On 17/12/2012 17:54, Caecilius wrote:
On Sun, 16 Dec 2012 21:52:38 +0000, Fredxx wrote:

You can buy affordable clamp meters where if you can pass just the live
and neutral through the clamp together you can measure residual current
directly. Depending on supplementary bonding you can also get an
indication by measuring the current flowing in the protective conductor.
You might then be able to find the offending circuit.

That's interesting. I thought that sensitive clamp meters were fairly
expensive.

They are, but... I bought a Fluke 360 a couple of years ago and
wouldn't be without it now.

And to answer your original question:
(e.g.) http://adastrahire.co.uk/search?q=rcd+tester

Or ring round your local electrical wholesalers, many of them do test
equipment hire. What you really need is a leakage data logger though...

--
Andy