Trainee questions to answer

[telectrix]

first use ohm's law to get R. i.e R=V/I = 2.69/36 = 0.075 ohms.

then use R = pL/A, where p = 1.7 x 10 -8

 

[Chrisuk]

first use ohm's law to get R. i.e R=V/I = 2.69/36 = 0.075 ohms.

then use VD = mV/A/m x L x A, where you know V,Aand L, so... mV/A/m = V/(L x A ) = 2.69/ (42 x 36) = 1.779. from tables in BS7671, find the csa of the cable with that value. i.e 25mm ( as close as)

Really do appreciate you explaining that one for me

 

[telectrix]

you should use the calc. R = pL/A, where p= 1.7 x 10 -8, L =length and A = csa.

 

[Chrisuk]

first use ohm's law to get R. i.e R=V/I = 2.69/36 = 0.075 ohms.

then use VD = mV/A/m x L x A, where you know V,Aand L, so... mV/A/m = V/(L x A ) = 2.69/ (42 x 36) = 1.779. from tables in BS7671, find the csa of the cable with that value. i.e 25mm ( as close as)

Previously the answer of 10mm was given the reply of spot on which would have to be 1.0-1.5mm

Is it like mcb's that for example the table shows 1.5 and the. 2.5 and the answer being 1.7 so would be use the 2.5mm section, always go bigger but never smaller??

 

[Chrisuk]

actually, you should use the calc. R = pL/A, where p= 1.7 x 10 -8

Oooh damn, that's easy doing that, answer 9.8mm

 

[telectrix]

deleted.

 

[pennychew]

Can you explain how to work this one out because the help screen shot u put up only shows how's to work out festivity which I know how to do
If u had given the resistivity maybe I could of found the area but so far we have been told how to work out resistivity PlxL/A so I'd appreciate the working out on that one

Hi mate, I'm on nightshift so I've never had a chance to get back to you on this but it looks like you've got it sussed!

We've been doing some of these exercises from a book called 'basic electrical calculations' by Chris kitcher and it's been a big help for me, I'd recommend it if you like doing the calcs for stuff.

 

[Chrisuk]

I've got electrical basic installation by T Lindsey which we use in class, I'll have to look for the calculations book

 

[pennychew]

I've got electrical basic installation by T Lindsey which we use in class, I'll have to look for the calculations book

I've got that one as well but we've hardly used it so far to be honest!
I'll PM you about that other book

 

[Chrisuk]

Really, we use it each day with have the classroom day, that and learning lounge, we have our health and safety exam beginning of jan when we go back, so far we have done unit 201 and a lot of 202!!!

 

[pennychew]

Really, we use it each day with have the classroom day, that and learning lounge, we have out health and safety exam beginning of jan when we go back, so far we have done unit 201 and a lot of 202!!!

Yeah we've got the H&S exam back end of January, I'll be glad to see the back of it!

 

[matt1386]

How are you lads finding the 202 ?

We aren't doing our h&s and 202 exam until around May, everyone else I speak to are doing it beginning of the year !

We haven't even started studying the 201 h&s yet

Matt

 

[pennychew]

How are you lads finding the 202 ?

We aren't doing our h&s and 202 exam until around May, everyone else I speak to are doing it beginning of the year !

We haven't even started studying the 201 h&s yet

Matt

Hi Matt, really enjoying the 202, I love all the science and the formulas for how stuff works as im a proper geek with owt like that! we have the online exam for that on the 16th of June. How are you finding it?

I have our scheme of works for the 202 which is broken down into what we intend to cover each week, I'll post it up when I get on my computer as I can't work out how to do it on an iPad!

Stu

 

[Chrisuk]

How are you lads finding the 202 ?

We aren't doing our h&s and 202 exam until around May, everyone else I speak to are doing it beginning of the year !

We haven't even started studying the 201 h&s yet

Matt

I would of thought colleges would teach in a very similar way, if most are doing 201 exam in Jan like i am i would of thought you would, its not difficult anyway, we did the latest mock my tutor could get hold of and even a couple of lads that started end of Nov so had been with us for about 3 weeks passed the mock!

202 is good, im enjoying it at the moment, just make sure you remember all the formulas!

matt what are you upto in the workshop, i missed 2 lessons because i had a funeral in france to go to but im upto

PVC Singles - 2 way intermediate lighting
as a single switched light and 2 way switched light

should not be a problem since ive just done 2 sockets so i have most the conduit already, ill just need 1.5mm2 instead of 2.5mm2 i used for my rfc

i REALLY wish i could do more than the 1 day each week in the workshop, i could stay for hourssss doing it!!

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Hi Matt, really enjoying the 202, I love all the science and the formulas for how stuff works as im a proper geek with owt like that! we have the online exam for that on the 16th of June. How are you finding it?

I have our scheme of works for the 202 which is broken down into what we intend to cover each week, I'll post it up when I get on my computer as I can't work out how to do it on an iPad!

Stu

Id like to see that Stu

 

[pennychew]

Not sure if this will work as its a word doc...

If it does this is the scheme of works for our 202 unit

View attachment SoW 2365 L2 Yr1 unit 202 13-14-1.doc