Odd RCD problem

[ban-all-sheds]

I believe it varies by area, according to how exchanges are arranged. We really need Pauc_C (PBC_1966) who knows the history of all this back-to-front.

I have to say that nearly all of my experiences have been of the situation as I described. Indeed, if you go back one step further in London, from 0203/0208/0207, through 0171/0181 to plain old 01, I seem to recall that anyone in London could dial anyone else in London without using the '01' - but maybe time/age has distorted my recollections!

Do you remember the old "local" dialling codes, pre STD? So, for example, you could dial an old 5 digit number in High Wycombe from a nearby town by using '5' as the dialling code. When STD came in the 5 got subsumed into the actual phone number.

 

[ban-all-sheds]

It should be possible to 'reset' an RCD (push the lever up into the 'on' position) whether or not anything is connected to it (load and/or supply side) - so 'loose' etc. connections should not make any difference. If the device cannot be 'reset' when nothing is connected, one would normally automatically assume that the device was simply 'dead' (mechanically). However, the OP tells us that if a load is connected, then it magically becomes possible to reset it - which, to mind mind, is pretty bizarre!

Actually, isn't it reasonably common for it to be the other way around, i.e. you can't reset an RCD unless there is no load on it?

 

[oldbutnotdead]

STATUS UPDATE- thanks everyone for your input, I've been busy sanding doors and throwing woodstain at them- v dull but necessary...

Anyway, tested John's hypothesis (toggle needing to be pushed all the way down before it would reset) and couldn't get the original issue to replicate. RCD now resets perfectly every time on no load (all MCBs off) or on any combination of loads. Doesn't matter whether I drop the RCD via the TEST button or by moving the toggle.

John- when I had the issue, I could move the RCD toggle to ON, my voltmeter would show 240v at about half throw but then would drop to zero at fully ON. Under those circs (toggle and visual indicator in the ON position, no volts at the output side) the TEST button did nothing.

Odd, very odd. Place is still under construction (tend to shut the power off at night except to the alarm), if the fault recurs I'll give CED a ring and see what they reckon.

Again, many thanks for the interest. Pretty certain there isn't an N-E fault- insulation resistance readings are all off the scale on my trusty wind-up Megger.

 

[oldbutnotdead]

Actually, isn't it reasonably common for it to be the other way around, i.e. you can't reset an RCD unless there is no load on it?

Ahh, my habit of working (comes from dealing with audio gear a lot I suspect- power stuff up in stages rather than with One Big Switch. But never met one that wouldn't set with a load on.......

 

[oldbutnotdead]

Do you remember the old "local" dialling codes, pre STD? So, for example, you could dial an old 5 digit number in High Wycombe from a nearby town by using '5' as the dialling code. When STD came in the 5 got subsumed into the actual phone number.

Never mind that, am I the only one old enough to remember bypassing the coin mech on Button A button B payphones by banging out local exchange codes on the receiver rests? Where I lived (in Somerset) the main exchange was in Wells, to get to the villages around us (we were 85) you needed (for instance) 87 for Batcombe, 86 for Evercreech, there were many others, in fact we used to get a Dialling Codes supplement with the phone book. We were near an exchange boundary so to get to Frome (without paying) you needed to know the local code from us to Wanstrow and then the local code from Wanstrow to Frome. And then tap it all on the receiver rests........happy carefree days.

And now you can Skype anywhere in the world for nowt...... </old git>

 

[JohnW2]

Actually, isn't it reasonably common for it to be the other way around, i.e. you can't reset an RCD unless there is no load on it?

Quite so - usually because 'the load' has a fault!

However, I'm coming to suspect that many of us (certainly including me), other than JohnD, may have misunderstood - because it now sems that the 'failing to reset' did not mean that 'the lever would not stay up' but, rather, that when it was 'up' (and staying up) the RCD was not establishing an electrical connection between supply and load sides.

Kind Regards, John

 

[oldbutnotdead]

Quite so - usually because 'the load' has a fault!

However, I'm coming to suspect that many of us (certainly including me), other than JohnD, may have misunderstood - because it now sems that the 'failing to reset' did not mean that 'the lever would not stay up' but, rather, that when it was 'up' (and staying up) the RCD was not establishing an electrical connection between supply and load sides.

Kind Regards, John

Yup, thats exactly what it was doing the other night- but not now. Grrrr. Well, not really grrr cos it is working properly but grrr why did it play up?

 

[JohnW2]

Do you remember the old "local" dialling codes, pre STD? So, for example, you could dial an old 5 digit number in High Wycombe from a nearby town by using '5' as the dialling code. When STD came in the 5 got subsumed into the actual phone number.

Indeed. I was mainly in Greater London (Harrow) pre-STD and, if my memory serves me, we just had the 3-digit 'exchange code' (427, which had originally be HAR, for Harrow) followed by the 4 digit number. When STD came along, they just stuck 01 in front of all that.

Kind Regards, John

 

[ban-all-sheds]

We were near an exchange boundary so to get to Frome (without paying) you needed to know the local code from us to Wanstrow and then the local code from Wanstrow to Frome. And then tap it all on the receiver rests........happy carefree days.

Can't see how that would work - the exchange equipment couldn't tell the difference between the pulses from the rest and the pulses from the dial, which is why you could "dial" numbers that way, and it wasn't going to behave differently, nor, surely the mechanism in the payphone - once connected, however you got the number to the exchange, surely the coin mechanism would kick in?

 

[JohnW2]

Yup, thats exactly what it was doing the other night- but not now. Grrrr. Well, not really grrr cos it is working properly but grrr why did it play up?

Now that I actually understand** what you were describing, I have to agree with those who, early on, suggested that it's just a dodgy RCD - which probably ought to be replaced, even if it seems to be working OK at present. If it's resulted in dodgy connections from supply to load side once, it could do it again - and, as some have suggested, that could be bad news.

** to be clear, when someone says to me that an MCB, RCD or RCBO "won't reset", I take it to mean that when they try to push the lever up, it won't stay up.

Kind Regards, John

 

[securespark]

Where's my whiskey.

I don't drink alcohol any more. Can you have one for me?

 

[securespark]

I seem to recall that anyone in London could dial anyone else in London without using the '01'

Certainly could in the early 70's.

Same back then as now in Manchester and 0121 (B'ham), 0131 (E'burgh), 0141 (G'gow), 0151 (L'pool) and 0191 (N'castle / S'land / D'ham) as far as I am aware.

I am on the 440 exchange and can dial my Mum (432) and my Dad (434) and indeed any Manchester number
(0161) XXX XXXX without using the bracketed code.

 

[DaveHerns]

You have to use the full number if using a mobile.

 

[securespark]

if the fault recurs I'll give CED a ring and see what they reckon.

Change it now. It has exhibited dodgy behaviour before. It will happen again. It is faulty. Get it swapped out with a new replacement.
Give CED a ring on 0208 503 8500.

Oh Christ, what have I done....?

Actually, isn't it reasonably common for it to be the other way around, i.e. you can't reset an RCD unless there is no load on it?

Yes, the older MEM RCD's with the tennis racquet lever are like that. You have to knock off all the individual MCB's before it will latch.

 

[securespark]

You have to use the full number if using a mobile.

They were thin on the ground in 1972...