I don't think you could get that to work practically. There is almost no power in the panels in the early morning, in fact, just enough to blow up your SCC, in accordance with Murphy's law. So you'd need something else to actually heat your water. I don't think you want a relay switching either AC or panels to the element; I can't think how you'd make that vaguely safe.Northland wrote: righto. That's open circuit. So why not just close the circuit? A resistor or capacitor to draw the voltage down, then drop it out of the circuit once the SCC kicks in? Now where can we find a big fat resistor rated for 120v and thousands of watts? 2 birds - one stone eh?
Besides, if the early morning panels put out over 145 V, even a 24 ohm (2400 W) element will attempt to draw over 6 amps (around 900 W), which the panels won't be able to supply at that time of day, so the voltage will collapse. It may well collapse too low for the PIP to use at all. You also have the problem of chasing your own tail; with the load on the voltage is too low, with the load off the voltage is too high, so the relay chatters until its contacts burn up. Plus, it would have to be a DC rated relay or contactor, which aren't very cheap.