That's a very easy question... MOVs are cheap and reasonably effective at both protecting primary circuits and preventing transmission of spikes and spurious signals into secondary circuits where they wreak functional havoc.
Few consumers would pay for industrially robust goods. T ----- Original Message ----- From: Richard Nute Sent: 12/15/12 07:08 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] Why use an MOV? Presumably, the MOVs in question are connected line to neutral. I would expect the designer would design his primary circuit to withstand the normally-expected 1500 V transient. Why use an MOV??? Best wishes for the holiday season, Rich - ---------------------------------------------------------------- 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 < emc-p...@ieee.org > All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 < emcp...@radiusnorth.net > Mike Cantwell < mcantw...@ieee.org > For policy questions, send mail to: Jim Bacher < j.bac...@ieee.org > David Heald < dhe...@gmail.com > - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ 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 <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>