Pauluk and Djk,
I don't think UL or manufacturers would want the UL mark to be valid in Europe, since it would make American manufacturers liable in Europe without ever having intended to sell the product there! Then you'd have to put up some other barrier to trade instead.
In the cases where the EN and UL standards are the same, if UL has tested it the manufacturer can safely apply the CE mark too. (If the voltage match and there is no non-electrical requirement.) So far the only standard that I know has been harmonised is EN/UL 60950, Computers and similar stuff (No, that's not the official name
![[Linked Image]](https://www.electrical-contractor.net/ubb/smile.gif)
) But they are working on it. (IEC 947 is transferred in some form too, which is why you can find UL listed breakers of this type.)
Back on topic:
Elect,
The only outstanding issue I have is regarding the RCD.
Is this something that is typically required at the main power distribution for the plant or is it necessary to provide this on each piece of equipment that is connect to the IT system?
The purpose of an RCD in a IT system is to prevent high-impedance faults between systems with separate earth (ground) systems.
As you already know, the transformer is ungrounded. Instead the earth conductors from the equipment are connected to each other and possibly to an earth rod. Thereby a double fault on different phases (or phase-neutral) will trip the breaker(s) by short-circuiting via the earth conductor.
This wouldn't require an RCD. However, in a system serving several buildings each building may have its own earthing system. This means that an earth fault in building A and a fault in building B will not trip the breaker. But there can still be high impedance paths where the current can flow. This is where the RCD comes in. In case of a fault between the earthing systems, the RCD will trip before the current between them is high enough to be a danger.
Therefore, it would seem sufficient to provide one for each earthing system. But I'm not familiar with French regulations!
I guess I have the same issue with the PIM. Not sure where to find this info.
PIM is a term I'm not familiar with.
I will quote DJK since he got a very good point:
If I were you I would contact an electrical contractor in France who deals with industrial installations.
You should really get the equipment inspected and if possible signed off by a local expert to remove any legal risk!
This will save you trouble, risk and most likely money. In fact, you probably can't do it without local assistance.
Have a look at
www.ieconsult.fr The have a number of technical papers online. If the answers aren't there, you can hire them to help you.
Remember, free advice on the Internet is worth what you pay for it.
[This message has been edited by C-H (edited 08-17-2003).]
