hello could anyboby tell me if this is safe , i have wired up lights to shed as follows two 400watt lights at either side ,the live wire from the fuse box going to a waterproof lightswitch coming out of the lightswitch both live feeds to the lights the neutral from both lights going to the fuse box and the earth from one light via the lightswitch to the fuse box  the other straight to the fuse box is this ok or will i get zapped ??

they are internal big shed 70 foot long i have earthed the light switch as it has a point to place an earth wire  the switch is plastic so maybe it does not need one? to isolate the lights would the neutral come out the lightswitch connected to the live out wires to the lights ?

[quote author=HandyMac  link=1098995370/0#1 date=1098996533]I don't personally like the sound of the earth being routed via the switch. The more junctions you've got in a cable the more potential points of failure you have., and you do not want an iffy earth connection. You've taken the neutrals straight back to the fusebox so why not take the earths back as well? [/quote]

There could be nothing wrong with that arrangment, however doesnt sound normal admitedly, unless its single core cables or somthing.

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Why?

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All earths must go back to the Consumer Unit/Fuse board to properly earth all the fittings, anything plastic wont need earthing, however any earths must all be connected together with terminal block or similar to ensure continuity of the earth.

To properly isolate the neutral and the live, you would need an isolator or double pole switch, fuses or circuit breakers should only be placed on the live conductor, hoever they shouldny be any need for this.

An RCD unit wouldnt go a miss on protecting all the socket outlets, and anything outside in damp conditions or similar onerous conditions.

Finnaly, do you know what sort of supply earthing arrangments you have, e.g. is the earth supplied by your incoming cable, are you on a farm or in a country location and have a earth spike or rod, which is a long copper rod or similar placed deep in the ground which supplies a source of earth?

Your arrangment sounds fine, but always remember the Neutural should never be switched or fused, except at the fuseboard or consumer unit, how you have it is OK.

Its good practice to take an earth to all accessories, including plastic switches, as you have done.
When LS said "but always remember the Neutural should never be switched or fused" he meant independantly of live, ie: switching neutral, not live.  Switching both in a double-pole switch is fine, even preferable.

Yep, it's a good suggestion, however alot of weatherproof fittings are still single pole, altho you can get double pole if you wish.

This is still only 3.5 amps.  Most switches are rated at 5 amps or above if I'm not mistaken?

Yep, as SS said, 5A or above, dimmers are a totaly different ball game.

6A = 1380Watts

Yes thats fine.