Bang!

[Delboybully]

So I go to a job a couple of days ago in a small shop. One of the things to do is fix an RCD that isnt working in a dual RCD board (not that neat but ok, no labels), everything works but if you turn the RCD off it doesnt disconnect the supply to the 4 MCBs it covers. Also the test button doesnt work. Take the cover off the board and the RCD isnt bypassed, it looks like it has failed closed.

I do a quick Ze, turn off the MCBs, RCDs and the main switch, test for dead and replace the RCD. I then power up and the replacement RCD trips. So I then start doing combined IR test L+N to E for each circuit to find the offending circuit. MCBs 1,2 and 3 or ok

Which leaves circuit 4, I connect my jump lead to neutral and the live and BANG!!!!! Nice pirotechnics with a few bits of hot metal spraying around!
Luckily my jump leads have a plastic covering on them or I could have got a belt!

I can tell you I wasnt expecting that. Luckily my jump leads have a plastic covering on them or I would have got a belt! My apprentice missed the fireworks as he was getting stuff from the van but he was impressed with the jump lead afterwards with a bit missing and the charring on the live cable

So I do some more investigating and it turns out the cable coming into the MCB was live and coming from the upstairs flat and was feeding the other 3 circuits in the shop through the bus bar. The guy in the flat above (luckily he was in) told me he has been getting electric bills of roughly a grand every 3 months, no wonder he had been paying for half the electric bill for a small cafe.

Now I followed the safe isolation procedure as I always do but this still happened. I phoned the Elecsa technical helpline and the guy said you followed the safe isolation procedure and its just one of those things you occasional see. He suggested waving a volt stick around the board in future. I then needed to phone the technical helpline again today on another matter so I asked the new guy the same thing, he again said that there isnt much you can do about these things.

I am one of the hated 5WWs, been doing this for approx 2.5 years. I am prepared for a slating, however I would be interested to learn how any of you would of approached this problem and would you of ended up in my situation. Obviously I followed the correct isolation procedure but still ended up in an undesirable spot. Any suggestions would be appreciated

Del

 

[dazza1981]

Well done to the op for sharing this, Im qualified but learning every day and this certainly got me thinking.
I like most sparks have never tested every mcb for dead and not in my AM2 or any other exams during safe isolation was i made to test every circuit for dead once the main switch had been isolated and verified as dead.

 

[guest119]

I think the point is being missed here.
The guy shouldnt have been anywhere near a job like this.
A jib spark is not supposed to be able to work alone nevermind a Electrical Trainee, need to be approved spark for that.
As for the apprentice training, poor lad!

Boydy

 

[dazza1981]

So a jib gold card electrician cant work alone??

 

[MDJ]

So a jib gold card electrician cant work alone??

Hi daz, no idea what the rules are today, but in the early eightees a JIB electrician was classed as someone who could carry out electrical installation work correctly to BS7671 under supervision, only an approved at the time could work alone, that said, today I believe 17 days is the legal requirement lol

 

[southsea1201]

So what you're saying Boydy is that all experienced sparks wouldn't have made the same mistake? I doubt that 100%. Who are you to say his level of competence is not up to this job. Some Electrical Trainee have qualifications that would make your eyes water. Most of them in my city tend to be ex.navy and dealt with far more technical problems than this. Cut the guy some slack...he did what many would have done.

 

[dazza1981]

Hi mate i did not know that, i do have my approved sparkies card but only recently got it.
Saying that i did a full apprenticeship and did the whole college route whilst on the tools but i was working on my own majority of the time as its the only way to gain confidence and experience and learn IMO. ( providing a supervisor has checked your work is ok )

 

[guest119]

So what you're saying Boydy is that all experienced sparks wouldn't have made the same mistake? I doubt that 100%. Who are you to say his level of competence is not up to this job. Some Electrical Trainee have qualifications that would make your eyes water. Most of them in my city tend to be ex.navy and dealt with far more technical problems than this. Cut the guy some slack...he did what many would have done.

And the legal implications are.....?

Boydy

 

[southsea1201]

Clearly if his works doesn't meet the requirements of BS7671 and there's a mishap then the sh&t hits the fan....the same would apply to the most experienced man.

...and I'd also be confident that the OP has resolved the issues on this site

 

[dazza1981]

For roughly 3 years i have been working unsupervised being just a mere jib gold card installation spark up until i got approved status couple of months back.Please dont ring the police on me lol.

 

[HappyHippyDad]

Sorry Delboy, I feel bad about saying this and I never thought I'd speak out against Electrical Trainee (seeing as though I am one), but we are simply not allowed to work outside of the domestic arena. We are 'domestic' installers and should not be undertaking electrical work within a shop.

 

[guest119]

Clearly if his works doesn't meet the requirements of BS7671 and there's a mishap then the sh&t hits the fan....the same would apply to the most experienced man.

...and I'd also be confident that the OP has resolved the issues on this site

Its not about bs7671 for goodness sake man!
Its about being qualified to do the task, experience, risk assess, methodoligy, supervising young persons etc etc.
Yes we all make mistakes but you need to be qualified and suitably experienced to do the task.
Are you familiar with common law? Thou shalt not hurt, endanger, kill another by your actions or inactions/omittions.

Boydy

 

[southsea1201]

Fair play with your comments Boydy, but in this instance I think the OP approached the job professionally and was a victim of something unforeseen that would have caught many out. He was probably aware that each of the properties had its own cutout. He had made an assumption that many of us would...ie that with the main switch of the board in the off position (and tested to boot) that he was ok to IR test.
I don't think it is helpful to attack his ability and competence when he has been the victim of a situation that even the most experienced man could easily fall into. His post is exactly what you want on this forum, it helps the knowledge pool and makes all of us think twice about taking anything for granted.

 

[m top]

Sorry Delboy, I feel bad about saying this and I never thought I'd speak out against Electrical Trainee (seeing as though I am one), but we are simply not allowed to work outside of the domestic arena. We are 'domestic' installers and should not be undertaking electrical work within a shop.

If it's single phase what's the difference as long you understand the cuircuit design why not core principle no different?

 

[Deleted member 9648]

Totally agree with the comments that the OP was pretty much blameless on this one. 100% certain it would have caught me out as well.

 

[ifindoubtdont]

I've been at it for 35yrs and can honestly say "You learn something new every day." That's how you gain experience and you very often say "Oh bugger, I won't do that again."