Earthing metallic armour of SWA cable.

[Goody]

I have connected the metallic armour of a 1 .5mm SWA cable (about 50ft run) to the met on the main CU using a 10mm earth cable. Is this a bit of an overkill or should I use 6mm earth cable instead?

What calculation applies to determine the cross section of the earth cable in this case?

Cheers!

 

[Engineer54]

Do you mean via flying lead off a banjo connection?? If so, i wouldn't bother replacing what's already installed, but yes it's a bit of an over kill as you put it...lol!! To determine the CPC size required use the adiabatic equation....

 

[pushrod]

I have connected the metallic armour of a 1 .5mm SWA cable (about 50ft run) to the met on the main CU using a 10mm earth cable. Is this a bit of an overkill or should I use 6mm earth cable instead?

What calculation applies to determine the cross section of the earth cable in this case?

Cheers!

If it is a copper 1.5mm² line then you need no more than a copper 1.5mm² cpc

However 543.1.1 takes over and if it is not part of a cable then min size is 2.5mm² if protected; and 4mm² if not protected. So yes a bit of overkill with the 10mm²

 

[Goody]

If it is a copper 1.5mm² line then you need no more than a copper 1.5mm² cpc

However 543.1.1 takes over and if it is not part of a cable then min size is 2.5mm² if protected; and 4mm² if not protected. So yes a bit of overkill with the 10mm²

Thanks for the input, pushrod.

 

[telectrix]

it ain't overkill if 10mm is all he had to hand. making a special trip to wholesalers for a bit of 4mm or 6mm would be silly.