rcbo neutral lead question

[Super.sparks]

Hi,
1st post so go easy on me lol. just wondering if this is normal or if i should be looking for an issue?

Today i was fitting ferrules to the fly leads on a compleated cu,cu was fitted 2 weeks ago but did not have any ferrules at the time.

So upon dissconnecting each each lead (main switch still on but rcbo off but some other rcbos still on) ,i had 210 volts to earth on the fly lead when removed from the neutral bar, same on the next one as well.

THANKS IN ADVANCE

 

[pc1966]

Some RCBO are powered from the bus-bar side, not the load side, so even when they are "off" the internal electronics is still powered, hence the voltage appearing on the neutrals when you pulled them.

I know for sure the Wylex DP ones are as fitted some recently and you see an IR test fail on the busbar due to this, but the advantage is you can IR test the final circuits simply by flipping the RCBOs off!

 

[snowhead]

There was a long thread on here on this a while ago.
I believe all newer RCBO are powered from the Bus bar Live side, probably so there is no delay in them working in the first millisecond that they are switched on.
I would imagine like everything else the electronics are far more complex than they used to be.

Manufacturers don't appear to be concerned enough about the issue to put a warning on the front of the RCBO, just a drawing on the side, obscured by the adjacent RCBO /MCB showing the connection.
They'll argue no-one should be working on an RCBO with power still on the Busbar.

 

[Darkwood]

In reflection of the advice above this also this puts a spot light on the reasons boards should be safely isolated, the monitoring electronics are permanently live on many brands even when the RCBO is off so removing the N fly lead means you are breaking a live circuit and been exposed to the inherent risks that come with that, equally one needs to ensure isolation before fitting RCBO's for the very same reason, although safe isolation practices would mean you never are in that situation, right!

 

[Super.sparks]

In reflection of the advice above this also this puts a spot light on the reasons boards should be safely isolated, the monitoring electronics are permanently live on many brands even when the RCBO is off so removing the N fly lead means you are breaking a live circuit and been exposed to the inherent risks that come with that, equally one needs to ensure isolation before fitting RCBO's for the very same reason, although safe isolation practices would mean you never are in that situation, right!

i knew someone would point out safe isolation, dont worry i know all about it,44 years in the trade and still here. just wasnt sure if this was normal as i never knew that newer rcbos were powered from the busbar,hence the question.

 

[Darkwood]

i knew someone would point out safe isolation, dont worry i know all about it,44 years in the trade and still here. just wasnt sure if this was normal as i never knew that newer rcbos were powered from the busbar,hence the question.

We have to be seen pushing the right message and all, 30yrs myself and counting and don't get me wrong, I know what happens on site is not the same as happens in an AM2 exam, common sense and experience is key, I work live all the time but need to for my line of work, you simply cannot shut production down for a task that can be safely done live, it would cost the economy millions to follow that rule to a T and apply it to all cases.

 

[Megawatt]

We have to be seen pushing the right message and all, 30yrs myself and counting and don't get me wrong, I know what happens on site is not the same as happens in an AM2 exam, common sense and experience is key, I work live all the time but need to for my line of work, you simply cannot shut production down for a task that can be safely done live, it would cost the economy millions to follow that rule to a T and apply it to all cases.

I’m like above but if it had to be done live I would do it myself not one of the guys working for me doing it. I don’t want to be the one that has to call their moms or wife and tell them that their loved one is not coming home today because I didn’t do my job and let them work it live and got killed

 

[Zerax]

I’m like above but if it had to be done live I would do it myself not one of the guys working for me doing it. I don’t want to be the one that has to call their moms parent/legal guardian or wife partner and tell them that their loved one is not coming home today because I didn’t do my job and let them work it live and got killed

Just corrected that for you Mega... to bring it inline with the PC policy this side of the pond.

 

[Darkwood]

Just corrected that for you Mega... to bring it inline with the PC policy this side of the pond.

I think he was referring only to his own staff as expressed and with that in mind his terminology I assume is accurate to describe his staffs next of kin given he probably has the insight of knowing them be it personally or through general conversation.

PS - What PC policy is this you speak of

 

[pc1966]

I think he was referring only to his own staff as expressed and with that in mind his terminology I assume is accurate to describe his staffs next of kin given he probably has the insight of knowing them be it personally or through general conversation.

PS - What PC policy is this you speak of

For those unable or unwilling to splash out on an Apple, I believe.

 

[MJPD29]

I've had this with wylex and crabtree. I find in incredible t ha manufacturers are allowed to do this or even don't put in a warning label to fit. Just another example of the drop in quality of well known brands.