Doug: At least in Spain, public switching telephonic network works with 48 V dc but the ringing signal could reach 75 V ac (hazardous voltage according to LVD). In fact, if you catch both poles of a telephone line during the ringing process, you will suffer that voltage. So for that reason, LVD applies.
---------- De: Doug McKean[SMTP:[email protected]] Enviado: lunes 10 de febrero de 1997 21:05 Para: Juan Pedro Peña Cc: [email protected]; [email protected] Asunto: Re: BS EN 41003: 1997 now available I'll throw in two cents worth. We have been having a discussion concerning where standards do and do not fit in to particular pieces of equipment. I have had discussions in the past with people about 48VDC TTE products and the LV Directive - 73/23/EEC. The LVD specifically states in Article 1 "For purposes of this Directive 'electrical equipment' means any equipment designed for use with a voltage rating of between 50 and 1000V for alternating current and between 75 and 1500V for direct current, other htan the equipment and phenomena listed in Annex II." Annex II goes on to list "EQUIPMENT AND PHENOMENA OUTSIDE THE SCOPE OF THE DIRECTIVE Electrical equipment for use in an explosive atmosphere Electrical equipment for radiology and medical purposes Electrical parts for goods and passenger lifts Electricity meters Plugs and socket outlets for domestic use Electric fence controllers Radio-electrical interference" Now, even when TTEs operating at 48vdc allow for a Bellcore lower/nom/upper limit of 42.4/48/56.5 tolerance, those dc TTEs are not covered by the lower 75vdc limit of the LVD. So that 115/230 VAC TTEs were included, but the 48VDC versions of the same model weren't. Comments? I'd really like to know how wrong I am. This was the basis of one of those really terrible debates I had with a former boss where I wrote him up in a memo to his boss.
