Steel wire armour

[Mike Irving]

Hi.....I think I'm being dumb.....when installing 35mm swa cable and then recording it on the schedule of test results sheet ....what conductor size do I log for live and cpc.....thanks in advance...

 

[jackhammerJIM]

35 mm for live . What have you used as the cpc ?

 

[Mike Irving]

I've used the swa Earth to the DB and then attached a 2.5mm lead to the cpc board...

 

[jackhammerJIM]

i would record swa in the cpc box .

Have you calculated the 2.5 fly lead will be sufficient ?

 

[SJD]

I've used the swa Earth to the DB and then attached a 2.5mm lead to the cpc board...

If the only earth for whatever is being supplied is via this 2.5mm lead, then I doubt it is going to be sufficient.

 

[jackhammerJIM]

If the only earth for whatever is being supplied is via this 2.5mm lead, then I doubt it is going to be sufficient.

It could be a very long cable run fused down to 20 amps . but i am also doubtful :dizzy2:

 

[SJD]

It could be a very long cable run fused down to 20 amps . but i am also doubtful :dizzy2:

Indeed, or even an extremely long lighting circuit on a 6A MCB, ... more information is needed.

 

[davesparks]

Hi.....I think I'm being dumb.....when installing 35mm swa cable and then recording it on the schedule of test results sheet ....what conductor size do I log for live and cpc.....thanks in advance...

Using a little bit of common sense would suggest that recording the size of the conductor in the boxes where the size of the conductor is required would be a good idea!
It is common practice to record something like 'swa' in the box for the cpc for such an installation, but you can equally record the actual csa (which you will know from when you looked it up to do the calculation for it) although it will look a bit odd as it won't be a standard size.

Applying a little more common sense you could also see that the flux lead to the banjo would be better off being of an equivalent size to the rest of the cpc (allowing for the difference in materials of course)

 

[westward10]

I generally record SWA, but if you want a size and assuming it is a four core the csa of the armour is approximately 80.0mm. Due to the higher resistance of steel in relation to copper this relates approximately to a csa of 6.0 for use as a cpc. Hence the size of conductor from your earth tag should not be less than 6.0.