RCD protection in an IT run office

Oh dear, your quote in your previous post relates to the IT earthing system, not information tech. Can't imagine what the protective conductor currents will sum up to, I'm with JP here i'm afraid.

It’s a TN-C system. My understanding was that this system with a PEN earthed in more than one place ( for example the distribution side of a PME or MEN  installation) then PEN and live currents are always out of balance, so any RCD will operate, even if there is no fault? Please correct me if I am wrong. Always willing to learn!

So there are no CPCs anywhere at the property, since the earth and neutral are combined at each socket outlet?

I hope that this system is not TN-C in which earth and neutral are combined up to the point of use.

More likely to be TN-S with neutral and earth seperate throughout, or TN C S whereby the neutral and earth are combined in the DNO network but separete in the consumers installation.

Hahaaaa! My bad, I’ve re-read the 61008 chapter article referring to IT systems and believed it to be (Info Tech related) instead of the type of system for which it refers. I humbly bow down before you all. In my defence, it’s been a long week! 

This was because I was researching RCD’s and risk assessing them in an IT environment, meaning computers and not the earthing arrangements! I’ll hold my hand up?


In all honesty, the reason for me questioning this, was because it it were me installing, I would have used RCD’s. My thoughts were that of perhaps back then in the mid 90’s when it was installed, RCD’s were not aware used. 

the system I have is all steel trunking and conduit so to eliminate the need for it??! Maybe, I dunno? You live you learn!

Joe


Again you clearly do not know the difference between an IT system and IT equipment used in an office!


The problem is you do not know you are not competent to carry out inspection and testing and are probably breaching Regulation 16 of the Electricity at Work Regulations 1989.


You are also clueless about the installation being a TN-C earthing system!

I agree John, he has read the wrong document too, reading 61008 tells you nothing about installations, that is BS7671 territory as we all know. This seems to me to be a clueless unqualified chump of the first order, and that is not at all rude!


For I&T you need at least C&G 18th edition, 2391/ 2394&95 and MANY years of experience. You can be prosecuted under the EAWR if you are not competent and qualified. Buyer beware....

I think rather than make this a personal attack, be gentleman and point me in the right direction instead of wasting people’s time with your belittling comments. I am a fully qualified electrician and have been for a number of years. Shock horror! If you read through my last post where I practically called myself a muppet, there’s no need for you to jump on that wagon. We learn every day, we make mistakes and we deal with them the best way we can. Rather than send me a negative comment, turn it around and offer good, decent advice, change your attitude, jump down from your high horses and help others out! We are all in this trade together, and if we can all chip in, be respectful on these forums, we can all help those in need of guidance. Come on guys...!

Whilst I agree that personal attacks should be avoided, it does seem that the O/P does not yet have sufficient knowledge and experience to carry out this sort of work.


Inspection and testing requires very considerable experience, arguably more so than new installation work.


I have seen a regretable number of inspection reports that contain serious factual errors, in particular the condemming of even slightly unusual circuits that are safe and permitted.