> So, did ETL make a mistake in specifying a hipot test? Or am I missing > something in the UL-61010 requirements? Possibly. OR, possibly, the requirement is there to see if the device explodes/outgasses something toxic/bursts in to an unquenchable flame. If you're doing safety testing, which is usually the primary concern of UL testing, the tests are more often about making sure the device fails gracefully than making sure it doesn't fail. You should DEFINITELY ask them both whether the test is truly needed AND what the point of the test is. If the person you ask doesn't know, push the matter- someone has to, or you're just being asked to destroy one of your (expensive?) devices for no good reason. Mike H. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist