Electrician and QS on trial for death of woman

[rompling]

I Know its been posted about before but it seems the trial has begun ....
Very sad
Emma Shaw electrocuted 'because electrician was UNQUALIFIED' | Mail Online

 

[nickblake]

Thought id add a pic of a situation I came across new consumer unit all tested out with no faults just adding a bond cable and moved some pipes in a trunking and an almighty great Bang it was caused by a screw through a cable just touching the live , you cant pic this up on tests it tripped , if it was shear negligence like another recent job i did where on testing i found no earth on the ring mains caused by 9 penetrative faults on the circuit then they deserve all they get , I had my assessment yesterday and i brought this fault up and said how can you test for a screw or nail touching just the live answer you cant as it may not show up

 

[rompling]

In the coming days we will hear all the evidence and I'm not saying this happened here but - I have crossed paths with many so called electricians who do no insulation testing and when I question them they say" if there is a fault it will knock out the mcb or rcd " - hopefully this tragic case will educate them that ALL the tests have to be completed - if at the very least to protect themselves and others in the courts

I really hope the £100 1/2 hour EICR contractors read this and still feel confident when they issue a certificate

 

[southsea1201]

Less than 20mA can kill if it is prolonged for a number of seconds. It is interesting to not that when on the 17th edition course our lecturer told us metal partitioning with T & E cables running through it MUST be earthed. Alternatively armoured cables should be used.

Now I wonder how many builders know this? and that they should call in a sparky before cladding the metal. I wonder whether the manufacturers of this partitioning include this advice in their erection instructions.

In this case it is conceivable that a proper IR test would not have highlighted the problem.

 

[tazz]

Less than 20mA can kill if it is prolonged for a number of seconds. It is interesting to not that when on the 17th edition course our lecturer told us metal partitioning with T & E cables running through it MUST be earthed. Alternatively armoured cables should be used.

Now I wonder how many builders know this? and that they should call in a sparky before cladding the metal. I wonder whether the manufacturers of this partitioning include this advice in their erection instructions.

Good point on builders, and this is my comment on milli seconds and not seconds

 

[Guest111]

If the studwork wasn't earthed and assuming that the screw only nicked the live conductor then I cannot see how it would show a fault under test,also it may not have tripped an rcd due to their being sufficient resistance to prevent current flowing to earth.We've all seen examples of this,the classic is were someone puts a drill into a cable then bangs the plug and screw in to fix a shelf,it may trip something initially but once the drill is removed everything's back up and running.The question needs to be asked as to whether, given the increased use of this metal system of studwork if there is a need for bonding all structures of this type back to a known earth.But them again how far do you go? Do we go back to the old days when even metal window frames were bonded?

 

[tazz]

In other words back to the crazy 15th edition, and bond any think thats metal

 

[Guest111]

In other words back to the crazy 15th edition, and bond any think thats metal

Oi what was wrong with the 15th? I trained to that if you dont mind,back then we had a simple philosophy "if it don't move bond it,if it moves find out why". lol

 

[tazz]

But back to these fantastic rcds....really the idea is that this poor women on passing 30mA, should have tripped this rcd in milli seconds....if all all bonding and initial earthing is in place.....or an I missing something basic here...I am getting old...lol

 

[Badged01]

Also to add why isn't the boss of the company in court?? .

Because the QS (the assessed competent and trained electrical supervisor) is discharging his duties for him, checking all the work has been done correctly and signing all relevent paperwork to this effect! The bosses shoulders have sloped .......

 

[Badged01]

But back to these fantastic rcds....really the idea is that this poor women on passing 30mA, should have tripped this rcd in milli seconds....if all all bonding and initial earthing is in place.....or an I missing something basic here...I am getting old...lol

That would be my understanding too, if fitted and working!. Though even assuming it tripped somewhere around the 30mA mark the human body reacts differently to it depending on the person. 40mA might not bother me but 20mA may kill someone else ........

 

[tazz]

That would be my understanding too, if fitted and working!. Though even assuming it tripped somewhere around the 30mA mark the human body reacts differently to it depending on the person. 40mA might not bother me but 20mA may kill someone else ........

Hence the reason we test rcds in milli seconds.....I personally think the timing is one very important factor of rcds

 

[southsea1201]

I think we may find out an RCD was involved, 30mA is way to high, 10mA would have deffo saved her life. As she was kneeling it is fair to assume letting go was going to be a problem. Really highlights the fact 10 mA RCBO's may be the future in a domestic situation.

 

[Guest111]

As we are taught there are a variety of factors that can affect it,if a person is wet then they will be more vulnerable to a current flowing through their body plus theoretically is it not possible for an extremely high current to flow in those few milliseconds before an RCD can react?All the tests that decided on the figures for RCD values are based on theory,they never actually did any test on humans did they?so we don't actually know what the safe values are for certain.

 

[sparks1234]

Very unfortunate incident, I'm sure there are many other scenarios which could lead to many different injuries but they haven't come to light because no-one has been hurt. As previously said, there is nothing to say this would have come to light in testing and perhaps the installer has been unlucky but I'm sure the courts will decide.
I liken it to the guy driving on the M40 a couple of years ago that fell asleep at the wheel of his can and ended up across a railway track and killing 2 people on the train, most other people get away with it as nothing so serious happens, he was just unlucky and ended up inside, who knows how many other screws are through steel studs, bring back timber.

 

[Badged01]

I think there has been a study done somewhere (maybe not on humans but feel free to use terrorists!) that suggested 10mA everybody could tolerate and 40mA was the maximum. Depending on the age of the person, physical condition, environmental factors such as water etc ........

30mA was then chosen as the setting that best compromised safety of the person(?) v nuisance tripping if set at 10mA.