where is the line?

[murdock]

while doing this and identifying issues with the electrical installation...there was an 18 month old little boy running around the garden ans it got me thinking.

just remeber we are talking about an 18 month old kid...who doesnt know about the danger of electricity...and also remeber the owner has just moved in so he doesnt know about all the little tricks the electrical inspectors can get away with...so he doesnt know that the wires sticking out in his garden are actually live...he also doesnt realise how dangerous one part of his installation is either which i forgot to mention...where they have switched off a circuit breaker and told the new owner as the previous owner was leaving...he mentioned that the new owner that he shouldnt switch on the one circuit breaker which was down because there is a fault on the circuit.

yip i know you are saying why did i get involved in this k*k again because it is a friend who needed some advice.

the new owner went to a lot of trouble to make sure his old house was safe and now he moves into a new house and has a list a page long og repairs...that why i tell people if you buy a house ge tthe installation checked by your own electrician...from next year i will offer this service to everyone not only my customers....i will just come in...do a visual inspection and advise if i feel the installation has been checked and if the COC is in fact valid or if a full investigation is required...for a small fee of around R500

[murdock]

Not necessarily barefoot, normal footwear will usually pass 30mA @ 220v unless it's bone dry.
You're right though, if the idiot is standing on an insulated mat or wearing neoprene Doc Martens then there will be no fault current and the earth leakage will just see him as a load and not trip. If he holds one wire in each hand with suitably moistened fingers then the current that flows through his body would be more than sufficient to defibrillate him and send him into cardiac arrhythmia.
The standing on a rubber mat scenario is a similar problem to circuits with high Zs which develop insulation problems and aren't effectively protected by RCD's. This is common with TT earthing systems where fault currents may not reach the 30mA tripping threshold.

let me try understand this statement...so you saying working on a fibreglass ladder is not always the brightest solutions...

[Mark Atkinson]

Wow, I didn't realise so many of TFSA's most active members were in the electrical game.

*Headache!*

[murdock]

construction industry is slow...we got nothing better to do with our time

[Mark Atkinson]

I thought I'd gotten rid of voltages and mA's and circuits when I left matric!

Curse you people for bringing back all those horrible memories!

[Dave A]

With all this lousy outside wiring on a plug top, they sure must get a lot of nuisance tripping when it rains.

he mentioned that the new owner that he shouldnt switch on the one circuit breaker which was down because there is a fault on the circuit.

Sometime I think the electrical industry gets too focused on just compliance issues.

If the fault isn't a compliance issue; if it's a maintenance issue, risk and benefit commonly pass with occupation. It is entirely possible the seller is responsible for the repair required -especially as the seller was clearly aware of the problem.

[AndyD]

let me try understand this statement...so you saying working on a fibreglass ladder is not always the brightest solutions...

If you're going to grab the live and neutral simultaneously then a fibreglass ladder will stop the earth leakage from tripping.

There was a thread a while ago where I questioned exactly how effective earth-leakage breakers were at saving lives. This is one scenario where they wouldn't save your life.

[murdock]

If you're going to grab the live and neutral simultaneously then a fibreglass ladder will stop the earth leakage from tripping.

There was a thread a while ago where I questioned exactly how effective earth-leakage breakers were at saving lives. This is one scenario where they wouldn't save your life.

just thinking off the top of my head (which i seem to do more than not ) wouldnt it be better to use a steel ladder which is earthed?

and after making that statement this could be a problem if there is no earth leakage baecause you would be the closest path to earth

[daveob]

just thinking off the top of my head (which i seem to do more than not ) wouldnt it be better to use a steel ladder which is earthed?

I got a steel ladder - it has thick rubber feet on all the legs to stop it from slipping - so I suppose that's defeating the purpose of the steel ladder ?

[AndyD]

Coming into contact with the L + N simultaneously whilst being completely insulated from earth isn't a very likely scenario, it could happen but it shouldn't. If you do then it means you didn't isolate and test the circuit before working on it which is your own stupidity as an electrician or even as a house owner. If a customer comes into contact with the power then there was something non-compliant about the installation which is their responsibility.....unless it was made that way by a qualified electrician and signed off.

Electricity, as with gas or refrigeration will always have the potential to kill or injure no matter how it's installed, that's just the nature of the beast.