On 01/05/2019 08:38, wrote:
P.S....

The metal shed and metal framed greenhouse are both on a patio which
in turn is sat on sharp sand followed by 100 mm mot1 hardcore.

The nearest bit of earth to hammer an earth rod into is the lawn and
this rod would be at risk of lawnmower or strimmer damage.

Then dig a small pit and put in a protective enclosure for the rod and
connection to it.

Only alternative is to drill right through patio, sharp sand and
hardcore and use an extra long earth rod...

Yup, that would probably be easy enough - in fact you can probably just
hammer drive it through the sand and MoT.

I would be inclined to start with a normal 4' rod, and then test that
once installed before deciding if you need to couple another rod to it.

http://wiki.diyfaq.org.uk/index.php/...ode_resistance

I was going to use 20mm plastic conduit on all the cable runs between
sub consumer unit and all the electrical accessories to improve both
mechanical protection and implement "double insulation" between the
conductors and the metal structures.

Plastic gives some mechanical protection and can make a surface wired
job look neater. Trunking is a bit easier to install.

This is addition to using IP66 sockets and switches along with IP66
fluorescent lighting battens in both structures.

Pick whatever is appropriate for the location. Inside a shed you would
be ok with a lower IP rating normally so long as it doesn't leak.

--
Cheers,

John.

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