It depends. We built and deployed some IoT devices (controlling and reporting status of lights, HVAC systems, that sort of thing) to a bunch of greenhouses--one

It depends. We built and deployed some IoT devices (controlling and reporting status of lights, HVAC systems, that sort of thing) to a bunch of greenhouses--one of which ran on generator power. The customer was running the generators right at the maximum capacity, and we'd see really, really odd things on the power lines. Some times a surge like you mention, sometimes changes to the frequency, sometimes changes to the voltage. We discovered all sorts of weird brownout conditions in our devices.