RCD adaptor won't reset...

[morqthana]

* It can't detect earth/neutral reversal.

They could detect a reversal at a socket on an RCD protected circuit.

 

[morqthana]

Not if they have been powered continuosly for weeks/months.
That design gets rather hot in operation, which is ideal for ensuring it has as short a life as possible.

Well unless it's a 3kW floodlight running 24x7...

 

[ebee]

Well we get to the point of any equipment of any size and any price might have its merits to some degree but each man should know his limitations as Clint might say.
Each man should know his equipment limitations too.
Proper test gear used in a properly trained way is a good (the best) way to do.
Using something that only gives limited info can actually be dangerous to rely on, that is the problem,
using a voltstick or a plug in tester has serious limitations and so easy to mislead as to actually worse than than using one at all.
and the infamous "Mains Tester Screwdriver" well that is not really recommended even though it might have been all the rage in the 60s and onwards too.

and yet there are Electricians today who place too much actual reliance on proper testgear too.
such as an all singing all dancing multitester for example.
The most obvious problem is over reliance of the true readings - a loop tester or a voltage tester for example giving a resolution of 0.001 is often mistakenly thought of as an indication of its accuracy .
Never confuse resolution with accuracy - a resolution of 0.001 with an accuracy of +/- 10% is not an indication of accuracy.
Knowing what the readings could actually mean in all circumstances is paramount in all circumstances, with all methods of all of those test meters/plug ins etc etc - throwing a big golden spanner across some mains voltage terminals and wathing the sparks fly and listening to the bang can have some uses but I hope none of us would be daft enough to do that or to ever rely on the outcome.

 

[boringoldcodger]

*** PEDANT ALERT *** PEDANT ALERT ***

easy to mislead as to actually worse than than using one at all.

worse than not using one at all ?

 

[blup]

I had one of those fail on me, ran continuously on a low wattage electric towel rail, It used to heat up whether the rad was on or not. Get a new circuit in that is rcd protected or bring your installation wiring up to date.

 

[ebee]

*** PEDANT ALERT *** PEDANT ALERT ***

worse than not using one at all ?

Hah - I did wonder which one of you would spot that one !

 

[seasickstevie]

Get a new circuit in that is rcd protected or bring your installation wiring up to date.

Not necessarily a circuit, just needs a CU update

 

[mikehammer69]

Well we get to the point of any equipment of any size and any price might have its merits to some degree but each man should know his limitations as Clint might say.
Each man should know his equipment limitations too.
Proper test gear used in a properly trained way is a good (the best) way to do.
Using something that only gives limited info can actually be dangerous to rely on, that is the problem,
using a voltstick or a plug in tester has serious limitations and so easy to mislead as to actually worse than than using one at all.
and the infamous "Mains Tester Screwdriver" well that is not really recommended even though it might have been all the rage in the 60s and onwards too.

and yet there are Electricians today who place too much actual reliance on proper testgear too.
such as an all singing all dancing multitester for example.
The most obvious problem is over reliance of the true readings - a loop tester or a voltage tester for example giving a resolution of 0.001 is often mistakenly thought of as an indication of its accuracy .
Never confuse resolution with accuracy - a resolution of 0.001 with an accuracy of +/- 10% is not an indication of accuracy.
Knowing what the readings could actually mean in all circumstances is paramount in all circumstances, with all methods of all of those test meters/plug ins etc etc - throwing a big golden spanner across some mains voltage terminals and wathing the sparks fly and listening to the bang can have some uses but I hope none of us would be daft enough to do that or to ever rely on the outcome.

Voltsticks are great at what they do

They would only mislead in the wrong hands imo

 

[ericmark]

and the infamous "Mains Tester Screwdriver" well that is not really recommended even though it might have been all the rage in the 60s and onwards too.

Saved me when it turned out the socket was connected to next doors supply, I had turned off whole fuse box, and did not expect the socket could possibly be live. Young then, now always test.

Also without a clamp-on ammeter they are excellent warning when there is a borrowed neutral, even with the clamp-on ammeter, really needs to test down to 1 mA to be sure it finds a borrowed neutral, my old one measured in 10 mA increments, which is really no good, as can't measure the 9 mA permitted back-ground leakage limit, I do wonder why any professional clamp-on would not measure in 1 mA increments or better, but it seems many still will not. Suppose they want you to buy a special one to test RCDs, seems a bit pointless to me, same when they will not measure DC.

Never confuse resolution with accuracy - a resolution of 0.001 with an accuracy of +/- 10% is not an indication of accuracy.

OK, fair enough, I know my clamp-on is not very good with DC, and I would not trust it to show less than 6 mA with a type A RCD, but still better than nothing. Here measuring earth leakage, essential with RCBOs as when measured one needs to add the back-ground leakage to the reading to be sure they will trip at 30 mA, experience very early when the RCD came out, showed how a strain on the terminals can cause a malfunction, so all tests need doing after it has been terminated, so one can't disconnect the circuit to test.

So one pays £20 for the RCBO, then £100 to buy or hire the test equipment, not much difference in buy or hire, as after each hire needs recalabrating. Personally I compare readings with a mates equipment, and if they show the same, I consider it is good enough, if not, one of them will need calibrating.

I selected a socket, at home or work, for a regular test, at least once a week, finding the test equipment is out after a year of use, should mean returning to all tested in that year, that's a lot of testing, so I want to know there is a fault within the week, not having to retest a years work.

But I have never been able to test the built-in test button, OK it trips, but at what current, if our supply is 200–253 volts, to trip at 200 volts, 200/0.030 = 6666 Ω and 253/6666 = 38 mA and likely can't get a 6.6 kΩ so likely 6 kΩ so 42 mA. RCDs go up in size by a factor of 3 times, so as long as less than 50 mA it should not trip the 100 mA RCD feeding the 30 mA RCD, but I know with a 10 mA RCD MK socket it did, so it does say the test button is to test the mechanical tripping, and it does that.

So mine has long gone, but did have something like this in the caravan when touring abroad, mainly to check polarity, when sites had stupid German sockets. But for DIY £50 is reasonable, and we may get people to buy and use one, at £100 no chance.