Plastic switch covers.

[Henthel]

Wow!
Gents thank you so much for all the input. I never thought that the thread would become so interesting. I agree with GCE that if things are not clear, all possible avenues must be investigated. In a court of law, ignorance counts for nothing. The OSH Act, Mine Health and Safety Act, Building Regulations etc. must all be taken into consideration. In the end a proper risk assessment done by a team of interested parties will find whether it is an acceptable decision or not. I think in the absence of hard and fast rules, you should let your conscience guide you as well.

[GCE]

Hi

The thread was thought provoking - I found it scary that there is no hard and fast rule that if you are using PVC wall boxes , pvc conduit , pvc switches and light fittings that you need an earth wire.It is the right thing to do but leaves it open to debate
Means that light circuit's in an installation could be wired without any earth wires.

Think there needs to be a change to the regulations and thought that maybe we need to arrange the extra wording in red below to the clause.

Not sure if anybody agrees or thinks that it is already covered.?

6.12.3.1 The following conductive parts shall be earthed:
a) all exposed conductive parts of an installation other than those described
in 6.12.3.2;
NOTE Metal enclosures on PVC conduit should be earthed if they can become
live and can be touched.
b) all conductive cable sheaths and armouring, wireways and catenary
wires;
c) the earthing terminal of a socket-outlet;
d) the secondary winding of a transformer if it is not a safety transformer;
e) earthing terminals and points ( lights switches , light fittings, etc even if PVC ) of all permanently connected electrical equipment and appliances

[Henthel]

GCE, the Regulation starts of quoting "conductive parts". It goes on to say "exposed" conductive parts. Also metal boxes on PVC that can become live and can be" touched" . Then - anything "out of arms reach" need not be earthed. These Regulations were written to protect the layman - user or tenant. Not for the electrician or competent person working on the installation. It must be safe for the person operating the switches daily. A person that is not competent should not even attempt to change a light bulb without switching off the main switch. For that matter, a careful electrician would do the same. It is very easy to become complacent and that is normally when accidents happen. To go overboard and try and earth plastic and PVC fittings would serve no purpose. Rather re-write the regulations to exclude an earth wire on light circuits where it will serve no purpose. It is like saying that you should have an earth on a double insulated appliance. If you have a short-circuit fault between live and neutral, your circuit breakers should provide protection and trip the supply before the house burns down. In most TN connected supplies, your neutral and earth are at the same potential anyway. That is just my humble opinion.

[Dave A]

I see value in amending the standard in such a way it ensures there is an earth wire available at each electrical point, except where the absence thereof is for good reason (e.g. safety supplies).

In the light switch point situation that is the focus here, we could talk about the challenge faced if there is no earth wire available and the client wants (or needs) to change the plastic light switch to something a bit fancier, (or robust) that has an exposed conductive material. The more common problem though is where the client wants to replace a light point plastic bowl fitting with a ceiling fan incorporating a luminaire.

Things change. Let's make sure there is an earth available.