Earthing SWA cable?

[Roger Moss]

I am running a 16mm2 SWA cable down my garden to run a (single phase) heat pump. I see that SWA cable is available in both 2-core and 3-core forms. Do I need a 3 core cable so I have an earth conductor or is it more sensible to earth the heat pump via a local ground rod? Or both?

Thanks Roger

[David Hansen]

On Wed, 20 Feb 2008 20:53:32 +0000 someone who may be Roger Moss wrote this:-

2 core cable has an earth conductor, the armour. Take a look at the electrical supply to many buildings and you will see that the armour is used as the earth. If it's good enough to be used to provide an earth connection to a house it should be good enough to do the same around a house, provided it is installed properly.

A lot more information is needed. As a start using a search engine on this group will reveal plenty of information on sheds. The principles are much the same for a piece of equipment which will presumably be mounted in some sort of enclosure.

[John Rumm]

No you only need two core - you can use the armour as an earth conductor should you choose to opt for that solution:

more sensible to earth the heat pump via a local ground rod? Or both? This is a somewhat deep subject, you may find this handy for a discussion of some of the issues:

particular: