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?

 

[Paul.M]

Yep I've just finished it an hour ago and if I haven't passed it I'll donate £100 to the forums charity. Don't get me wrong, I'm not super smart or highly intelligent but they just kept on asking questions that I knew (well most of them).

Anyway panic over and concentrate on the practical on Wednesday of next week.

Hope everyone that took tonight test knows about TT systems .

Let's see what others say and tell us how they did.

Ps welcome lynj.

 

[lynj]

had a feeling earth electrode testing was going to come up, so i over revised it , also what did you work out as the maximum operating current for 26 a?

 

[john25]

Arrrgh I screwed uyp my TT drawing by drawing the Installation Electrode straight down from the MET Hopefully the Examiner takes pity as I used coloured pencils and Labeled everything up

Anyways I answered all but 2 questions so hopefully I passed.

 

[nockster]

was told by my instructor not to bother too much on TT as it does'nt come up much, ****, ****,****, when's the re-sit lol

 

[LlandrilloSpark]

Yep I did it

Half of the lads did the earth electrode test with a loop meter, half with a earth electrode tester, being an RCD tt system I opted for loop meter, checked after and was told correct, nailed the loop diagram and ir test procedure of the lighting SWA cable only, got RCD wrong as I put 300ms instead of 200ms , section a , very easy, fingers crissed

 

[IQ Electrical]

What was the rcd question, 300ms sounds right to me for 1x test on BS 61008/9

 

[john25]

It was a BS EN 61008-1 RCD which for some strange reason had it in my mind as a 30mA RCD for additional Protection so did a 7 step RCD test procedure for Q26

BS = 200ms

BS EN = 300ms

 

[filrobbo]

I thought that the maximum operating current was worked out as 50v/Ra=in. Is RA not the resistance of the electrode, which was 100 ohms giving an answer of 500mA?????

 

[john25]

lol it was a 10 point question so Automatically assumed it was a 30mA as you only do a couple of tests for the other RCD's no 5X Tests

 

[LlandrilloSpark]

Sorry John I was with u, I put it as 30ma additional and did the 6 tests , can't be 500ma? Surely? Earth electrode was 100 ohm

 

[IQ Electrical]

I thought that the maximum operating current was worked out as 50v/Ra=in. Is RA not the resistance of the electrode, which was 100 ohms giving an answer of 500mA?????

If they were the figures given then you are correct.

Also, there would be no test at 5X I delta n

 

[jimmy_one_ball]

I thought it was well hard! For the IR test I said test between L+N together and cpc @ 250V because of the voltage sensitive photocells! I think I flunked it also the electrode test was it right to say test between disconnected earth conductor to L1 L2 and L3 in turn and record highest as 3phase installation?

 

[nockster]

lol it was a 10 point question so Automatically assumed it was a 30mA as you only do a couple of tests for the other RCD's no 5X Tests

Same as, also did the equation but used the wrong resistance ( I think ) , this is what happens when you take a 8 year break from electrics and the boss dumps you in it !

 

[nockster]

I think u got the IR right, thats what i put, as for earth electrode, kinda sounds right !