Live works,on DB to do or not to do

[cliffed]

what’s your take on working on live DB’S,connecting circuits & installing mcbs.

 

[Dave OCD]

Every situation is different and you weigh up the risk on a job by job basis but I'd always have the main switch off, certainly in domestic there's no reason not to ?

 

[littlespark]

We've all got 1000v insulated screwdrivers, haven't we?

 

[Octopus]

Why can't you turn the CU off ? Especially if you are fitting MCB's?

 

[The Ghost]

I follow the HSG85, especially using the flow chart for decision making. Do a RA, amd MS generally working around that framework. Don't do it if you can avoid it really is the bottom line. If you do have to then make sure you have RAMS.

 

[Andy-1960]

It’s fine until something goes wrong!.. then the HSE get involved and you had better have a very good reason for working live.
If you can .. always turn it off.
Have a look at Regulation14 of the Electricity at Work Regulations.
I was on the receiving end of an HSE investigation many years ago, when one of our electricians was changing an MCB in a board. The replacement was brand new and turned out to be faulty, the resultant explosion left the guy installing it badly burnt.
Customer had said he did not want the power off as it affected his computers.
HSE said no excuse.. we got fined and so did the customer!
We now do not work live and when you explain to the customer he could be in trouble too if something goes wrong, it’s amazing how a window of opportunity to do the work dead suddenly appears!

 

[cliffed]

Thanks for all comments,domestic installs,no problem switching off,but what about offices etc,where it can be a problem.
Always been taught switch off,but I’ve seen many a spark working on live Db’s,is it becoming a norm.

 

[cliffed]

It’s fine until something goes wrong!.. then the HSE get involved and you had better have a very good reason for working live.
If you can .. always turn it off.
Have a look at Regulation14 of the Electricity at Work Regulations.
I was on the receiving end of an HSE investigation many years ago, when one of our electricians was changing an MCB in a board. The replacement was brand new and turned out to be faulty, the resultant explosion left the guy installing it badly burnt.
Customer had said he did not want the power off as it affected his computers.
HSE said no excuse.. we got fined and so did the customer!
We now do not work live and when you explain to the customer he could be in trouble too if something goes wrong, it’s amazing how a window of opportunity to do the work dead suddenly appears!

Thanks,that really does make a decision easier,switch off

 

[Squid]

Thanks for all comments,domestic installs,no problem switching off,but what about offices etc,where it can be a problem.
Always been taught switch off,but I’ve seen many a spark working on live Db’s,is it becoming a norm.

Then its weekend work, double bubble.......... ;o))))))

 

[Ian1981]

It’s fine until something goes wrong!.. then the HSE get involved and you had better have a very good reason for working live.
If you can .. always turn it off.
Have a look at Regulation14 of the Electricity at Work Regulations.
I was on the receiving end of an HSE investigation many years ago, when one of our electricians was changing an MCB in a board. The replacement was brand new and turned out to be faulty, the resultant explosion left the guy installing it badly burnt.
Customer had said he did not want the power off as it affected his computers.
HSE said no excuse.. we got fined and so did the customer!
We now do not work live and when you explain to the customer he could be in trouble too if something goes wrong, it’s amazing how a window of opportunity to do the work dead suddenly appears!

Even if isolated if you restored the power it still would have exploded yes?
Or was the issue the cover wasn’t reinstated before turning on the mcb?
(I’m not advocating live working by the way)

 

[cliffed]

Additional circuits to Live Db’s,should it be planned by your company,explained to the customer,& a time/date to isolate completely,all this arranged before works begin.

 

[littlespark]

I’m not advocating live working by the way

Neither was I,

 

[Dave OCD]

We've all got 1000v insulated screwdrivers, haven't we?

It's not so much the chance of direct contact, more the risk of a short and the resultant nasty flash and bang....

 

[cliffed]

Agree,it also means that after works,another visit may be required to isolate the DB,to make the circuit live.
Adding extra cost & time to the job.

 

[Dave OCD]

Yes it could mean that, but still a lot cheaper than the consequences if it all goes pear shaped.

 

[Andy-1960]

Even if isolated if you restored the power it still would have exploded yes?
Or was the issue the cover wasn’t reinstated before turning on the mcb?
(I’m not advocating live working by the way)

Actually, no, the problem was that busbar termination screw in the MCB which should have been captive wasn’t. As the guy tried to tighten it it went thru the open side of the MCB and touch the neighbouring phase connection which resulted in a direct short between two phases. If the power had been off it would not have happened.

 

[magnoliafan89]

I tend to take the main incoming live out and hold the copper end in my mouth ....boards totally isolated then and safe to use .....

 

[Risteard]

It's worth remembering that there could be the potential for a substantial fault current which could pose serious risk to personnel working on it. It's actually quite a dangerous practise.

 

[cliffed]

I tend to take the main incoming live out and hold the copper end in my mouth ....boards totally isolated then and safe to use .....

Sounds good,is that on a regular basis.

 

[alexander jackson]

If I can I will isolate, most of my work is industrial in nature (non domestic) so if circuits can go dead they will.