The answer to 'panel upgrade sparking' is that sparking during a panel upgrade is a serious issue that requires immediate attention from a licensed electrician. Sparking can indicate a short circuit, faulty wiring, or other dangerous electrical problems that pose a fire hazard. Trying to troubleshoot or repair the issue yourself is not recommended, as it can be extremely hazardous.
Some common causes of sparking during a panel upgrade include loose connections, outdated or damaged electrical components, overloaded circuits, or incorrect installation. Symptoms may include flickering lights, buzzing noises, or visible arcing. The only safe solution is to have a professional electrician inspect the panel, identify the root cause, and make the necessary repairs or upgrades to ensure the system is functioning safely.