17th Edition Exam Question

[uksel]

Hi folks,

Just doing some online sample papers for the 17th Edition (2381) Exam, came across this question, I know the answer but I just couldn't find confirmation in the red book. could anybody point me in the right direction please?

Also, any good resources for the 17th update exam would be greatly appreciated, as I think I may be barking up the wrong tree a bit practising for the full

anyways, Question;

Within a paper mill having a conduit wiring system, insulation fault protection must be provided using an RCD having a residual operating current not exceeding

1. ? 30 mA
2. 300 mA
3. ? 500 mA
4. ? 750 mA

 

[acat]

I think with that one the hint is in the fact that its a paper mill so a fire hazard in which case I would think you are looking at 422.3.9 page 68. have a look at the exam simulator at ElectaCourse Home Study and Distance Learning Courses and Revision and Exam Aids it may help you.


Chris

 

[uksel]

yeah, I think you've nailed that one. thanks very much for that!

I knew there was something of relevance to the fact they mentioned it being specifically a paper mill, but I was thinking more how it would fall into a section 7 special location rather than the fire hazard.

i'll check that link out now

cheers chris

 

[acat]

Its a pleasure mate


Chris

 

[uksel]

I have another i'm having a bit of trouble sourcing the answer

Where a circuit forms part of a TN system, the maximum permissible earth fault loop impedance (Z,) for a 30 A socket outlet circuit used for portable equipment and protected by a 13S 1361 fuse is

1. ? 1.0 Ω
2. 1.2 Ω
3. X 1.5 Ω
4. ? 2.0 Ω

completely lost...

 

[steviesparks]

Table 41.1= max disconnection time TN.....0.4 seconds @ 230v

Table 41.2= 1361 @ 15A......3.28 ohms

use the nearest to 13A which is 15A

simples

 

[uksel]

the answer given is 1.2ohms. and 30A socket outlet ??? which is why i'm having trouble

 

[acat]

I think your answers given are wrong IMO if you look at page 48 table 41.2 fuses to Bs1361 rated at 30A the answer is 1.15 ohms, check that with your tutor my old grey matter is turning whiter by the second.


Chris

 

[Notsosmart]

I think your answers given are wrong IMO if you look at page 48 table 41.2 fuses to Bs1361 rated at 30A the answer is 1.15 ohms, check that with your tutor my old grey matter is turning whiter by the second.

Chris

Totally agree Chris; the old exam Typo strikes again. 1.15 Ohms according to the BRB

 

[uksel]

you know, for some reason i never considered it being a typo

thanks again folks, your time and effort is much appreciated


nb. watch this space for any more revision dilemmas

 

[acat]

Im all excited waiting for the next question did you find out what the actual pass mark is these days thanks



Chris