We are planning on using UL Recognized / CSA Certified disk type varistors from line and neutral to ground, in a product headed for CSA and CSA/NRTL approvals. We are short on space (who isn't?) and the designer raised a question that I wasn't sure of the answer to.
Q: Is the insulating coating on the disk considered sufficient and reliable, so that creepage and clearance from the disk to chassis or other live parts can be ignored (except where the bare leads emerge from the insulating coating)? My initial response was no, treat the whole body of the part as a bare live part at line voltage, which is the conservative answer, but I'm not so sure it's right. I know of a European ruling that says the body of approved X and Y cap's can be considered to be Basic insulation, so maybe there's a similar stance on MOV's. Can anybody shed any light on just what the approval of these things covers, and has anybody had a ruling from UL or CSA on this question? Thanks in advance for your help. Regards, Jim Eichner Statpower Technologies Corporation [email protected] http://www.statpower.com Any opinions expressed are those of my invisible friend, who really exists. Honest. --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
