Inspection and Testing

I had a candidate come in for his 2392 the other week and when I advised him to test his continuity using the Method 2 (wander lead or R2 method) for his assessment to save time, he said that as he had been shown the R1+R2 test method, that was the method he would use.

Interestingly after he had taken the full allotted time for this assessment he announced that for his 2394 and 2395 assessments he would be using the R2 method!

The IET GN3 gives both methods as valid continuity tests and only favours the Method 1 because in a real-life scenario a wander lead could be inconvenient or worse a trip hazard.

The assessment boards can be covered by the length of the test leads so no wander lead is required so all the terminations can be reached with just the already nulled meter leads. This means that you can test end-to-end on R1, end-to-end on R2 and add them together for an R1+R2 result, and you've not disconnected a thing! You will of course have validated your results with a reading of Rn as well.

Of course the Ring Final Circuit will have to have a proper 3 step set of tests.

There is nothing in the C&G assessment guidance that says you have to use the R1+R2 method (Method 1), just that a suitable method is used that garners valid results. I have consulted other assessors on this matter and they agree.

My advice to candidates is if you are not testing a Ring Final Circuit and you have a screwdriver in your hand, ask yourself why as you are about waste more time that you haven't got.

Advice and tips to candidates of the 2394 and 2395 practical assessment

This week I thought a quick word to those about to take the practical assessment part of their 2394 or 2395 inspection and testing course.

Most candidates know what they have to do or at least what they have to do for Task D of the 2394 and Task B of the 2395 (the big test rigs), but are unclear what is expected of them by way of performance.

This is not an easy answer, but I'll try to explain.

Just to reassure you, the assessor is not there to fail you. He is merely there to judge your performance and ensure that you are safe and have the best opportunity to do a good job in a relaxed atmosphere. There is no point in the assessor running the assessment such that the candidate is nervous. So other than at the points in the assessment where power is turned off or on, he's unlikely to be standing behind you breathing down your neck. In fact you should barely be aware of him unless he asks you a question or you need to ask him something.

First and foremost is that you must demonstrate a safe aproach to testing at all times. Of course you will for the most part be working on a dead board so safety during dead testing is virtually a given. Really there are only 2 safety pinch points.

During the initial isolation of the board
Energising the board for the first time

Any safety infraction here will lead to your assessment being halted and will result in a 'referral' on your assessment sheet.

What is meant by a safety infraction? If you fail to complete (leave anything out or fail to apply the correct process) the safety isolation procedure or if during energising the board any of the protective conductors is not connected.

In the event of either of these 2 cases the assessor's instructions from the C&G is quite clear.

The assessor will have an extensive tick sheet to complete so that he can note what you did during your exercise. He will not leave any boxes unticked because he will tap you on the shoulder and suggest that you may have missed something or that you might not have done something that you should have. Similarly if you are not sure how to proceed then you may ask the assessor, but he cannot directly answer your question. He might for example point you to the copies of the regs or on-site guide or GN3 or he may ask you some questions that lead you to your own conclusions.

Don't worry if you make a mistake that is not safety related, everyone does. If you spot the mistake and self correct, that's great as it shows a critical approach to your testing. If you make a mistake and the assessor spots it then expect him to comment and ask you to correct.

Try and repeat tests especially those that are unexptected and verify all your tests on another conductor where possible. For example if you measure an end to end R1 then measure the Rn as well to confirm that the 2 results are substantially the same. This will work for all but lighting circuits that use the 'loop-in' system where the R1 at the ceiling rose will be higher than the Rn which in all cases will be shorter.

When conducting an R1+R2 test there is no reason to combine conductors using method 1. It is perfectly acceptable to test individual conductors and add them together to make up R1+R2 using method 2. This will speed up your testing considerable without compromising on quality.

Try and get as much of the paperwork done before you start testing so that you have for instance all the n/a's in the r1,r2 and rn boxes for circuits that are not ring final circuits so that you dont write results in the wrong boxes. Tippexing your mistakes is less than ideal.

And finally............

It is an exam like any other, so preparation pays huge dividends or to put it another way, it's difficult to pass without substantial revision beforehand.