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Bad 'Mains test plugs' ?

Hi All,

Those 13A fitting 'Mains test plugs' .. are there good one and bad ones (generally) or are they all basically as 'good' (bad?) as each other?

Eg, you can get one on Maplin for £3.99 yet I'm sure I've seen them in my local electrical shop for £16+?

I would have though 3 neons and a few resistors in a plastic moulding should be nearer the £3.99 mark but have I missed something (like certification / accuracy / reliability etc)?

I have had a blue one for many years now (or *had* till I went for it the other day and can't find it ..) so was thinking of getting a replacement till it turns up (and it will of course) but didn't know if there were subtly different / more sophisticated jobbies out there now that warranted the high cost (and if so were they 'better' >

safer)?

All the best ..

T i m

p.s. Any of the mains sheds sellum (at the right price) please?

Reply to
T i m
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I've got a 4 quid one and it is fine. Obviously, it isn't proper test equipment, but it is excellent for a rapid check. I got it either from Screwfix or TLC.

Christian.

Reply to
Christian McArdle

Cheers fella.

I believe my 'errant' tester was (is) a

"Martindale classic CP501 Check Plug"

This it suggests shows a 'good' condition by having all 3 neons on, so if a neon fails it doesn't suggest everything is ok (unlike the more basic testers than don't indicate 'positive' for no voltage between earth / neutral)?

That said, neons are pretty reliable aren't they .. ?

All the best ..

T i m

Reply to
T i m

No. A neon is a neon.

They're great for finding faults in circuits that are perfectly connected and in good condition, but might have topological faults (swapped connections, no connection). For anything in-between (leakage, high impedance) then they're beyond useless and possibly dangerous, if trusted as a safety measure.

If swapped wires are a risk (?!) then they could be useful. For anything else, then I'm just not sure what you'd expect them to tell you.

Reply to
dingbat

My cheapie is also like this. 3 lights means go.

Christian.

Reply to
Christian McArdle

Ah, ok, thanks ;-)

Cheers ..

T i m

Reply to
T i m

So none of these devices use further electronics / LED's for example?

Understood (although I believe there are some 'sophisticated' variants on the basic 3 neon jobbies that can also display earth loop impedance etc).

Some 'swapped wires' can be a risk can't they (live / earth) or have I missed summat (again) ;-(

Well nothing, I was just asking if 'you get's what you pays for' with these things and it would seem from the other replies for yer basic 3 neon jobbies the answer is no (unless you only pay a fiver that is) ;-)

The background thought (and reason for the question) was have things moved on with such devices .. saves all the 'who sold you that then' type comments .. ;-(

All the best ..

T i m

Reply to
T i m

Mine, at around =A315, also tests RCDs which I've found handy. I say 'test' but whilst it can apply various fault currents (10mA, 30mA,

100mA etc) it doesn't actually test the trip *time*. That said, it's been useful if only as a reassurance tool - arguably the intended purpose for this kind of tool.

It was from CPC however looking at the catalogue I don't know if it's still available as they have a similar one at

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but it's =A320 however it does appear to test RCD trip time (albeit only for

30mA?).

Mathew

Reply to
Mathew Newton

As well as the basic 3 neon ones that check for swapped wires, I've seen more expensive ones that claim to test a bunch of extra stuff, and iirc have a 3rd indicator mode (as well as on/off). But I dont recall exactly what they claimed and havent used them. The basic ones can be assembled for =A31 or bought for a few earth pounds.

NT

Reply to
meow2222

It's a very useful quick check tool, e.g. are the wires the correct way round or has someone colourblind been allowed in here (happened to me bigtime, in a marine environment), and is there some sort of earth present? (not necessarily a very good one). Very good for quick-checking extension leads.

I remember one of the electronics mags with a self-build project using resistors and leds.

I think I may have seen (or possibly imagined) an lcd version somewhere that popped up a little "good" message or told you the fault - just in case you couldn't compare the light pattern with the list on the front.

Reply to
dom

My one uses three multicolour LEDs which light in various combinations and colours to indicate different fault conditions.

Not seen one that does earth loop, but there are various electronic ones that can detect more faults than the basic ones.

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?SKU=IN02208>>If swapped wires are a risk (?!) then they could be useful.

ITHM "if swapped wires are likely" (they always present a risk if present). Also one of the standard tests on new wiring ought to test polarity at each outlet.

Some have audio go/nogo indications - handy for brightly lit environments. Others have more sophisticated fault reporting.

Reply to
John Rumm

The message from T i m contains these words:

IIRC they can't tell the difference between a correctly wired socket and one with neutral and earth interchanged. But I could be wrong.

Reply to
Guy King

The basic ones are just neons and give an indication of wrong connection. But more sophisticated ones exist which do other tests.

Reply to
Dave Plowman (News)

You are correct. Mine came with a specific warning about this. It is quite an uncommon fault, though, at least after the consumer unit.

Christian.

Reply to
Christian McArdle

This unit is handy for testing when doing quotes; as a quick test on the condition of the earth loop: -

Martindale E-Ze Check Extra

It gives an earth loop test of 10, 100, 200 or 500 ohm, useful when you are assessing the need for an update on the main bonding.

Jaymack

Reply to
John McLean

I thought there must (and found via Google) be some cleverer ones out there now.

Just didn't want to spend more money than needed on summat that was basically something I could make myself, but needed to know if there was something 'sexy' that could be bought for a few quid more (from the guys that were using this stuff regularly). ;-)

All the best ..

T i m

Reply to
T i m

Well exactly. Not only to you learn that there are no major issues with the wiring but that the RCD does do *something* ;-)

Hmm, interesting. Isn't it annoying how often these days a handy VFM product disappears to be *nearly* replaced by an 'alternative' ? ;-(

All the best and thanks for the heads up Mathew ..

T i m

Reply to
T i m

Kool .. we like multicolored flashing lights ;-)

Understood.

Something you might not consider till you are having to shade the thing with yer hand to see what's going on! ;-(

So it seems .. I suppose it really depends on if they actually do the job better or offer more options etc ?

All the best John ..

T i m

Reply to
T i m

And something else I did today .. and quickly highlighted a blown fuse ;-)

My Google search actually threw up a DIY neon jobby .. trouble is it cost the same to make as it would to buy (as is often the case these days) ;-(

Oh dear ... sounds 'tekky' though .. I want one! ;-)

All the best ..

T i m

Reply to
T i m

I think you are right Guy .. the one I picked up today specifically states "This unit will not detect the reverse of earth and neutral" ;-)

However I don't think that fault is particularly dangerous and would be indicated by the RCD tripping (if there is one) in any case once the faultily wired socket was used?

All the best ..

T i m

Reply to
T i m

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