Tragic - outcome might be interesting

[bernardgreen]

No what I hope is the leakage will cause the RCD to trip before anyone touches a live part,

There might be no leakage at all before a person makes themselves part of a circuit between Live and Earth

 

[ericmark]

There might be no leakage at all before a person makes themselves part of a circuit between Live and Earth

Agreed, but most times we are looking as water ingress, and often that does cause a trip before touched.

 

[EFLImpudence]

Agreed, but most times we are looking as water ingress, and often that does cause a trip before touched.

But that is not what RCDs are primarily for. Yes, I know for TT etc.

They are for personal protection when the person is the path to earth.

The do not need to be fitted to detect slugs.

 

[Harry Bloomfield]

There seems to be a myth that if you have a RCD you can't get a shock over 30 mA, one can get many amps for 40 mS, OK risk is reduced, but not removed, what we hope is with the RCD it will trip before some one touches a live part, but hacksaw blade through a cable when chasing down a wall which should have no cables, still hurts, I found out hard way, even with a RCD.

The whole point of an RCD, is to quickly disconnect your body under a fault condition, from the live conductor. Its the current and duration which do the damage to the body. Often if you make contact with something live, due to involuntary muscle contraction, you might not be able to let go.

 

[Harry Bloomfield]

I thought it was more the amps that killed from touch, not necessarily the voltage? - people survive being struck by lightning which is high voltage.

It's the voltage, which drives the current through the body and the amount of current available depends on the source resistance/impedance. Another factor, is the resistance of the individual body, and the part of the body which makes contact....

A warm sweaty skin, or wet from a bath or shower, forms a much better conductor, than dry skin contact.

 

[Adam_151]

Sounds somewhat similar to this https://www.bbc.co.uk/news/uk-england-london-55753100 incident which if memory serves proved to be a lack of earthing to the board suppling the lights and the earthed metalwork livened up by a fault

 

[ericmark]

The whole point of an RCD, is to quickly disconnect your body under a fault condition

No the RCD was used to start with to replace the ELCB-v to disconnect the supply when there was a fault to earth as the current involved was not enough to rupture a fuse once we went to plastic water pipes with a TT system. Early ones were type S with a built in delay, and typically 100 mA, it was not until we started to use 30 mS at 40 mS was there any thought of protecting personal, and with the shorter tripping time it can help a lot, but one will still get a nasty belt, and it is hoped it is triggered well before current passes through the human body.

 

[Harry Bloomfield]

No the RCD was used to start with to replace the ELCB-v to disconnect the supply when there was a fault to earth as the current involved was not enough to rupture a fuse once we went to plastic water pipes with a TT system. Early ones were type S with a built in delay, and typically 100 mA, it was not until we started to use 30 mS at 40 mS was there any thought of protecting personal, and with the shorter tripping time it can help a lot, but one will still get a nasty belt, and it is hoped it is triggered well before current passes through the human body.

I repeat - The whole point of an RCD, is to quickly disconnect your body under a fault condition.

 

[securespark]

This is the kettle lead belonging to the elderly lady.
What first caught my eye were the conductors hanging out of the bottom.

Then I saw the cut in the neutral conductor.

I switched off the power as I had a socket to replace in the kitchen. After checking the other side of the kettle socket for dead, I removed the kettle plug.

Not thinking this could get any worse, I opened up the plug.

I couldn't quite believe my eyes!

 

[SUNRAY]

This is the kettle lead belonging to the elderly lady.
What first caught my eye were the conductors hanging out of the bottom.View attachment 313706

Then I saw the cut in the neutral conductor.

I switched off the power as I had a socket to replace in the kitchen. After checking the other side of the kettle socket for dead, I removed the kettle plug.

View attachment 313707

Not thinking this could get any worse, I opened up the plug.

View attachment 313708

I couldn't quite believe my eyes!

And I take it that was still working too?

 

[SUNRAY]

No strain relief or even a grommet, 0ne screw and err 3 singles.

 

[securespark]

And I take it that was still working too?

Oh yeah. In service daily. I put it in the van immediately and went and got the lady a whole brand new kettle.

 

[SUNRAY]

Found during 'I get electrocuted when I use the computer'View attachment 313711

 

[RandomGrinch]

Oh yeah. In service daily. I put it in the van immediately and went and got the lady a whole brand new kettle.

O M G!
Was the strand from around the fuse actually touching the earth pin at the time, or was it being held off by the partitions in the plug top?

The benefit I have from PAT'ing the same areas time and time again, is luckily, the number of surprises like this, tends to decrease over time (although it never entirely disappears).

Post in thread 'Failed PAT' https://www.diynot.com/diy/threads/failed-pat.580522/post-5092548

 

[securespark]

O M G!
Was the strand from around the fuse actually touching the earth pin at the time, or was it being held off by the partitions in the plug top?

As I said, I had been using the lead as a teaching aid. The top has been on and off and the lead handled many times. It wasn't originally shorted on the earth pin, no, but it was shorting to the live terminal, thereby bypassing the fuse.