Hello i am new to forums regarding test and inspect

[Jaykay]

hello, new to forums,

I am looking to get into the 2395/6 test and inspect and i am wondering what the kind of maths are needed for electrical theory any books that cover that stuff

want to get all the maths (hard stuff) understood before booking the course
vectors? as in power correction are they in ?

 

[telectrix]

take it you mean 2394/5. 2396 is design course. i recomment chris kitchers book, testing and inspection of electrical installations.

 

[Rpa07]

Welcome to the forum JayKay, if you could fill in the profile a bit more so people know where you are in this career it'll help with responses. Cheers

 

[Specialist]

You could try the JTL Electrical Installation books & the Newnes Electrical pocketbook.

 

[MODECSOFT]

Welcome

 

[Ian1981]

There's always a question on insulation resistance and calculating the overall resistance from a number of given values.
1/RT= 1/R1+ 1/R2+ 1/R3 + 1/R4+ 1/R5
Finding the common value to divide the values into.
Enjoy

 

[Rpa07]

Wrong thread methinks, been done before and won't be the last time!

There's always a question on insulation resistance and calculating the overall resistance from a number of given values.
1/RT= 1/R1+ 1/R2+ 1/R3 + 1/R4+ 1/R5
Finding the common value to divide the values into.
Enjoy

 

[Ian1981]

Wrong thread methinks, been done before and won't be the last time!

It's a typical maths question that you will get on the 2395 theory exam.

Only worth around 3-5 marks tho.

Guidance note 3 would be the obvious choice tho for a book to understand as there are basic calculations and examples near the back.

 

[Rpa07]

Still the wrong thread - that is the thread about the maths questions not the inspection and test.

It's a typical maths question that you will get on the 2395 theory exam.

Only worth around 3-5 marks tho.

Guidance note 3 would be the obvious choice tho for a book to understand as there are basic calculations and examples near the back.

 

[Rpa07]

No i'm wrong - sorry!

 

[Ian1981]

No i'm wrong - sorry!

Haha don't worry about it.

 

[ruston]

That , or a very similar question was in the 2391 I took.

 

[Ian1981]

That , or a very similar question was in the 2391 I took.

It was in mine and on example papers given to revise to.
If you don't know it it's not worth panicking over as it's worth about 3 marks I think.
Only other maths stuff I can think is your ring final calcs i.e. 4.0 mm with 1.5 ,cpc is 2.67 times the difference you should expect on end to end continuity compared to line and neutral. , 2.5 1.5 cpc 1.67 etc.

 

[ruston]

The rule of thumb calc was asked to be applied for in max values too.

 

[Ian1981]

The rule of thumb calc was asked to be applied for in max values too.

That's right and possibly may need to adjust ambient temperature when testing say another 10 degrees and state the max zs allowed when testing at the site temperature

 

[The Ghost]

Well when I did the 2395 I was armed to the teeth with the maths doing product over sum calculation for the RT above. However on the day I was zeugswanged and was asked to describe all the terminals on earth rod test, which I had not looked at too hard. And then you get a scenario of something like a factory and circuits described and a set of questions of various sorts on that. Things like what tests cannot be performed as the client does not want the sockets dis-connected, and it is not the first thing you would think of. The thing is all in the terminology. And strangely I had very little technical maths. Just simple things like resistors in parralell and series but only a couple not like the several above. I recommend Andrew Butlers - Basic Electrical Formulae for the maths. It's a little gem for revision. Bear in mind the Cmin factor has since been introduced with his worked examples.

 

[ruston]

The exam I referred to was the 2391 taken 2004.

 

[balodis]

A book I would recommend you check out would be the City & Guilds 'Exam Success Inspection and Testing 2394 and 2395' some good guidance in there.