Cable calcs for right size cable

[shocksl]

Hey guys as some of you may know that I'm studying electrical installation at York college. I haven't really worked on site yet.

Just wanted abit of help. As I'm doing cable calcs etc which I've got the hang off.

Only issue I have is suggesting improvements as to smaller cable etc. Plus I don't know what the cable size means as in if they are too big for a domestic property or whetever we doing the calculations for.

Is there anywhere I can make myself familiar with cable sizes. So I can say this cable is too big etc especially based on ref method etc.

Otherwise I won't know. Just need to understand what the standard sizes should be .

Thanks for any help

 

[westward10]

Your cable calculations will give you a suitable cable size making it smaller is likely to mean it won't comply.

 

[shocksl]

You are right but part of the call we have to determine if its correct or not .. so we have to change some of the factors ie group cg etc

So it's important for me to know what a re considered standard sizes or not.

 

[westward10]

So are they saying once a size is calculated this maybe considered oversized for installation purposes for example, calculations give you a size of 10.0mm² for a domestic lighting circuit. You then have to change it's installation method to reduce it?

 

[shocksl]

So are they saying once a size is calculated this maybe considered oversized for installation purposes for example, calculations give you a size of 10.0mm² for a domestic lighting circuit. You then have to change it's installation method to reduce it?

That is correct.

 

[DefyG]

Standard sizes are 1, 1.5, 2.5, 4.0, 6.0, 10.0. 16.0, 25.0, 35.0 sq mm upwards!

Is it because your calcs are coming up with figures like 8.6sqmm for example?

 

[shocksl]

Standard sizes are 1, 1.5, 2.5, 4.0, 6.0, 10.0. 16.0, 25.0, 35.0 sq mm upwards!

Is it because your calcs are coming up with figures like 8.6sqmm for example?

For the exams it's a deliberate thing. So we then have to change factors like grouping etc and seperate them in order to make the size smaller for installation purposes.

 

[westward10]

If you are comfortable with cable calculations then look at how you can change the increased cable size. Reduce the grouping, is there thermal insulation, change the cable type.

 

[shocksl]

If you are comfortable with cable calculations then look at how you can change the increased cable size. Reduce the grouping, is there thermal insulation, change the cable type.

Yes I'm pretty comfortable doing all that. This is why I'm trying to get grasp what are standard sizes or types of cables used. Maybe there's a website. But someone above just posted some .