Anyone ever "LOCKED" a mcb "ON" by mistake?

[Sparky83]

No?

Neither have i..... but someone i work with (i use the term loosly) has!

The MCB had already been switched off, but for some unknown reason he switched it back on and then somehow managed to get a lock off on it but locked it on instead. But it doesnt stop there....

The reason it was being locked off in the first place was because it fed a big beast of a 110v tranny that was being taken out, it was a 63a supply. So without testing and checking for dead, he started cutting through the SWA cable.......BANG!!!!!!

Luckily for him and the guy helping holding the cable (who aint a sparky anyway) they were both ok, guy cutting got a shock but nothing more. The poor inocent hack saw blade took the brunt of it!

Shocking, literally!!!

 

[nickblake]

Remember the days of the PP3 9 volt battery ,weve just grown up

 

[Knobhead]

To me the first elecrician should have locked off using a MultiHasp, 2nd electrician then adds his lock and so on.....
I've seen an isolator on a large plant with 60+ locks. The isolation can't be removed until the last person has finished.

 

[Plonker 3]

Have a look at hager MCBs it is actually possible to lock them inthe on position.

 

[rocker]

In the 'always test' vein, was doing a CU change on Monday, and luckily (as is often the case in these matters) the service fuse just fell out, allowing me to work safely.
Being a good boy, though, even though I knew the fuse had fallen out, I tested the incoming tails before touching them, and lo and behold, there's voltage. Polarity is OK, so WTF? Well it just so happens that the DNO have put a new service head and meter in an outside cupboard, and instead of removing the old lot and putting in new tails of connecting in a Henley, they just took the incoming phase and jointed it on the consumer side of the fuse. Luckily, as soon as I found the new fuse, it fell out myseriously and all was OK, but it just goes to show, a fuse can fall out before your very eyes but the installation can still be live.

Also, a few weeks ago I was doing some domestic work, and the homeowner was the helpful type. Nice guy, actually. I was working on a shower cable after opening (but not locking off) its MCB. I touched neutral to CPC which tripped the RCD. The homeowner says 'I'll turn it back on', I think 'I really should do this myself' but stupidly say 'OK then' and carry on working. He gets downstairs and shouts up 'I'll turn the one at the end on, but are the ones in the middle meant to be on?'

Now, what I hear is 'there are some MCBs on, is it OK to leave them on and just turn on the RCD?'
But what he means is 'The RCD AND and MCB is turned off. Shall I turn them all on?'

Cue an ungodly noise made by myself, a very blistered middle fingertip, a big bump on the head from when I landed, the shakes and one hell of a bruised ego. My laziness and sheer bloody stupidity could quite easily have killed me. Lucky my boots were tidy. Very lucky. First and last time that happens.

 

[Sparky83]

To me the first elecrician should have locked off using a MultiHasp, 2nd electrician then adds his lock and so on.....
I've seen an isolator on a large plant with 60+ locks. The isolation can't be removed until the last person has finished.

I'd agree but, the first electrician was just checking that it was indeed the correct MCB for the tranny, he at not point told the other guy to just go cut through it, and even if he had it is the electrician whom is going to cut through its responsobility to carry out the proper isolation procedure. If this had of been done then we wouldnt have had to replace our hacksaw blade the next day. I have some very good mate's who are sparkies but i trust no one unless im 100% sure its been isolated.

 

[Sparky83]

Have a look at hager MCBs it is actually possible to lock them inthe on position.

Our DB's are Merlin but as the holes are in the middle of the swtich, they are able to be locked either way, bit of a design flaw??!!

 

[lemau]

so lucky..please put a signage or lock the fuse box after shut off the power..safety first..PREVENT ELECTRIC SHOCK before its happen

 

[Sparky83]

Apparently the mcb will still trip but its beggers belief why he never tested it before taking his hacksaw to it! Just goes to show that age/experience doesnt always mean things get done as they should!

 

[Burnt Fingers]

I like all of your comments - I have always thought I was a wuss testing, locking off then testing again, then proving, then waving a wand etc. Guess I'm not so wussy after all - just sensible.

 

[rocker]

I like all of your comments - I have always thought I was a wuss testing, locking off then testing again, then proving, then waving a wand etc. Guess I'm not so wussy after all - just sensible.

Not wussy mate, not even sensible. Just not suicidal.

 

[vambo]

The mcb would have tripped (broke the circuit) even if it was locked on, they are thermal trips and the switch is just a latch that doesnt force the mcb on. Eitherway it was stupid thing to do.

 

[Stroppy]

I was a good boy a while ago and bought a set of the Hager MCB locks, and a little padlock to do everything properly. Trouble is everything is so loose and wibbly-wobbly that you can still remove the locking device when it is in place and locked. Rubbish!

One way my colleague uses to prevent unauthorised numpties turning your MCB back on is to take out the Line conductor from the MCB, then take out the MCB itself and take it with you!

 

[Knobhead]

Wonderful, now why have you dragged a 2 year old post out of retirement.

 

[Stroppy]

Because I knew it would annoy you.

Anyway why shouldn't I? What is the time limit for comments?

 

[shanky887614]

you would think so wouldnt ya

electrics lesson 1 dont touch live cables but check out this guy apparently 2330l3

http://www.electriciansforums.net/e...ical-regulations/16787-i-got-shock-today.html

cant understand why touching the incoming side on an isolator in a cu would give him a shock

may the lord save us all

you say that but a guy i did the l2 and l3 course with couldnt understand why his lights wernt working (plastic conduit) and when examiner tried to turn off breaker nothing happend

he forgot to put a neturel from board to lights and wired all the browns together, blues together and cpc together.


he was dangerous but they still passed him.


it takes 30secs to tripple check voltage with an indicator stick to make sure cable is dead before you start to cut through it (after safe isolation of course)