DONT RELY ON RCD's PLEEEEESE.

[baldsparkies]

We seem to have a lot of young sparkies following the trend that RCD's are some kind of wonder device.
To explain,
An elderly lady has just come out of a 3 day stay in hospital.
Why ??
Because a young electrician had installed a dual RCD board to there property and explained how it protected from electric shock, and how wonderful RCD's were.
It left the old couple with a very mis guided conception that they were completely safe regardless.
The old chap had been decorating and left the light switch hanging by the cables.
One evening his wife went to turn the switch off, accidently put her finger behind it, and made direct contact with a live conductor.
Whilst the RCD did operate. She recieved a nasty shock that resulted in hospitalisation.
Now whilst I appreciate the RCD probably helped save her life.
Please dont for one minute think it will protect a user from an electric shock. IT WONT !!
They are a useful aid towards safety in that they can help reduce the possibility of a fatal shock.
But please refrain from telling people they prevent electric shock, and choose your words wisely.
Sorry guys rant over.

 

[ChrisElectrical88]

But then you have people who still think it's ok to stick a RCD in when a protective device doesn't meet it's disconnection requirements!

 

[telectrix]

It's kind of you to enquire what is what that actually happened. Had you had done so then you'd quickly retract that comment. The world is a big place.

more details would be nice. even if as a warning not to trust other people where your own life/safety is concerned.

 

[Rockingit]

more details would be nice. even if as a warning not to trust other people where your own life/safety is concerned.

I didn't tell the story purely not to hijack the thread!

It was a set of circumstances which you wouldn't normally find in an everyday installation: in touring/events world everything is modular and 'rubber box distro' based - basically a plug and play approach using a mass of heavy ceeform and so on. I was working on an event overseas where there were a whole bunch of brand new brass BC holders on flex been installed (using a 16A ceeform system) into the roof of a large marquee for effect with clear GLS's. Anyway, they didn't work when turned on below at the MCB so up I went up the ladder to have a look, and couldn't immediately see anything wrong so unplugged one and brought it down to ground level. Plugged it direct into another 16A outlet and went and got the meter to see what was on the pins. So I'm holding this thing in one hand, and reach over to grab my test-stick with the other, and brush onto the aluminium edging strip which is fitted onto most flightcases to protect the edges and corners. WALLOP!! It turned out that some wiring-monkeys had gotten their colours mixed up on the cables and the brass BC I had in my hand was wired L to cpc (and I hadn't felt it due to insulated ladders and work boots) and the feed cable onto that dis board had also been cross wired Ph to the E which in turn was also bonded to the cabinet strip). Somewhere in that equation I must have been passing enough to a genuine earth path somewhere to have upset the upstream RCD.

 

[Knobhead]

no....
due to your own incompetance...

so just who told you to handle any 2 phases simultaneously?

come on...this is pis poor practice...

That’s rich coming from you.

The man that fell off a wheelybin!

 

[Silly Sausage]

That’s rich coming from you.

The man that fell off a wheelybin!

Hahahahaahaaa...FULL story, please!!! :smilielol5:
On here will be absolutely fine. :21:

 

[shanky887614]

That’s rich coming from you.

The man that fell off a wheelybin!

So the old fart was ****ed!!!

 

[Fin170]

'Additional protection', better with than without

And a surprising amount of faulty RCDs seem to be down to a lack of routine testing. I've read a few cases of RCDs failing on RCD testing then functionally perfectly well after it has been manually tripped and reset

 

[GMES]

no....
due to your own incompetance...

so just who told you to handle any 2 phases simultaneously?

come on...this is pis poor practice...

Glad to see your putting the practise in for you your new role as a moderator it is coming on a treat Glenn:computer:

 

[netblindpaul]

'Additional protection', better with than without

And a surprising amount of faulty RCDs seem to be down to a lack of routine testing. I've read a few cases of RCDs failing on RCD testing then functionally perfectly well after it has been manually tripped and reset

If the RCD fails on manual test, it fails test.
It must not be put back into service, how can you tell that it will not fail again, it has failed once, once is enough to kill someone.

 

[driverman]

Out of interest....all you guys that carry out EICR ......how many RCD's do you fail as they do not operate within time limits or not at all. I was told recently that 7% RCD's fail! Not good if you are receiving a shock.

 

[GLENNSPARK]

If the RCD fails on manual test, it fails test.
It must not be put back into service, how can you tell that it will not fail again, it has failed once, once is enough to kill someone.

it states quite clearly that if the manual test (test button) fails first time round...then its a fail....
regardless of the 1/2, 1 & 5 values...

 

[GLENNSPARK]

Hahahahaahaaa...FULL story, please!!! :smilielol5:
On here will be absolutely fine. :21:

OK..
what happened was i was stood on a wheely bin to change an outside light..all because the dummy i was working for had left the ladders on another job...
first time it was OK...
then i had to go get something...
got back on the wheely bin and was just running the screws in when it went from under me..
now we all know that wheely bins are not that high but it was the way i fell...
shattered my ankle (both sides)..
i have metal plates on each side and some of the screws fixing it ar 50mm long...
theres something like 12 screws in each side...
all back to normal now but i was off for 8 weeks....
i`m lucky to be walking at all really...and when its damp weather it sometimes plays up...

 

[GLENNSPARK]

Glad to see your putting the practise in for you your new role as a moderator it is coming on a treat Glenn:computer:

like i says...
should work out fine...

 

[Paul.M]

One thing that was impressed upon me during my training is that although there is an accepted resistance for the human body, this can vary dramatically from person to person, obviously changing shock risks at different levels. An older person with a weaker heart for example can be more susceptible to fibrilation at lower amperage levels.
Hence the effectiveness of a 30mA RCD depends on the situation.

GN7 table 1.1 gives the "Total body impedances (Zt) for a current path hand-to-hand" for a human.

@ 225V (from the book) 5% of the population has a Zt of 775 Ohms

50% has 1225 Ohms

95% has 1900 Ohms

Think of these figures when you next get a belt protected by an RCD. I've had a shock earlier this year from another sparks cock up and I must be in the 1900 Ohms range of body Zt, it was a hand to hand shock and I did'nt die BUT the circuit was protected by and RCD and it did'nt trip??? Full test on the RCD and it was fine????


Older people, people with medical conditions etc may still receive a fatal shock. RCD's are not the miracle cure for everyone. Lets get that straight from the start. Yes they are good but they are not to be sold as "a shock free device".

 

[Paul.M]

OK..
what happened was i was stood on a wheely bin to change an outside light..all because the dummy i was working for had left the ladders on another job...
first time it was OK...
then i had to go get something...
got back on the wheely bin and was just running the screws in when it went from under me..
now we all know that wheely bins are not that high but it was the way i fell...
shattered my ankle (both sides)..
i have metal plates on each side and some of the screws fixing it ar 50mm long...
theres something like 12 screws in each side...
all back to normal now but i was off for 8 weeks....
i`m lucky to be walking at all really...and when its damp weather it sometimes plays up...

Glenn, I took the Mick at the time. I wont rib you on here for making a daft decision when you was in a rush. BUT I still find it funny and I will take the Mick at any opportunity you bloody idiot lol, pmsl.