Buddy of mine moved into his new house, and asked me to wire up his new doorbell camera.
I was all like
"Sure, that''ll be super-duper easy!"
So I go over, he hands me the doorbell, and the instructions are...pretty fucking simple. So I rewire the chime, install the doorbell/camera....and nothing.
So now I'm troubleshooting the simplest circuit in his house...and I figure out...that the transformer is dead. But I know that his doorbell worked right before we started, because I pushed his doorbell when I got to his house, LOL. So at some point, while I was putting this thing up, that transformer died.
We go to a local Home Depot, and ask a guy in Electrical where the hell the doorbell transformers are. We don't want a kit, just the transformer. And he asks if this is for a Ring/Wyze/etc.
This kind of throws me (why would he ask that?), but we're like "Yeah...?" and he walks off towards a different aisle, and starts talking about how tons of people have had to buy new transformers for this kind of stuff. He steers us over to some much larger transformers. The new ones here were about 30w or VA (give or take; fuck off RE: power factor) so that is about 3 times the rating on most vanilla doorbell transformers.
At this point it dawns on me that we probably overloaded that transformer. We get back, I install the new transformer, and everything works like a charm. So at this point I'm shocked that 1) the guy at Home Depot was actually helpful, 2) the load rating on the doorbell camera is 10vA, 3) the rating on the old transformer is also 10vA, 4) that this would burn up a transformer as quickly as it did.
I deal with industrial control transformers all of the time, but those are always fused externally. And I can't imagine that we shorted the windings somehow (but primary coil = no continuity). But back in the day when I wired houses for a living, you wouldn't even bother troubleshooting past the shitty-ass 3rd world country transformer...you just tossed the old one and bought a new one.
So on a hunch I took this to work on Monday and opened it up on my bench.
...because OF COURSE it had a 'thermal' fuse inside of the tape on the coils, where you otherwise can't see it. And of course it's shot. But it mildly pisses me off that the manufacturers of the camera didn't put anything in the instructions about their product needing an amount of current that just happens to be the max rating of most cheap doorbell transformers. Meaning that they're either incompetent, or they absolutely 100% knew going in that their product was going to overload a ton of existing transformers upon installation.
I should probably have known better, but I just assumed that the load was small enough not to matter.
What *WAS* hilarious to me, though, was reading through Reddit posts afterwards, when people tried installing their own stuff and then started having to replace transformer after transformer and not knowing
WHY their transformers kept dying.
