Strange phenomenon happening to me - electric.

[Robert Engel]

Is the 40A sub-panel breaker located in your main house panel or somewhere else?

House and shop are separate services. Sub panel is off the shop service.

Was there anything out of the ordinary preceding the 40A breaker tripping? Electrical storm, high winds, heavy rains...?

yes a quite violent storm.

When you reset the 40A breaker, was it a solid click or did it feel a little sloppy or weak?

Feels solid.

You can do some tests with your voltmeter that would help. Test the voltage before the 40A breaker. If it's in the house panel, remove the cover and put the test leads across the main lugs. Then check the voltage on the load side of the breaker (the lugs on the breaker). Then test the voltage where it enters the shop. If you see any unusual voltage drop, more than a couple of volts or so, you may have a bad breaker (if the drop is at the lugs of the breaker) or bad connection somewhere or open insulation underground that's bleeding to ground.

It could very well be there was a spike and that breaker picked it up. I once had a 2000A, 480V disconnect fail to trip and it went through every current protection device upstream until it finally tripped a 112kV transformer and shut the whole site down. There were some very angry people that day.

Anyway, if you can't find anything unusual, you'll have to wait and see if it happens again. It may not.

Thx. I really think it was a fluke but I will do those tests.

My gut keeps telling me it’s got something to do with taking those trees down, but my brain says “coincidence”.

[Julie Moriarty]

Based on what I know now, I'd say that breaker tripping had more to do with the storm than with any internal problems. Stray currents are unpredictable. Electrical storms can send induced currents into power systems that can reek havoc. That may be all that's to your tripped breaker.

[Robert Engel]

Update: the plan is to run fiberoptic cable.

[Chris Fairbanks]

Robert, that’s a good call. I suspect it will save you money in the mid term as I suspect the replacement modem cost is not cheap. If you need any help picking out parts feel free to hit me up.