So if it's a solid state relay, there's probably a silicon controlled rectifier or triac and no actual relay coil? The control voltage probably goes through a resistor to the gate of an SCR.
I'm no expert, but I'm guessing they're fine, especially if it's been working all this time. They may even have checked with the component manufacturer and verified it will work with the higher voltage. The 30VDC spec might just be a UL thing. Perhaps it's like 1N400x series rectifier diodes. Do we really think they manufacture or test them differently to get 50, 100, 200, 400 volt ratings? They're probably all the same diodes just with different markings. If I were designing something for mass production, I wouldn't do it. I've certainly seen problems caused by designs that worked but the components specs were inadequate. Like a manufacturer does a die shrink on a logic chip and it gets faster and now there's a race condition. Or a different manufacturer with an equivalent part gets substituted and now 48VDC is too much. From: AF <[email protected]> On Behalf Of Adam Moffett Sent: Thursday, June 5, 2025 7:59 AM To: 'AnimalFarm Microwave Users Group' <[email protected]> Subject: [AFMUG] SSR control circuit over voltage I was looking at pictures of someone else's enclosure (a camera company). They have a router powered through a NO solid state relay and they're keeping the coil circuit energized continuously. The specs on the relay say the control voltage is 10-30VDC, but these folks have a 48V power supply. I'm not sure how long it's been in service (finding out today), but I'm wondering if this is a time bomb. Is that relay going to fail? What's the likely mode of failure? One article I saw while googling suggested the relay might get stuck on..not the worst thing, but it would defeat the purpose if that's what happens. -Adam Get Outlook for iOS <https://aka.ms/o0ukef>
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