On Sat, 20 Oct 2018 at 05:25, Martin McCormick wrote: > RussellMc writes: > > Be absolutely certain that the contacts are rated to handle the maximum > AC > > voltage that will be encountered. > > > > The AC load spec is almost always far more stringent than the DC load > spec > > and failure to note this can cause relay failure at well below apparent > > rated (DC) value. > > > > > > > > Russell > > Now, I am curious. Why would the AC load spec be more > stringent? Now I am curious! Why did I write that ? :-) :-(. I have transposed AC and DC and cannot imagine why I did so or why I did not notice !!! Sent at 19:18 according to header (NZT?) so I cannot excuse by lateness of night. Doh! Yes, to all the rest, sort of. With a capacitor it is intuitively 'obvious' that maximum AC voltage point is the worst for closing a contact. With an inductor "this is not the case". I am not going to risk a one sentence explanation here :-) - rushing off to do "stuff" - so others may wish to comment on the joys of closing and opening switches in AC loads. Russell --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .