Doug,

What you are missing is that the directives specify standards that apply 
to your equipment. We have to base our answer on the standard, which in 
this case sounds like ITE (950). 

Regardless of the input voltage, we still must consider the following:

* How is the equipment isolated from the TNV? 950 para. 6 describes the 
requirements.

* Could there be a component fault that would cause an unsafe condition 
or shock hazard?

* What about component overheating? Are all components rated for the 
minimum temperature / voltage that they will see in normal and abnormal 
use?

I can tell you that all of my customers require certification for 
products operating at a nominal 48 VDC. I also certify products that 
operate from 5VDC......just look at your computer mouse and keyboard.

Hope this helps you understand what the standards are about.

Regards,

Edward Eszlari
TUV Rheinland of N.A., Inc.
Marlborough, MA 
508-460-0792

>
>The Low Voltage Directive (73/23/EEC) applies to 
>equipment that operates from supply voltages of 
>50-1000Vac or 75-1500Vdc. 
>
>Does this mean that strictly according to the 
>standard *in and of itself*, that is according 
>to 73/23/EEC by itself, safety testing need NOT 
>be applied to ANY piece of equipment that operates 
>from 48vdc in a Central Office? 
>
>Specifically, say a piece of equipment in the rack 
>that does not touch the E1 line? 
>
>What am I missing here ... 
>
>


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