Anyone come across this!

[hoppy]

Hi, was doing some testing today and disconnected the wrong earth, but I got a shock, so I tested it to the met and got 121v, it was the lighting circuit! When I turned the mcb for the lights off, it disappeared.. I haven't investigated it as it is a council flat and they are responsible for it, it has been reported. I was simply doing a minor works for an additional socket I installed!

the board has an rcd main switch which was not tripping, the rcd is fine I tested it, anyone any ideas what this could be, more out of interest than anything. This is something I have never seen or heard of before


thanks

craig

 

[davesparks]

When you say it has been reported do you mean your unnecessarily placing yours and the occupants of the properties lives at risk has been reported to the HSE under RIDDOR?
Or do you mean you have reported what could be a tiny, perfectly normal, leakage current to the council?

 

[PEG]

Hi fella,i'll be "good-cop"... If you suspected a fault,on the circuit with the recalcitrant earth,then measuring a voltage between it,and the MET,would not be the first test of choice. irate:

 

[davesparks]

Hi fella,i'll be "good-cop"... If you suspected a fault,on the circuit with the recalcitrant earth,then measuring a voltage between it,and the MET,would not be the first test of choice. irate:

Are you suggesting that you would not disconnect the cpc of an energised circuit??? What a crazy idea!

 

[KennyKen]

Should have gone a step further and tried to resolve or at least investigate what the issue was further. Or was it Friday arvo and late for meeting the boys for beers?

 

[hightower]

+1 for making me google the definition of recalcitrant.

 

[snowhead]

+1 for making me google the definition of recalcitrant.

To save me 53 seconds ??

 

[snowhead]

A Rhetorical question;

Why do they insist on installing a cable if it's never going to have current flowing in it?

Hightower,, go for it.

 

[Lucien Nunes]

You can only usefully measure voltage between things that have a circuit between them. When a CPC is disconnected, unless it happens to be casually earthed somewhere, it's unconnected, and can float to any voltage it likes. It has some stray capacitance to the nearby L & N conductors in its cables and to the outside world, some resistive leakage, maybe some leakage from connected appliances, all of which can contribute enough current to produce a voltage across your meter input or give you a tingle. Supposing it was equally coupled to L & N, the potential divider would drive it to a voltage halfway between them. Hmm, what's half of 240?

 

[PEG]

It is still surprising,neh,disappointing,to see the look of wonderment,on time-served sparkies faces,on demonstrating the apparent voltage,on an unconnected circuit which merely runs alongside an energised one.

No amount of reversion to basic electrical theory,can console someone who has spent a grand on an MFT,and sees a figure appear on its' screen,accepting it as a biblical revelation...

...I've gone off topic,again...Nurse! pass me the Tramadol...:drunk:

 

[Lagentium]

I've had that before on a lighting circuit, with low energy lamps fitted, baffled me for a bit!!

 

[davesparks]

It is still surprising,neh,disappointing,to see the look of wonderment,on time-served sparkies faces,on demonstrating the apparent voltage,on an unconnected circuit which merely runs alongside an energised one.

No amount of reversion to basic electrical theory,can console someone who has spent a grand on an MFT,and sees a figure appear on its' screen,accepting it as a biblical revelation...

...I've gone off topic,again...Nurse! pass me the Tramadol...:drunk:

Further to that its a little bit frightening to think they are also disconnecting the cpc of energised circuits apparently at random and without any consideration for the danger they might be placing themselves and the occupants of the property in.

 

[Geordie Spark]

+1 for making me google the definition of recalcitrant.

Well now that you know please share it to save us the bother of looking it up ourselves. :deal:

 

[hightower]

Well now that you know please share it to save us the bother of looking it up ourselves. :deal:

I can't remember and not googling it again. Something to do with non conformity I think.

Edit: fine, here it is: I'll be dammed if you want me to Google obstinately too

having an obstinately uncooperative attitude towards authority or discipline

 

[telectrix]

I can't remember and not googling it again. Something to do with non conformity I think.

Edit: fine, here it is: I'll be dammed if you want me to Google obstinately too

having an obstinately uncooperative attitude towards authority or discipline

and i thought it was to do with water filters. them that remove calcium carbonate from you water.:waving:

 

[PEG]

Yes,it is a wonderful adjective,used by a now,elderly friend of mine,to describe Damien,in "The Omen" :bow:

His other legendary descriptive understatements,include "A bit-of-a handful" for Mao Tse Tung, "Scatty" for Josef Stalin,and "High spirited" for Adolf Hitler.

Ironically,he has only reverted to bad language and profanity,to describe some members of staff at a local Halfords... :willy_nilly:

 

[Geordie Spark]

and i thought it was to do with water filters. them that remove calcium carbonate from you water.:waving:

What the hell would you know about water - unless it's got malt, barley & hops in it????

 

[ruston]

Well now that you know please share it to save us the bother of looking it up ourselves. :deal:

It's a Geordie , Geordie.

a person with a recalcitrant attitude.
[COLOR=#878787 !important]"a stiff-necked recalcitrant and troublemaker"[/COLOR]

And incase you are not convinced.

having an obstinately uncooperative attitude towards authority or discipline.
[COLOR=#878787 !important]"a class of recalcitrant fifteen-year-olds"[/COLOR]

 

[telectrix]

another word for it is intransigent.

 

[telectrix]

and for a geordie's benefit, it's got nothing to do with ford vans.

 

[Geordie Spark]

It's a Geordie , Geordie.

a person with a recalcitrant attitude.
[COLOR=#878787 !important]"a stiff-necked recalcitrant and troublemaker"[/COLOR]

And incase you are not convinced.

having an obstinately uncooperative attitude towards authority or discipline.
[COLOR=#878787 !important]"a class of recalcitrant fifteen-year-olds"[/COLOR]

Yep!! ....... It certainly fits!! :laugh:

Multiplied by ten and you get Tidyboiler. :rolleyes2:

 

[Geordie Spark]

and for a geordie's benefit, it's got nothing to do with ford vans.

Having spent a good portion of my life travelling up & down the A19 at 1:00am in the middle of winter with the heater broken and only one frayed windsceen wiper to shift the driving sleet from the windscreen, the third gear missing, the suspension down on its knees and the exhaust trailing on the road due to the weight of all the gear & crew in the back, only one headlight working and only on dipped beam at that, the clutch that failed in the middle of Durham City in the rush hour, the complete brake failure on the rapid approch to Peterlee roundabout and a whole host of other "issues", I'm here to tell you I know ALL about that particular Ford van!! :32:

(Its predecessor the Thames and successor the Leyland EA 440 didn't fare much better!!)

There's a song ("Living on the A19") about these shenannigans floating about somewhereon You Tube.

 

[telectrix]

that must have been quite recently then. up till 2010 you were still using horses and carts up there,:53:

 

[Geordie Spark]

that must have been quite recently then. up till 2010 you were still using horses and carts up there,:53:

Yer reckon???


Have a shufty of this! ------>> https://en.wikipedia.org/wiki/Armstrong_Whitworth


and this ------->> https://www.google.co.uk/search?q=a...y69IvLAhXB0hoKHatGDaMQsAQIKg&biw=1280&bih=639

I almost forgot this --------->> https://en.wikipedia.org/wiki/Turbinia


and you wonder why I'm PROUD of my heritage??? :smug:

 

[Barry White]

Sam Smith Brewery dray 2 by John Tickner, on Flickr


We still use horse n cart in yorkshire and wooden barrels the goods they pull are far superior than the brown ale up there.

 

[Geordie Spark]

Sam Smith Brewery dray 2 by John Tickner, on Flickr


We still use horse n cart in yorkshire and wooden barrels the goods they pull are far superior than the brown ale up there.

I agree - completely!!

 

[Marvo]

Hi, was doing some testing today and disconnected the wrong earth, but I got a shock, so I tested it to the met and got 121v, it was the lighting circuit! When I turned the mcb for the lights off, it disappeared.. I haven't investigated it as it is a council flat and they are responsible for it, it has been reported. I was simply doing a minor works for an additional socket I installed!

the board has an rcd main switch which was not tripping, the rcd is fine I tested it, anyone any ideas what this could be, more out of interest than anything. This is something I have never seen or heard of before


thanks

craig

The CPC is functional as well as protective, there's likely to be some current flow especially on a lighting circuit that has LED lamps or fluorescents. If disconnected it's going to float at a voltage and I'm not surprised you got something of a shock from it. If you ever do a stunt like this on a commercial or industrial installation it's likely to give you a shock large enough to kill you outright, I've seen >60 Amps earth current on an industrial installation and this wasn't considered a fault current due to the type of steam generators being supplied.

 

[Golden_Boy]

You can only usefully measure voltage between things that have a circuit between them. When a CPC is disconnected, unless it happens to be casually earthed somewhere, it's unconnected, and can float to any voltage it likes. It has some stray capacitance to the nearby L & N conductors in its cables and to the outside world, some resistive leakage, maybe some leakage from connected appliances, all of which can contribute enough current to produce a voltage across your meter input or give you a tingle. Supposing it was equally coupled to L & N, the potential divider would drive it to a voltage halfway between them. Hmm, what's half of 240?

Thats why the analogue AVO is worth its weight in copper sometimes. Nice low ohms per volt, As you drop the range down the voltage reading falls also = high impedance source.

 

[Skimpy Wan]

If you did an low ohms resistance test between r1 & r2 on a dead circuit this would also confirm a high impedance source wouldn't it (or am I going down another dark path)?