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Posted By Topic: Potentially stupid question

Quazi
Sep 27 2019 17:23

A customer has asked me to reliven a garden light. It is a 2m steel pole with a lantern style fitting on top. You know the type that were popular in the 70's. Anyway it is fed by good T&E TPS however the switch end has no earth cable, just P&N so there is no earth running to it.
Now, can the steel pole going into the garden be used as the earth?
   

rarrar
Sep 27 2019 18:45

change it to 12 volts and your problems go away.
   

DougP
Sep 27 2019 20:09

Good idea Rarrar.

How far can you run a constant current LED supply? They are higher voltage, but still ELV.
   

medistat
Sep 27 2019 20:39

One of these ends the problem:

https://www.mitre10.co.nz/shop/duracell-solar-path-light-h-161mm-d-180mm-stainless-steel/p/269569
   

WillJ
Sep 28 2019 08:17

Or just make it 12v and put as GLS Led 12v lamp in, easy!!
   

Quazi
Sep 29 2019 09:50

Yes 12v is a good idea. however what about using the pole as an earth? I'm interested in whether or not a steel pole would be a legitimate earth.I'm thinking it's a pole buried into the ground...?
Also could I use the 230 feed without a earth to feed doub insulated garden light. If someone hit it with a spade & just hit the phase with the spade into the soil would it blow the fuse? So many questions, so many experiments I have to carry out...

   

gregmcc
Sep 29 2019 11:46

Short answer:- NO
Long answer :- No it would not function as an earth as whole point is to keep all metal work at the same potential so than in the event of a fault the circuit protection will activate, should a fault occur in a fitting like this the fault current will return via the resistance of the soil which will be high enough to not allow for enough current to trip the protective device and the touch voltage will rise in the light and present a shock hazard.


   

Quazi
Oct 04 2019 07:43

Good answer Greg thanks for that.
   

DougP
Oct 04 2019 08:19

The thing is, that the resistance of the soil would actually be low enough to allow an RCD to operate.
However that doesn't make it any more legal. Unless it's possible to make the fitting double insulated.
   

PaleAle
Oct 07 2019 16:26

Is modifying a light fitting from its original purpose technically all good?