For what it is worth, My personal rationale on applying LVD, EN 60 950 and EN 41 003, etc is:
The operating voltage limits as defined in the LVD have been well documented in recent responses. TTE intended to be connected to analogue PSTN lines in particular would fall under this scope due to the levels of ringing signal, etc. You could debate whether ringing signal was actually powering the unit but it is an external voltage source. Equipment for connection to other types of telecommunication service could be argued as not having the "hazard" of ringing signal and this certainly applies to types of digital interfaces. However, what we cannot ignore is the fact that many (most) terminal equipment also has a primary mains power supply source or is designed to be used inside a host (or in conjunction with a host) which uses a primary mains power source. If the TTE itself has a primary power source, then obviously the LVD applies and EN 60 950 would be the standard to use. If the TTE is intended for use inside a host then again it must be designed not to compromise the integrity of that host. So again the LVD applies to the TTE as a sub-assembly and again EN 60 950 can be applied. The only thing to keep in mind when using the standards is the expected safety status of the interconnection points with the host apparatus and build the safety strategy for the TTE around this. EN 60 950 defines Telecommunication Network Voltages (TNV) and provides requirements for the isolation of circuits at TNV from other circuits including SELV and Protective Earth connections. In my opinion EN 41 003 is almost redundant and EN 60 950 shoud be used wherever possible. EN 41 003 still has an application, I think (I may be wrong) in covering equipment which is solely powered by the telecommunication network (analogue connection points), eg simple telephones, etc. Nick Genesys ---------- From: [email protected] on behalf of Doug McKean Sent: 11 February 1997 20:03 To: [email protected] Subject: Re: BS EN 41003: 1997 now available? Ian Chapman wrote: > > A Notified body should figure out what is required and what is > not required not your boss. Under the TTE directive TTE > equipment must be approved by a Notified Body to be marketed in > the EU, if I understand the rules that is. If you were unable > to find a Notified Body to agree with your safety assessment you > would have a delay in your product. > > Regards Ian. Incorrect. We are NOT discussing TTEs in reference to the TTED - 91/263/EEC. We are discussing TTEs in reference to the LVD - 73/23/EEC as I have specifically stated several times. ************************************************************ ------------------------------------------------------------ The comments and opinions stated herein are mine alone, and do not reflect those of my employer. ------------------------------------------------------------ ************************************************************
