Dangerous Wylex Mcb

[Barx]

Had a rather strange occurrence  today. Was working away (me plus 2 other lads) finishing off a social housing rewire (just like every other day) ; I completed the board change and connected the tails. Switched on the DNO isolator and proceeded to carry out Ze and pfc tests. All ok thus far. flicked rcd's on and pressed buttons to functional test. Then started testing trip times ready for cover going on board. The timing of what happened next was crucial. At one of the point were I turned an rcd back on, one of the others lads was 2nd fixing a light switch. Stripping the cable and happened to be holding line and earth...

He got a belt. Naturally, started having a pop at me. To which my response was 'All the breakers are off, WTF!!!'. Quickly turned everything off and first thing that popped into my mind was the tails must be wrong way round (didn't know it was line that was live at this point, but then thought 'can't be as the tester would have flagged it as reverse polarity on Ze test'. Anyways, a few minutes of testing and diagnosing how this could happen and a fair bit of head scratching, turns out the MCB for the lighting, although it was in the off position, was letting current past. All the others seemed ok, To be honest, this is not something I normally test.

So, be aware, such things CAN happen.

 

[ProDave]

No doubt a fault. how many ohms does the offending MCB measure in the "off" position?

But I am not sure I would have "energised" a new CU (even if all circuits were "off" without at least informing my mate that I was about to do that.

One of the advantages of working alone, is this would never have happened to me.

And am I the only one that would have left the cover off the CU until everything was tested and verified? I would not have even been thinking about the cover at this stage.

 

[Barx]

I did let them know what was going on, but obviously all MCB's off, cables presumed dead. No idea what it measured but think it's in the van so can test it.

Working alone, yes this wouldn't have happened to you, but also, you wouldn't have discovered the faulty part??

p.s. the cover was going on as the tenant 'needed' some power. Most circuits, including rings had bee tested, just lighting to get finished off and I was leaving the CU to go do some conduit work outside.

 

[ProDave]

Working alone, yes this wouldn't have happened to you, but also, you wouldn't have discovered the faulty part??

Very true.

Perhaps a new test we should all do (if you don't already), is turn off all MCB's and measure to ensure the circuits really have turned off.

I thought you were going to post something along the lines of a pre wired split load board had been assembled wrong, so the L feed to the RCD side came from the INPUT to the main switch. So with the main switch off, all the RCD side still had L connected, but not N. I found one like that once.

 

[Evans Electric]

So is this rogue MCB another example of  Electrium's policy of manufacturing at some far flung factory where Quality Assurance is'nt their main concern . 

Wylex, along with Crabtree have an ongoing product call-back in process and TBH Barx , that MCB should be on it's way back to Wylex via the wholesaler .  

I have to say this....... I don't think many of us would have expected that fault .     I've had breakers that don't pass any current when switched ON but not the other way round.    It needs to go back , and Electrium need to know about it . 

Two old and TRUSTED manufacturers who have lost all credibility by closing their UK  operations and going for the cheapo labour , cheap , crapo product which is proving to be dangerous. 

I used Crabtree for years , which is also Denman's Steeple brand , I did my share of the recalls but don't use it anymore . 

I've been in the trade for 300 years , it seems, but only recently do we get faulty goods from the likes of Crabtree, Wylex & now MK .

 

[batty]

I think British Standards would better be informed than electrium. Would electrium actually do anything about it. This could be a serious thing a householder potentially could get killed or even a sparks if he didn't test before touching a live conductor. This sounds very worrying to me. Was it a siemens one?

 

[Jono Pashley]

Am i the only one who verifys mcbs operation as they are fitting them?

 

[Sidewinder]

What about, 612.13.2?

 

[Barx]

What about, 612.13.2?

Is that an ip address??

 

[pewter]

an old fashioned ip address system to give the reference to an old fashioned network in a book

 

[Evans Electric]

What about, 612.13.2?

Functional testing  ...yes .. but its still a rogue MCB  ...how many more are there,  not functionaly tested , awaiting the unsuspecting homeowner/DIYer etc.  

 

[Sidewinder]

Yes, however, this is part of Initial Verification and has been for several editions of the regs now, so, one should be checking this immediately on power up, should one not!

 

[ProDave]

I would still love to hear the test results on this dud one.

Was it a dead short, i.e. 0 hms  when "off"

Or was it some high resistance? still enough to give you a jolt, but not enough to deliver any serious power to energise a load?

 

[Barx]

I would still love to hear the test results on this dud one.

Was it a dead short, i.e. 0 hms  when "off"

Or was it some high resistance? still enough to give you a jolt, but not enough to deliver any serious power to energise a load?

Not been at work today, off out in the morning to fit an alarm so will drop a test on it.

 

[cornish terrorist]

You broke the law by not ensuring that all circuits were de-energized correctly, if you slipped you could have accidently knocked a breaker in the on position potentially killing your workmates, no live testing should have been carried out while other people where still working on it , the locked off board keys should of been in your pocket and I think you are all missing the point here, I certainly wouldn't be advertising my bad practice on this forum

 

[Barx]

You broke the law by not ensuring that all circuits were de-energized correctly, if you slipped you could have accidently knocked a breaker in the on position potentially killing your workmates, no live testing should have been carried out while other people where still working on it , the locked off board keys should of been in your pocket and I think you are all missing the point here, I certainly wouldn't be advertising my bad practice on this forum

Ok point taken. Beat me down alk you like. Arrest me if you shall I have broken the law. Just pretend there was no faulty breaker, the job didn't exist and this post won't for much longer. I give up.

Admin / mods, just delete this thread, I can't be arsed. Try and give people a heads up and I'm in the wrong.

Over and out...

 

[davetheglitz]

What you say makes perfect sense - but a touch self rightious for my taste!. As I'm a one man band this probably wouldn't happen to me -- but we need to talk about these things rather than brush them under the carpet. We've all done things that we're not proud of - often to finish a job when we're tired and stressed - and within this forum we should be able to say what we like so others can learn, I will continue to advertise my bad practice!!!!

You broke the law by not ensuring that all circuits were de-energized correctly, if you slipped you could have accidently knocked a breaker in the on position potentially killing your workmates, no live testing should have been carried out while other people where still working on it , the locked off board keys should of been in your pocket and I think you are all missing the point here, I certainly wouldn't be advertising my bad practice on this forum

 

[ProDave]

You broke the law by not ensuring that all circuits were de-energized correctly, if you slipped you could have accidently knocked a breaker in the on position potentially killing your workmates, no live testing should have been carried out while other people where still working on it , the locked off board keys should of been in your pocket and I think you are all missing the point here, I certainly wouldn't be advertising my bad practice on this forum

If you are going to be self righteous, then please get your grammar right.

It's should HAVE been,  and not should OF been.

Just a pet hate of mine. they obviously don't teach English correctly any more. Okay I'll get my :coat

 

[steptoe]

If you are going to be self righteous, then please get your grammar right.

It's should HAVE been,  and not should OF been.

Just a pet hate of mine. they obviously don't teach English correctly any more. Okay I'll get my :coat

hows your Scots coming on Dave,? 

or do you say

'dinnae ken'

 

[cornish terrorist]

give up then!