RECENT C & G 2382 question

[ebee]

I did not like this one:-

Where PME conditions apply the main bonding conductor should be -

A/ Half the c.s.a of the earth conductor to Table 54.8

B/ Selected in accordance with the supply neutral to Table 54.8

C/ Determined after consultation with the consumer

D/ Determined after consultation with the supply undertaking.

Comments please .

(Tin hat on head and ducking now)

-------------------------
Space - The Final Front Ear

 

[EFLImpudence]

They're only easy if you know the answer.

 

[RF Lighting]

I suppose technically it's D, but in reality it's going to be B.

I see your point. The wording of the question and answers makes it difficult to be certain you have picked the answer they are hoping for.

 

[ebee]

RF you got it in one.
It really was a question I got last month in the exam so I answered D but then complained to C & G about the poor quality of the question because I knew they wanted B.

Thing that annoyed Me is that some poor soul could have answered D and might have failed the exam

 

[RF Lighting]

That really is very poor.

Even with your books infront of you it's difficult to see which is the proper correct answer.

Did you hear anything back from C&G?

I'm not sure if I've changed my mind now.

The supply company should tell you if there are any special requirements for PEB sizing with their supply, assuming it's a new supply which you've ordered, so there the answer would be B

But, if you are working on an existing supply, or someone else has ordered it, and you've had no contact with the DNO lads, then it shoud be B once you have done D and they have confirmed they are happy for you to do B

 

[ebee]

Yes they waffled about feeding it back thru the tutor but i'd already shown the Tutor who saw my point and ran it thru his other tutor friends. They were split 50/50.

obviously they are looking for B but the note on the table confirms that if DNO has requirments over BS7671 then DNO shall prevail because it is paramount.

So If DNO has a bigger conductor requirement then the answer is D not B but if they do not then the answer is B.
In any event you gotta ask the DNO to know the answer.

What they shoulda asked is "providing the supply authority has no overiding requirement then, ........................." .

poor quality of question, you pay good money for the course and exam and thgey let you down with this question.

 

[dingbat]

No, no , no!

(Edited to add

No, no, no, no, no, no, noooooooooo!!

It's a question about BS 7671 and if you read the wording of the question and of the relevant regulation on page 134 it is not ambiguous at all.

The incorrect wording of answer d) when compared to the note to table 54.8 is the clue that this answer is the deliberate detractor. You're talking about consulting the DNO yet no such answer is offered up.

What worries me is that so many were apoplectic about this on the IET forum. I repeat, there is nothing ambiguous about this question and the answer is clear as day.

There is one cardinal rule with examination questions...

RTFQ x 2

Then RTFQ again.

(Don't make up your own questions!)

 

[ebee]

YES it is a question about BS 7671 and BS7671 tells us the answer is B unless the DNO overrule it then you must follow the DNO, therefore following the DNO is explicit in BS 7671 so the answer can only be D

 

[RF Lighting]

In that case the answer is none of the above.

If you say it is not D because the wording is wrong, then it can't be any of the answers.

B is wrong because you can't just size the PEB conductor from table 54.8, unless you know for certain that the DNO has no overriding requirements, which you couldn't know with out consulting them.

 

[dingbat]

YES it is a question about BS 7671 and BS7671 tells us the answer is B unless the DNO overrule it then you must follow the DNO, therefore following the DNO is explicit in BS 7671 so the answer can only be D

Ebee.

Read the question.

Then read the answers.

Match the words.

Answer D uses a form of words that mean nothing. It is a detractor answer.

I really don't understand why you can't see it.

(Or maybe 'supply undertaking' means something to you?)

 

[dingbat]

B is wrong because you can't just size the PEB conductor from table 54.8, unless you know for certain that the DNO has no overriding requirements, which you couldn't know with out consulting them.

Now you are writing both your own question AND your own regulations.

 

[Taylortwocities]

Now you are writing both your own question AND your own regulations.

But Holmslaw has not contributed to this topic, as yet

 

[holmslaw]

...

 

[ebee]

Absolutely but as you are only allowed one answer not 2 then D must be considered in every example.
B only occours if D gives result that DNO do not insiste on a bigger conductor.

 

[holmslaw]

..