Here's an interesting question that came up during a standards committee meeting. I'll base the question on EN60950-1 although this approach and the question it raises are universal.
Fault testing is required in section 5.3 and compliance criteria includes hipot testing according to 5.3.8 which sends me to 5.2.2 which sends me to Table 5B to look up the test voltage to be used, based on the type of insulation involved. In other words, the normal hipot test applies. BUT...we've just done a fault test. So why are we required to (for example) test Reinforced insulation at the level required for Reinforced insulation when all that is required elsewhere in the standard is that after a single fault we are left with at least Basic insulation? This line of thinking says the hipot test following fault testing would only be required across Reinforced insulation and would be done at the level for Basic insulation. No hipot test is required on Basic insulation after the fault, but the protective earthing must still be intact (assuming earthing was the 2nd level of protection that allowed the design to use Basic in those locations). Comments? Arguments for or against? Thanks, Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are those of my invisible friend who doesn't like being hipotted regardless of the level. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
