Test equipment?

[xr4x4]

Hello all,

Being sorting a problem with some external decking lights over the last 2 days.

The lights where tripping the rcd when switched on, turned out to be a little water in a waterproof junction box, problem solved.

Trouble is, I had to find the fault the hard way and my standard multimeter couldn't find any fault on the circuit. (which i wasn't suprised about)

Now I'm thinking of investing in a meter of some kind, but have no idea on what to get, an insulation tester at a guess.

What do you guys recommend that's not too expensive that will do the job?

Thanks.

 

[EFLImpudence]

Yes, you would need an Insulation Resistance tester to show if the circuit is alright.

They include a Continuity test as well to help you find a fault.

I don't know how much you want to spend but having a look through ebay will give you an idea. Any reputable make should be ok

http://shop.ebay.co.uk/i.html?_trkp...tion tester&_trksid=p3286.c0.m14.l1513&_pgn=1

That is a Multi-function tester page but enter IR when you get there.

 

[xr4x4]

Thanks, was hoping not to spend that much, as I would hardly use it.

I was searching for 'Insulation tester' on eBay, are they the same thing?

 

[EFLImpudence]

Try this page

http://shop.ebay.co.uk/i.html?_nkw=insulation+tester&_frs=1&_trksid=p3286.c0.m359

 

[PrenticeBoyofDerry]

Something like this will do just about all you will need.
Robin MFT

 

[xr4x4]

Thanks again, that's what I was looking at but will they do what I want them to do, i.e would they have found a fault like water over L+N+E?

How do they work? Do they work by putting a voltage down one cable and then measures resistance on the other phase/wire?

Just guessing?!

 

[xr4x4]

Something like this will do just about all you will need.
Robin MFT

Thanks for that, I've put it on my watch list!

 

[PrenticeBoyofDerry]

If you have the cables in water and this is causing a dead short.
It can be picked up two ways, using the continuity test but with open ends or the IR test which will send a DC voltage down the conductors you are testing.
This will pick up a short across the cables. In your case.

 

[EFLImpudence]

will they do what I want them to do, i.e would they have found a fault like water over L+N+E?

Yes, you have to measure between two wires at a time (L-N,L-E,N-E). The minimum allowed on 230V is 2MΩ but this is really low - a new cable will be >1000MΩ if the meter measures that high.
Cannot have any load on the circuit.

It will only show you on which circuit the fault is - they're not magic.

A fault like yours would have measured 0.00MΩ then you use the continuity (but this would not show a 'damp' fault)

How do they work? Do they work by putting a voltage down one cable and then measures resistance on the other phase/wire?

Yes, 500V for testing 230V circuits - but a meter which has a 250V setting as well is useful for first test - to show if you have forgotten to unplug something without damaging it.

 

[Taylortwocities]

Per the above. Be very careful with an IR tester. They have the capability to poke up to 1000v DC up the circuit being tested. If you do this across live and neutral you will kill most things if they are still connected. Most susceptible are dimmers, transformers. Fluo lights , etc etc.
Also, there are safety precautions to take before wackinh high voltages up circuits.
IMO there is no point spending money on expensive test equipment unless you know what to expect and how to interpret the readings.

 

[EFLImpudence]

Per the above. Be very careful with an IR tester. They have the capability to poke up to 1000v DC up the circuit being tested. If you do this across live and neutral you will kill most things if they are still connected. Most susceptible are dimmers, transformers. Fluo lights , etc etc.

Yes, and RCBOs

 

[ban-all-sheds]

The lights where tripping the rcd when switched on, turned out to be a little water in a waterproof junction box, problem solved.

Trouble is, I had to find the fault the hard way and my standard multimeter couldn't find any fault on the circuit. (which i wasn't suprised about).

The RCD was tripping because you had a fault to earth.

An IR tester would have told you whether it was a L-E or a N-E or both fault.

But it wouldn't have told you much that you didn't already know and it wouldn't have told you where the fault was.

Anyway - time to trot out my usual recommendation. Look on eBay for Beha, Unitest or Telaris (all the same thing). Little known German brand (now owned by Fluke), which because it is little known often go for very low prices - I've seen all-in-ones go for way under £100.

And take no notice of "16th Edition" vs "17th Edition" - there were no changes to testing requirements, but sadly you've missed the boat re all the dipstick electricians who flogged off what they "thought" was obsolete kit because they "thought" they needed new.

 

[EFLImpudence]

all the dipstick electricians who flogged off what they "thought" was obsolete kit because they "thought" they needed new.

Wikipedia - never knowingly wrong:
Thought is a mental process which allows beings to be conscious, make decisions, imagine and, in general, operate on symbols in a rational or irrational manner.

I couldn't resist it.