Basic safe isolation question.

[D00DY_T00DY]

Aaaaaaaand here you go, a battery powered coffee machine, you asked, makita provides!
hahahaha
Makita UK

wow. Did not expect that. Suppose I'll have to show up to work tomorrow... Well later. Those big shot companies always s**t on the little guys. Ruined my million pound idea *sob*

 

[pennychew]

Most of my jobs I have free tea,coffee hot chocolate as many doughnuts as I can eat, and quite often a delightful young lady to make them for me! Soz lads!

 

[SirKit Breaker]

Thanks Pete, Archy I've been studying the safe isolation procedure.
I'm pretty sure most of it has sunk into my thick skull

I'm asking the main live feed to the Consumer is still live.
I was getting a reading with my voltage tester telling me it was live.

You don't have a thick skull!You are a trainee, you are asking because you don't know, this is normal, and it is the right thing to do. Those with the thick skulls have all been killed or injured because they didn't find out and guessed wrong.

Anyway you asked so i will give you the correct way.

Identify circuit to be isolated.

Switch off circuit (Trip breaker/pull fuse).

Fit a suitable isolation device and lock off

Using an approved voltage indicator and proving unit.

Prove voltage indicator with proving unit, it should light up.

Using voltage indicator test each pole to every other.

3 steps if single phase L-N, L-E, N-E

6 steps if 3 phase no neutral L1-L2, L1-L3, L2-L3, L1-E, L2-E, L3-E.

10 steps if 3 phase and neutral. Same as 6 step plus these 4.L1-N, L2-N. L3-N and N-E.

Voltage indicator should not light.

Reprove voltage indicator with proving unit it should light up.

You have now completed "Safe Isolation" to the standard required under the Electricity at Work Regs.

A known live supply can be used if you don't have proving unit.
If you don't have a voltage indicator and proving unit, then buy one.

You cannot use a multimeter of any kind to carry out safe isolation for 2 reasons. It is not the correct instrument because it is not a Voltage indicator, and it can be selected to the wrong range or setting, which can lead to interpretation of wrong results and you getting it all up your arms.

if you don't safely isolate properly, you can and will get prosecuted if you get a shock and live to tell the tale. You will be asked some awkward questions from people who you would rather not be interviewed by, the local A&E wont think you are clever, and you certainly wont be laughing about it in the pub, but the local undertaker may thank your family for the business....

It isn't rocket science but it needs to be done right.


Enjoy.

 

[telectrix]

You don't have a thick skull!You are a trainee, you are asking because you don't know, this is normal, and it is the right thing to do. Those with the thick skulls have all been killed or injured because they didn't find out and guessed wrong.

Anyway you asked so i will give you the correct way.

Identify circuit to be isolated.

Switch off circuit (Trip breaker/pull fuse).

Fit a suitable isolation device and lock off

Using an approved voltage indicator and proving unit.

Prove voltage indicator with proving unit, it should light up.

Using voltage indicator test each pole to every other.

3 steps if single phase L-N, L-E, N-E

6 steps if 3 phase no neutral L1-L2, L1-L3, L2-L3, L1-E, L2-E, L3-E.

10 steps if 3 phase and neutral. Same as 6 step plus these 4.L1-N, L2-N. L3-N and N-E.

Voltage indicator should not light.

Reprove voltage indicator with proving unit it should light up.

You have now completed "Safe Isolation" to the standard required under the Electricity at Work Regs.

A known live supply can be used if you don't have proving unit.
If you don't have a voltage indicator and proving unit, then buy one.

You cannot use a multimeter of any kind to carry out safe isolation for 2 reasons. It is not the correct instrument because it is not a Voltage indicator, and it can be selected to the wrong range or setting, which can lead to interpretation of wrong results and you getting it all up your arms.

if you don't safely isolate properly, you can and will get prosecuted if you get a shock and live to tell the tale. You will be asked some awkward questions from people who you would rather not be interviewed by, the local A&E wont think you are clever, and you certainly wont be laughing about it in the pub, but the local undertaker may thank your family for the business....

It isn't rocket science but it needs to be done right.


Enjoy.

very concise, but you missed out steps 1. and 2.

1. boil kettle.

2. make brew.

then proceed as your post. :49:

 

[newtothis]

SirKit Breaker thanks for the detailed step through.
I have all the testing kit & lock off.

I still have the live incomer, is that considered safe as long I don't touch it and put the test probes at the top of the mainswitch.
I've been taught to use mini croc clips to link the busbar to cpc etc to save time on IR testing. Would I be likely to see sparks fly ?

I know in theory I could request the DNO to fit an isolator, I'm not going to though.

LOL Make a brew, goes without sayin'

 

[pennychew]

As long as the circuit you are working on is isolated then it's safe. Like you say one side of the main switch will still be live but you can use this side to prove your voltage indicator if you don't have a proving unit, and also for testing your Ze

The only ways to completely make the CU safe are to either pull the main fuse (which you're not supposed to do) switch off an existing isolator or request an isolator fitting by the dno, there's no way this would be practical on every job.

If the main switch is off the busbar will be isolated so you won't see any sparks when connecting a crocodile clip onto it, I can't think why you would put a link between the busbar and cpc to do an IR test though?