
205 Kings Road
Tyseley
B11 2AA

0121 707 2727
www.mastechtraining.com

What To Look For During Periodic Inspections

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>One of the things that make the 2391 difficult to pass is that the use of language has to correspond to BS7671 and Guidance Note 3 (GN3). GN3 in particular refers to factors that need to be investigated during the periodic testing. The phrase SADCOW will provide an easy framework for remembering the various elements: S-Safety, A-Age, D-Deterioration, C-Corrosion, O-Overloading, W-Wear and Tear.

Mastech Training Ltd

Fairgate House

205 Kings Road

Tyseley

Birmingham

West Midlands

0121 707 2727

www.mastechtraining.com

What is the Zs Rule of Thumb?

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One fact that is kind of invisible is the 0.8 rule of thumb value which needs to be taken into account when testing the loop impedance of circuits. The values displayed in the 17th Edition Regulations do not take into consideration temperature and loading so do not give and accurate sounding of what the final Loop Impedance Zs should be. These values then need to be multiplied by the 0.8 figure in order to adjust them for the “in situ” conditions of temperature and loading.

Mastech Training Limited
Fairgate House
205 Kings Road
Tyseley
B11 2AA

0121 707 2727
www.mastechtraining.com

Is the 2391 Exam Ever going to change?

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The 2391 Electrical testing and Verification qualification is held in much fear and dread in the world of the everyday sparkie. The Electrical Contractor Magazine in June 2011 reported the letters of some of its readers on the subject. Strong feelings were aired concerning the relevance of the exam to jobbing electrician especially as he would not normally carry out work on things like Marinas and Agricultural projects-what is the sense of putting them in the paper. Still others said that the qualification is out of date featuring questions from earlier versions of the Regulations which had no relevance at all to the present.

Perhaps surprisingly though, the 2391 does have its fans who say that the job of electrical testing is one that carries so much responsibility. The kind on which peoples lives depend, and could in fact land someone in court. As such it should only be open to the best of the best. So, I hear you ask is there going to be any changes? Well yes there is, and it may not be to every-bodies liking. Although all may not be told here there are proposals afoot to slice the course up into several units which will require electricians to update according to their specialty every two years. it might also be the case that individuals with complete qualification can inspect and test.

Mastech Training Limited
205 Kings Road
Tyseley
B11 2AA
0121 707 2727
www.mastechtraining.co.uk