So I tried a gfci tester device on a non-gfci outlet without thinking too much over it. Why, you ask? Well, I guess because I am an idiot. As I pressed the test button, half the house lost power. The breaker tripped, but when I put the breaker back to the "on" position, there is still no power. What did I do?
My understanding was that pressing the gfci test button when the device is plugged into a non-gfci would be a non-event, since very little current would actually flow. And yet, here we are.
Best Answer
Correlation is not causality.
Your understanding is correct, and the power loss was due to something else entirely.
My money's on "It tripped a GFCI that you don't know about".
I bet it tripped the breaker because it's a GFCI breaker (those have Test buttons)... And I have a feeling it's in a subpanel, which is fed from another GFCI breaker. So now you need to hunt that down.