I have a client who has a secondary pwb that has traces and vias that may have 
100 vdc on them adjacent to ground. 

Per 61010-1 there is a requirement for spacing and/or dielectric test, both 
depending on what the mains voltage is. 

The question is why is the mains voltage a consideration or concern if the 
100vdc secondary voltage is several layers of impedance and circuitry from the 

Is it a concern that a surge on the mains would trickle down to the secondary 
circuit, or is there another reason/rationale? 

I suggested that a dielectric test per Table 6 [in A1] would suffice and put 
the issue to rest for this product, but the question from the designers remains 
as to why is it a concern in the standard of what the mains voltage is.

Is there anything in the standard, that I haven't found, that does not require 
Table 6 to be followed if there is no way for a mains surge to impact the 
secondary voltage? 

I look to the experts for an explanation. 


Steve Brody
sgbr...@comcast.net mailto:sgbr...@comcast.net
C - 603 617 9116

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 

All emc-pstc postings are archived and searchable on the web at:

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>
To unsubscribe from the EMC-PSTC list, click the following link: 

Reply via email to