Help needed for large crane overload warning

Yeah the kids are getting to an age now where they're getting interested in this kinda thing. My oldest is 12 and he helps out every now and then. Nothing dangerous, they know not to come into the back field where all the fun stuff happens. The inverter is under lock and key so I couldn't see it getting activated without me securing the area first, but still, is it a bad thing to have a beacon just in case?