2391 written exam last nite

[bobby101]

did the exam last nite i thought the exam was not to bad still quite tough and the dreaded VD question came up by VD i mean voltage drop i think i managed to work it all out but i made the stupid stupid stupid mistake of saying it was within six percent instead of five dont know how heavily i will get penilised for that but was quite impressed with myself for being one of the very few to work it out dont get me wrong i did make a few more schoolboy errors on the exam too but fingers crossed got my practical on mon at 8am aarrgghh had a few beers last nite though how did the rest of you find it and what questions did you think were nuts cause i think there were a few

 

[CRAGS]

Full marks i reckon CRAGS

Hopefully I am going need every mark I can get

 

[Des 56]

Ater the torture of the exam comes the added torture of the long wait for your results
Sorry to remind you all,but good luck to all

 

[jimminick]

I just wish they'd write the exam questions in common english and then we'd probably understand them and give practical answers. I doubt many of us went to Cambridge so why do they try and mislead us in this way...is it to keep the pass % down...or are they just evil? The questions are about a practical exercise we all do on site so the questions should be constructed in a practical, easily understood manner, instead many of them employ uncommon and over-explicit words. We are taking an electrical not an english exam but half the battle is thinking "Am I answering this correctly?"!

Anyone agree or is it just me?

 

[CRAGS]

I just wish they'd write the exam questions in common english and then we'd probably understand them and give practical answers. I doubt many of us went to Cambridge so why do they try and mislead us in this way...is it to keep the pass % down...or are they just evil? The questions are about a practical exercise we all do on site so the questions should be constructed in a practical, easily understood manner, instead many of them employ uncommon and over-explicit words. We are taking an electrical not an english exam but half the battle is thinking "i am answering this correctly?"!

Anyone agree or is it just me?

Spot on

 

[brucelee]

I deffo agree with you mate I thought it was ABOUT inspecting and testing not anagrams or crossword puzzles they are deffinatly trying to mislead us
my writing went to pot so like i had to put as much effort into understanding the questions lets see if they put as much as me into reading it. i could read it but i hope they can

 

[scotsparky]

IMHO the questions are desighned to test if you can interpret faults and have a true understanding of the testing and not just remember answwers. Its a lot to do with interpretation and adaptation. I would happily sit it again but fortunatly dont need top

 

[gaz2212]

i really didnt under stand the first question.... lol... think i put accsesoys comply to bs or equilavent standard... installation complys to bs7671 and not defected as to cause danger,,, or something along those line... any one else remember the question... or what they put???

 

[Charles West]

The question for volts drop went something like this
Determine the volt drop on this circuit and determine if this complies
With the regulations.

A circuit at 20 meters long
2.5mm cable
40 amp supply
7.41 from GN3

Solution:

mΩ/m x L
1000

= 7.41 X 20
1000

=0.148Ω

Using the VIR calculation

V=IxR

V=40x.0148
=5.92volts

Then 5% of 230 volts is 11.5volts

Therefore 5.92 volts is within the voltdrop of 11.5 volts

i think this is correct please confirm.

I think you have to double the cable length because the voltage drops across both the line and neutral conductors.

 

[scotsparky]

no charles you dont.

VD = desighn current x mohms/m x L
1000

 

[GStueyXR]

The circuit was 80 metres long....

But they did not give you the Voltage drop figures, just the resistive load of the cable....

The answer is 13.5 volts.

 

[GStueyXR]

the last 2 part of the question told you that the circuit didnt comply with Vdrop requirements

 

[T&Earth]

Hi All fellow 2391

I also did my 2391 Thursday night, just reading these post has brought all back to me!! I found it difficuilt not realy knowing what the question was asking.

Lets hope we have all passed

Steve

 

[ezzzekiel]

the long wait is the worst, and ive just heard the guy marking is on sick leave so could take upto 6 months





just a joke before you start biting at the bit - sure you all did fine, and if not you have better understanding next time round.

 

[bobby101]

hi guys i just tried a formula calculator online regarding the voltage drop and it came out at 3.52 volts 10mm cable 40 amp load and 20 meters in length ???????
also suprised nobody picked up the fact the calculation i posted had a deliberate mistake on it honest ...... can you spot it !!!!

 

[scotsparky]

The circuit was 80 metres long....

But they did not give you the Voltage drop figures, just the resistive load of the cable....

The answer is 13.5 volts.

i read 20metres . you use the resistive load to work out the volt drop and you have to know the maximums.

230v power 5% =11.5v
230v lights 3% = 6.8v
400V power 5% =20v
400v lights 3% =12v