Hi

This thread has made me do some serious thinking.
We need to remember that the OHSA also has a play on the regulations and the way we conduct our business .

My understanding of reasonable safe is that it must comply to section 5 , fundamentals , of the code .
So metal conduit on an old installation and now fitted with PVC switches would not need to have an earth wire as I read it .

But as pointed out by Leecatt above any replacement etc must comply to the latest version at the time.Pvc switches where not available at the time of metal conduit and it is therefore assumed that it was done much later. ( the majority of PVC switches came out after the change in reg's that stated earth wire must go to the earthing terminals of all permanently connected electrical equipment and appliances. My memory anyway)

If I look at the latest regulations I cannot come up with a reason to run an earth wire to a light switch that is PVC without an earth terminal , has pvc conduit and pvc wall box.
But - If I look at the OHSA , electrical machinery regulations , section 18 Earthing

Earthing
18. ( 1) An employer or user shall cause -
(b) all accessible metallic parts of electrical machinery that, though normally
not forming part of an electrical circuit, may become live accidentally, to be
protected by an insulating covering or to be otherwise enclosed or to be
earthed and the resistance of the earth continuity path shall not exceed
0,2 ohm, except-
(iv) metalwork of fixed electrical machinery where such metalwork is
more than 2.4 m above the floor: Provided that this exception shall
not apply where such metalwork is situated in any position likely to
become damp, or in an elevator shaft, or near rotating machinery,
or in contact with a wall, ceiling or other support constructed of or
covered with conducting material

To me , and maybe I am taking it out of context , I need to earth the metal box/ conduit as it is in contact with the wall , and to bring it into context the conduit may be above 2,4m - On an old installation I suppose that means that it must be earth but not necessarily have an earth wire.

In answer to Henthel's question "I can not see how a person can charge a customer for a complete rewire, if the earthing is within the required parameters" The introduction of SANS 10142 and the OHSA gives me a chance to insist on more than the basic requirements .I have pasted 5 pieces below which to me would be relevant when trying to persuade the client to accept my insistence on installing separate earth wires.I know that there is a chance of a hot connection which may cause a smoldering of the switch hidden behind a curtain that sets the fire off or the wiring burning back in the conduit and not tripping the supply until the roof space starts smoldering.
May sound extreme but I watched my folks lose there entire house and contents in the space of 30 minutes due to a short on an electric blanket while they were in the room.Made me rethink on what is required by regulation and what is required from me as a responsible person signing off reasonable safe.

As a responsible person signing the COC I need to be 100% sure in myself that what I am declaring as reasonable safe is definitely so .There can be no doubt within myself otherwise I will not be able to convince somebody else in the event of a problem that I did everything possible to prevent a problem.If that doubt is there I then run the risk of being prosecuted under the OHSA.

Think it a reason that I don't do COC type work on existing installations as we just quote on the work , to do it as we see correctly , only to go back later to see the disaster. If we do COC type inspections we will only do for the buyer as he understands whereas the seller wants as cheap as possible.


Extracts from SANS 10142-1
Compliance with this document cannot confer immunity from legal
obligations

The aim of this part of SANS 10142 is to ensure that people, animals and
property are protected from hazards that can arise from the operation of an
electrical installation under both normal and fault conditions. An electrical
installation has to provide protection against:
– shock current,
– overcurrent,
– fault current,
– overvoltage,
– undervoltage,
– excessive temperatures, and
– electric arcs.

This part of SANS 10142 is concerned with ensuring the basic safety of
electrical installations. To ensure the protection of people, animals and
property and the proper functioning of an installation, the designer of an
electrical installation should be aware of:
a) the characteristics of the power supply,
b) the nature of the demand, and
c) the operating environment of each part of the installation


Extract From General Administrative regulations
9. General duties of employers and self-employed persons to persons other than their employees

(1) Every employer shall conduct his undertaking in such a manner as to ensure, as far as is reasonably practicable, that persons other than those in his employment who may be directly affected by his activities are not thereby exposed to hazards to their health or safety.

(2) Every self-employed person shall conduct his undertaking in such a manner as to ensure, as far as is reasonably practicable, that he and other persons who may be directly affected by his activities are not thereby exposed to hazards to their health or safety.

Extract from General Safety Regulations
2. (1) Subject to the provisions of paragraphs (f), (g), (h) and (i) of regulation 5 of the General Administrative Regulations published under Government Notice R. 2206 of 5 October 1984, every employer and every user of machinery shall make an evaluation of the risk attached to any condition or situation which may arise from the activities of such employer or user, as the case may be, and to which persons at a workplace or in the course of their employment or in connection with the use of machinery are exposed, and he shall take such steps as may under the circumstances be necessary to make such condition or situation safe