Hello group, I have two questions:
1. Where can I get ahold of copies of Korean deviations to IEC 950? 2. I have just learned that one deviation is that 45 VDC is the cutoff voltage for SELV. How does this impact the design of centralized dc powered equipment operating at -48 VDC? The way I've figured it, it has the following consequences: - because input voltages are now considered hazardous secondary, the insulation requirements between input and SELV circuits are BASIC, instead of OPERATIONAL as they would be if the line is drawn at the standard 60 VDC. - creepage distances remain the same, but clearances must be determined from the B/S column of Table 3, IEC 950, instead of the Op column as before. - and most importantly, ***clause 5.4.4 will no longer be applicable***. Important because compliance options which were available before no longer are. If either options b) or c) in 5.4.4 were selected as design courses, instead of meeting creepage/clearance, it seems like the Korean deviation renders the design non-compliant. Any thoughts? thanks! Mark ------------------------------------------------------------------ Mark Ortlieb | Product Safety Engr. | QUALCOMM Incorporated QUALCOMM Incorporated | 6455 Lusk Blvd. Tel: 619-658-3208 | San Diego CA 92121, USA Fax: 619-651-1997 | <mailto:[email protected]> | <http://www.qualcomm.com> ------------------------------------------------------------------
