Opto-Isolated, "0" voltage turn-on, internal snubber
Just a followup. This SSR showed up. It's a Kodak, PN 611490. I have duly searched for a datasheet and come up empty. The input resistance is about 891 ohms, so that's good news. But what I hadn't thought about was whether I need a big heat sink for the load. From the faceplate of my A/C unit, the load will be ~ 8A @230VAC. The MPJA page for it says,QuoteOpto-Isolated, "0" voltage turn-on, internal snubberwhich tells me not much.So, anyone have some experience or memory to draw on here?@JimG. It's going to be inside an enclosure, but your point is well taken.
As far as heatsink needed, yes you will. The maximum current ratings for SSR only apply if you can also keep the device below it's maximum operating temperature rating. Past experience I've has is that most SSR will 'drop' about 2vac across it's switching device, so at your 8 amp current load, that's 16 watts of heat dissipation that will surely overheat the SSR unless bolted down to a large enough heatsink using proper heatsink paste, etc.So how big a heatsink? Probably larger then you wish, have room for, or have avalible on hand.
I have been using similar units (that I bought used at a hamfest) to control my baseboard heaters for several decades. The only heatsink is the 4" x 4" aluminum plate that I fabricated to mount them on and to cover the standard outlet box that they are mounted in. Don
That's an idea too. But, what would Tim Taylor do?
QuoteThat's an idea too. But, what would Tim Taylor do?I guess I am culturally deprived.Don