Isolation

[JohnW2]

What is a concern is that the post implies that the socket front was removed in order to fit a circuit breaker inside and then closed back up meaning that it would be expected somebody would open up a live three phase socket in order to turn off the mcb.

My understanding is that such was definitely not the intention. As he agreed when I asked him, he was merely using the circuit breaker 'as a JB', with no intention that anyone should open the enclosure in order to turn off the breaker - he acknowledged that switching off at/near the socket was no longer possible, and was relying on the switch/isolator 'on the machine' for that purpose.

Kind Regards, John

 

[JohnW2]

Unplugging a machine alone is also not a suitable method of isolation unless a plug lockout is used with the key to the lock being under the control of the owner of the job in hand.

That is true, but is no more true of isolation by means of a plug/socket than is the case with any method of isolation.

Kind Regards, John

 

[bhm1712]

My understanding is that such was definitely not the intention. As he agreed when I asked him, he was merely using the circuit breaker 'as a JB', with no intention that anyone should open the enclosure in order to turn off the breaker - he acknowledged that switching off at/near the socket was no longer possible, and was relying on the switch/isolator 'on the machine' for that purpose.

Kind Regards, John

Right, yes I see that now.

Agreed.

 

[bhm1712]

That is true, but is no more true of isolation by means of a plug/socket than is the case with any method of isolation.

Kind Regards, John

Absolutely

 

[stillp]

unless a plug lockout is used with the key to the lock being under the control of the owner of the job in hand

That's good practice, but not always necessary, as long as the person working on the machine has control of the plug at all times.

 

[JohnW2]

That's good practice, but not always necessary, as long as the person working on the machine has control of the plug at all times.

True. In the case of a domestic item of equipment with a BS1363 plug (after all, this is a DIY forum!), removing the fuse whilst the equipment is being worked on would provide an additional level of security - but I doubt that (m)any people actually do that!

Kind Regards, John

 

[bhm1712]

That's good practice, but not always necessary, as long as the person working on the machine has control of the plug at all times.

sorry I disagree. There's simply no way NOT using a lockout would ever be accepted whether or not the person in charge of the job could argue that he kept control of the plug at all times.

 

[bhm1712]

Unless of course he takes the plug off and keeps it in his pocket!

 

[JohnW2]

Unless of course he takes the plug off and keeps it in his pocket!

I'm surprised that you're not concerned that someone could creep up behind him whilst he was working and put a different plug onto the lead

Kind Regards, John

 

[EFLImpudence]

Oh bugger I'll post it anyway.

Better to leave the plug on and keeps it in his pocket.

Otherwise, someone could easily fit another plug on the flex and plug it back in.

 

[bhm1712]

I'm surprised that you're not concerned that someone could creep up behind him whilst he was working and put a different plug onto the lead

Kind Regards, John

Well that would certainly be possible at some of the places I've worked

 

[bhm1712]

Joking aside though, the HsE clearly define what they consider as acceptable in terms of isolation and the "no lockout" option isn't one of them under any circumstance.

 

[stillp]

Joking aside though, the HsE clearly define what they consider as acceptable in terms of isolation and the "no lockout" option isn't one of them under any circumstance.

Where did you find that? I'd agree with you but IME the HSE don't always require that.

 

[bhm1712]

Where did you find that? I'd agree with you but IME the HSE don't always require that.

It's In my safe isolation handbook written by the HSE and also in their own online archive :

Isolation and permits to work
Isolation
The basic rules, are that there should be isolation from the power source (usually, but not exclusively, electrical energy), the isolator should be locked in position (for example by a padlock), and a sign should be used to indicate that maintenance work is in progress.

 

[JohnW2]

Joking aside though, the HsE clearly define what they consider as acceptable in terms of isolation and the "no lockout" option isn't one of them under any circumstance.

I have to take your word for that, and I could well believe that they might take that view in relation to industrial machinery etc. , but how far are you suggesting that has to be taken - what if one is 'working on' a hairdryer, toaster, domestic cooker or TV etc. etc. ?!! I think most people, probably even the HSE, would be happy if it was simply 'not plugged in' whilst it was being worked on, wouldn't they?

Kind Regards, John