Super Dumb Question

[Vladimir3000]

Hi,

Apologies for this but im a novice trainee electrician!

Let me start by saying i have read the Electrical Saftey Council best practice guide on Safe isolation but i still have a question!

Do you always turn off the main switch on the CU before opening it?

AND once opened,

can you / do you work on a particular circuit with its individual MCB switched off whilst the other circuits remain on? - if so, is there not a shock risk from various parts e.g, the busbar?

Thanks! (Rather sheepishly)

Blushing

 

[tom1]

turn it all off mate, u get your hands in there u might touch a bit of bare copper, its not worth the risk.

the incommming tails will still be live unless there is a isolator befor the board.

just to add, can anyone say if its posible to get a belt of the nutral bar if the board is live and appliances being used?

 

[SPECIAL LOCATION]

Hi,Apologies for this but im a novice trainee electrician!

Let me start by saying i have read the Electrical Saftey Council best practice guide on Safe isolation but i still have a question!

Do you always turn off the main switch on the CU before opening it?

AND once opened,

can you / do you work on a particular circuit with its individual MCB switched off whilst the other circuits remain on? - if so, is there not a shock risk from various parts e.g, the busbar?

Thanks! (Rather sheepishly)

Blushing

Sorry...

NOT super dumb enough IMHO....

quite logical thought process actually!Applaud Smiley

Do you always turn off the main switch on the CU before opening it?

In an Ideal world..

(or during an assessment)

most probably yes...

in the real world.. it can often be very inconvenient to shut off a whole installation!

can you / do you work on a particular circuit with its individual MCB switched off whilst the other circuits remain on? - if so, is there not a shock risk from various parts e.g, the busbar?

Whilst working on an individual circuit..

yes switched off and LOCKED OFF preferable!!!

and yes.. if the bus-bar cover drops off there is a risk of shock..

but then you can always pop the front cover back on ASAP.

 

[Vladimir3000]

OK thanks very much, always off at main switch then, gotcha.

So if you are installing a new circuit, you would do all sockets / lights /wiring then when thats all finished, the last thing to do would be to connect up at the CU and test then i guess?

 

[tom1]

Sorry...NOT super dumb enough IMHO....

quite logical thought process actually!Applaud Smiley

In an Ideal world..

(or during an assessment)

most probably yes...

in the real world.. it can often be very inconvenient to shut off a whole installation!

Whilst working on an individual circuit..

yes switched off and LOCKED OFF preferable!!!

and yes.. if the bus-bar cover drops off there is a risk of shock..

but then you can always pop the front cover back on ASAP.

its the bits of copper sticking out of neighbouring mcbs that i would end up catching

 

[SPECIAL LOCATION]

its the bits of copper sticking out of neighbouring mcbs that i would end up catching

Shouldn't have bits of copper sticking out of properly terminated conductors.

 

[Vladimir3000]

Sorry Trailerboy,i replied before i saw your answer too!

Thanks so much for your help, what a great (non patronising) forum this is,

However, I will try my best to be more super dumb in future! ROTFWL

 

[kme]

Indeed Vlad.

As Mr. Location says, in an ideal world.........

It isn`t always possible; and, although you`ll comply with EAWR `89 by having the circuit you`re working on PROVEN dead, you can still be in pretty close proximity to other circuits and switchgear that aren`t!!!

Extreme care required.

n.b. I once worked with a spark who had "pond gloves" (shoulder length, thick rubber) ; designed for outdoor ponds. He`d always wear them when going into a CU (even if he`d isolated it first). Admitted, I used to laugh; but he wasn`t going to get an accidental shock, and die!

 

[tom1]

Sorry Trailerboy,i replied before i saw your answer too!Thanks so much for your help, what a great (non patronising) forum this is,

However, I will try my best to be more super dumb in future! ROTFWL

u should see some of my questions mate,

no shame in asking, itss better than burning a house down

 

[Vladimir3000]

Ha Ha, at my level of knowledge i think i'd need waders as well!

; \

 

[SPECIAL LOCATION]

u should see some of my questions mate, no shame in asking, itss better than burning a house down

hmmmmm!

Actually...

Come to think of it....

Pyromaniac, I think Burning a house down may be fun! ] ] ]BlushingROTFWL

 

[tom1]

Shouldn't have bits of copper sticking out of properly terminated conductors.

mine dont, not even in acssesories, but when i take a lid off cu some one will have left 3 or 4 mil sticking out.

it does put u under presure from residents or other trades, i get some **** when the powers off, but i just know i will end up catching some thing and i have small hands

 

[tom1]

hmmmmm!Actually...

Come to think of it....

Pyromaniac, I think Burning a house down may be fun! ] ] ]BlushingROTFWL

just make sure u cover your tracks, arson can carry heafty penilties

they will find traces of flammable liquids

 

[SPECIAL LOCATION]

mine dont, not even in acssesories, but when i take a lid off cu some one will have left 3 or 4 mil sticking out. it does put u under presure from residents or other trades, i get some **** when the powers off, but i just know i will end up catching some thing and i have small hands

"take a lid off cu some one will have left 3 or 4 mil sticking out".

Applaud SmileyApplaud Smiley

thats true....

3 or 4 bl00dy inches in some!!!! :_| :_| headbang

 

[kme]

Why have you been to my jobs???????

bar stewards Grrrrrrr

 

[ianmacd]

If its a new site where I have not removed the cover on the board before then I will try and isolate to be safe as you can never tell what wires may have popped out and be waiting to ping out at you. You can usually tell if a DIY'er has had at the board before though (why do they never use the correct tools for the job they are doing?) so usually they are the most suspect.

If in any doubt, isolate and be safe.

Ian.

 

[revjames]

I was working in a block of 43 rooms in a college campus. A very arrogant painter was working in the same place as me and insisted on having his stereo on VERY loud. I politely asked him if he could please turn it down. He turned it up even more. I went into the switchroom (I had the only key) and turned the whole building off. There were a few complaints as a few residents had computers on but it was worth it. So yes always turn the CU off especially if there are obnoxious painters with large stereos!

 

[a1]

"take a lid off cu some one will have left 3 or 4 mil sticking out". Applaud SmileyApplaud Smiley

thats true....

3 or 4 bl00dy inches in some!!!! :_| :_| headbang

Why have you been to my jobs???????bar stewards Grrrrrrr

But you did that so the conductor can disburse its temperature better, and as a result - the resistance came down.

 

[Badger]

I was working in a block of 43 rooms in a college campus. A very arrogant painter was working in the same place as me and insisted on having his stereo on VERY loud. I politely asked him if he could please turn it down. He turned it up even more. I went into the switchroom (I had the only key) and turned the whole building off. There were a few complaints as a few residents had computers on but it was worth it. So yes always turn the CU off especially if there are obnoxious painters with large stereos!

i hope the computers where not damaged in any way... as id hate to see you insurance bill

 

[revjames]

i hope the computers where not damaged in any way... as id hate to see you insurance bill

It was back in 96 and the summer hols so most students gone home, no damage occurred as far as I know except the pride of the painter was hurt. He stormed off to the centre manager!