This is how I did it, a long time ago. The product was essentially all primary wiring with many relays CB's and triac controlled circuits.
The thing was energized through a 1:1 isolating transformer and the hipot voltage was applied between a center tap of the isolating transformer secondary and the grounding means, while the product ran through all possible functions. That is the basic idea; there were several considerations: 1) The hipot detector must ignore the reactive current flowing through the isolation transformer. 2) There must be a scheme that allows the operator to run the product safely during the test. 3) I had to have the transformer specially made with creepage distances suitable for the hipot voltage. I am sure there were other concerns. It has been a long time. However, it did work. Due to functional testing we were satisfied that there were no across the line shorts prior to the hipot test. Lou Aiken 27109 Palmetto Drive Orange Beach, AL 36561 USA Tel ++1 251 981 6786 Fax ++1 251 981 3054 Cell ++1 251 979 4648 ----- Original Message ----- From: [email protected] To: EMC/Safety List Server Sent: Tuesday, May 14, 2002 22:19 Subject: Hypot Testing Question I have some products which fall under UL61010A-1 and have several relays and contactors in the primary circuits. During the hypot test it is my understanding that all relays and contactors in primary need to be in the "on" state to allow the test voltage to fully circulate within the primary circuit, thereby allowing a valid hypot test. It is taking a good deal of time to properly set the unit up to do the test, and then remove all of the jumpers before the unit ships. Does anyone have any ideas, recommendations or suggestions on ways to speed the process? Some units may have upwards of 7 contactors and relays. I am also looking for some way to combine the hypot test with a shorts test to verify that there are no shorts due to wiring errors from line to line (single and three phase products). Again, any suggestions or recommendations are welcome. Thanks in advance, Steve Brody [email protected] ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
