On 02/02/2016 06:14 PM, Gene Heskett wrote: > It basically consists of two SSR's in series, the first one being > the main switch that enables AC power to reach the transformer by > way of a 51 Ohm 200 watt inrush limiting resistor. And that after > the filters are charged, nominally 10 seconds, a second SSR is > fired to short that resistor, allowing the supply to make full > output. Controlled by a couple timers driven by the > motion.machine_is_on signal. > > Hmmm, maybe this is the problem. Maybe, due to the way the zero-crossing circuits work, putting two SSRs in series totally fouls up the internal logic. it seems you could put the two relays in parallel, one with the resistor in series with that relay. So, you turn on the relays exactly as before. the one with the series resistor first, then the one with no resistor. My GUESS, and it IS a guess, is that somehow, with the two relays in series, and that they have zero voltage switching logic in them, that they fool each other and end up passing only half-wave power to the transformer. Does the transformer clunk right when this breaker-tripping event occurs? If the transformer is fed half-wave power, the core will saturate in barely more than one line cycle, and a tripped breaker seems quite likely. Zero-crossing SSRs are really NOT good for transformers, anyway, as they just about guarantee a saturated start for the transformer, anyway. What you REALLY want is a relay that always closes on the voltage peak, but they don't make those.
Anyway, it seems my idea would require only moving a couple wires, so you might try it. Jon ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
