tonights 2391 exam....(10th march 2011)

[lynj]

one thing to say and that is did c&g forget how to be staightforward? felt like some of the questions were half thought......

anyone else take it?

 

[BEDFORD ELECTIC]

Q24 asked for "direct measurement" of the earth electrode resistance so I took it that they wanted the measurement taking in the same way you would gain a Ze, diconnect earthing conductor so on. the more I watch this thread, the more I think everyone has a different take on the questions but like I said, we all know what we're doing in the field, it's just a case of proving it to the assessors. Good luck.

i think they wanted a drawing of the earth electrode disconected and a mesurement of the ground resistance.
THIS WILL BE A DIRECT MESURMENT OF THE EARTH ELECTRODE.

Q) if you do a P.E.F.C or P.S.C.C test on the installation, and there was a problem with the earthing electrode (resictance)....and the mariner ground was wet !!!

A) you will electricute all the people in the garden (K.A fault current)

.....................THINK ABOUT IT..................

 

[IQ Electrical]

i think they wanted a drawing of the earth electrode disconected and a mesurement of the ground resistance.
THIS WILL BE A DIRECT MESURMENT OF THE EARTH ELECTRODE.

Q) if you do a P.E.F.C or P.S.C.C test on the installation, and there was a problem with the earthing electrode (resictance)....and the mariner ground was wet !!!

A) you will electricute all the people in the garden (K.A fault current)

.....................THINK ABOUT IT..................

Can you show me where these additional earth electrode testing procedures are documented?
In City & Guilds land you assume that the earth electrode was suitably selected and erected!

The only 'direct measurement' of an earth electrode is by use of an earth loop impedance tester-the clue is the word 'direct'

 

[Deleted member 26818]

I think I would have to disagree with you IQ.
To my mind, direct measurement of an earth electrode resistance would be with an earth electrode resistance tester, and would only involve the earth electrode.
When testing with an EFLI tester, you would be testing the EFLI and would involve the line conductor.

 

[IQ Electrical]

I think I would have to disagree with you IQ.
To my mind, direct measurement of an earth electrode resistance would be with an earth electrode resistance tester, and would only involve the earth electrode.
When testing with an EFLI tester, you would be testing the EFLI and would involve the line conductor.

I see your point but I'd point you to Guidance Note 3 (the basis of 2391-10) 2.7.12

"when measuring earth electrode resistances to earth where low values are required, as in the earthing of a neutral point of a transformer or generator, test method 1 (earth electrode resistance tester) may be used.


Then you have Guidance Note 3 Test Method 2 (earth loop impedance tester for RCD protected TT installations) Exactly the scenario being discussed.

 

[Deleted member 26818]

Sorry IQ, I didn't realise there was RCD protection.
The threads getting a bit too convoluted for me.

 

[IQ Electrical]

Sorry IQ, I didn't realise there was RCD protection.
The threads getting a bit too convoluted for me.

It's actually a pretty good thread, if a bit diverse at times lol!

 

[brucelee]

yeah would be good if someone had forgot to hand a copy in then we could all see the questions as they were written as with C&G the exam is in the wording

 

[IQ Electrical]

yeah would be good if someone had forgot to hand a copy in then we could all see the questions as they were written as with C&G the exam is in the wording

Yes, I've asked 2 or 3 times in this thread-the problem is that a seemingly minor detail missing from the question can result in an entirely different answer!

Not that you need to worry Bruce, sitting with the certificate that took 6 months to arrive!

 

[Paul.M]

Unfortunately I was sitting at the back of the room too close to the examiner to take a photo and no chance of accidentally picking a copy up. Wish I did now after the confusion on this thread about what wording is correct for the questions.

Oh well I've got the practical exam in the morning. At least wires and cables don't misinterpretate the truth.

 

[Deleted member 26818]

Good luck, and remember don't stop looking when you've found the required number of faults. Half of them will probably be accidental.

 

[IQ Electrical]

Yes, good luck, above all, be safe-the majority of practical exam failures involve safety!

 

[IQ Electrical]

Post above deleted

 

[brucelee]

safely isolate, lock off, label and retain key in pocket not tool box or fail as a result and check for dead with approved GS38 voltage indicator then check tester on proving unit or known supply to prove working at time of test then re - check for dead

 

[honda127]

yes it did paul well spotted, that just came to me as i read your thread

 

[brucelee]

Unfortunately I was sitting at the back of the room too close to the examiner to take a photo and no chance of accidentally picking a copy up. Wish I did now after the confusion on this thread about what wording is correct for the questions.

Oh well I've got the practical exam in the morning. At least wires and cables don't misinterpretate the truth.

GOOD LUCK paul
with the practical dont rush to much just think about what you doing its not as bad as you think but the waiting to do it is the worst work methodically