PME final circuits question

[deegee]

I have a query,

Im working on some signage that is connected to a PME supply. This is supplied to a leb header by straight concentric 16mm cable and then to and RCD with outgoing circuits to the sign.

Now I have just seen that work by others have been carried out in the form of doubling up on the load side of the rcd for a socket and the loadside has been connected as pme (neutral and earth together ) and even at the electronic ballast, now Im pretty sure this is a NO as PME connection of this type is only allowed at source. (ie the head with the hfc fuse) Now am I right in understanding that the RCD will not have an imbalance to work from and therefore dangerous apart from the fact of bad practice.


head = 16a hrc
rcd = 10a
Please advise Kind Regards DEE

 

[rattlehead85]

N&E as a concentric on the load side of an RCD ?. How the hell does that even stay on.?You have created an imbalance straight away!. How can the RCD stay on if the returned load flows down both the neutral and the earth!!

 

[deegee]

It all started when I was asked to check the site due to it keep tripping, advised the client of way it was connected and that was the cause and that the problem lies there. Apparently there are loads more scattered abt like this and I stated these need rectifying urgently and not had a thing back.

 

[rattlehead85]

Ignore that first post. Interpreted it wrongly. Still what you describe is classed as a TN-C system (PEN conductor)which is prohibited on a consumers installation as set out by the ESQC regs 2002. Your RCD is rendered useless and all your exposed conductive parts are connected to this PEN conductor. A no no all day long. C1 departure on an EICR and a shut off and make safe essential action.

 

[deegee]

Thanks mate,
Thats the confirmation I was looking for. I did state that there is no reason for it to be connected like that, not even a lazy shortcut would any electrician who knows there stuff or any qualified spark for that matter carry out work in that manner. I believe its been done by someone not having a clue and on advice from someone who thinks they know. Maybe why I havent heard anything back. couldn't believe my eyes. Took photos and emailed a snotty report. PME N/E is only to the cutout HRC fuse.

 

[Engineer54]

Thanks mate,
Thats the confirmation I was looking for. I did state that there is no reason for it to be connected like that, not even a lazy shortcut would any electrician who knows there stuff or any qualified spark for that matter carry out work in that manner. I believe its been done by someone not having a clue and on advice from someone who thinks they know. Maybe why I havent heard anything back. couldn't believe my eyes. Took photos and emailed a snotty report. PME N/E is only to the cutout HRC fuse.

Think along the lines of Eastern European, and you won't be too far from the truth!! lol!!
Common practice in many of these rural Eastern European countries... lol!!

 

[Clive P]

Hi,
Engineer 54 , you beat me to it,

Regards.

 

[netblindpaul]

Is it public sector signage supplied from the public street lighting supplies?

 

[Knobhead]

On a RCD?