Phil B wrote:

a nice article on testing thanks. A few points:

1. Since wiki is available world-wide should you say that you are referring
to UK standards?

I had taken that as kind of implicit since it does start off "Welcome to
the uk.d-i-y wiki!", but having said, that there is no harm in spelling
it out.

2. Are you specifically targetting testing of sockets? If lighting
circuits are involved then there are other issues like switches being on for
testing (all combinations for 2 way switching), bulbs out.

Power circuits were the main focus of the article, but lighting could
certainly be added. (might be worth restricting it to power circuits at
the moment)

3. Views on other tools? Neon testers (love or hate them?) Electronic
induction things (ditto)?

I agree that stuff should be in the wiki someplace, not sure this
particular article needs cluttering with that info though.

4. Suggest you add that conductors should be checked before you touch them
(Faulty switch? Wrong switch? Is it up or down for off?).

I have tried to spell out that the circuit needs to be off at the CU
main switch before getting into any testing.

That you should ensure that others cannot alter switches.

Yes that is worth adding.

That all circuits are isolated before you disconnect any wiring - even
neutrals (in case of cross connected circuits).

5. Is there a mismatch between the sort of meter you indicate and the sub
ohm values which you refer to in your tables on continuity testing? To

Yes there is. The details on resistance checks grew a little beyond the
scope of the basic continuity type tests that I was anticipating at the
start of writing it. Hence the meter I liked to is not appropriate for
some of the tests. (I specifically linked to an analogue type meter to
avoid getting sucked into any problems with false positives you can get
with voltage indications on very high impedance DMMs etc - however those
issues have not really become relevant in the article as it stands)

be honest you're probably only looking for an indicated value the same as
shorted leads or for no needle movement at all and I can't think of many
circumstances where that will not be adequate though it will be an issue if
you are completing test reports. Maybe you need to acknowledge that such
testing is on the limits of inexpensive meters?

I still want to try and keep it at a "useful to the end user" level
rather than let it get too technical, but I think a bit more guidance on
test gear is worth including. Also links to a reasonable DMM might be
appropriate as well as a couple of pointers to real test gear.

In reality the resistance info for anything much beyond 2.5mm^2 circuits
is not that relevant for most circumstances. However a reasonable DMM
will usually give you enough resolution (down to the tenth of an ohm) to
make reasonable use of the tables in more than a go/nogo way.

6. How do you test RCD? Is the test button adequate? A plug with a big
fat resistance of 8K ohm between L and E? Mega expensive test meters which
time the disconnect?

Slightly outside the scope of this article, although I have in mind a
big article on RCD issues in general that would include testing, and
tracking down sources of trips etc since that seems to be a frequent
topic of discussion here.

7. How can you test that the earth to the house is okay? Continuity
between N and E?

The tests using a socket tester would probably highlight a gross failure
of the external earth. However I feel that is getting a bit outside the
scope again. (I want to try and avoid having one article growing and
expanding into a universal document on electrical installations and
becoming so dense that it is impossible to get basic information out of.
I would rather have lots of smaller articles that focus on particular
topics where this is possible).

8. A short glossary? CPC? RCD? MCB? T&E?

Yup certainly, that is already noted in the discussion page as needed.



Thanks for that Phil, good points which I will try and incorporate.

--
Cheers,

John.

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