We recently bought a 1950's house that had an addition done in 2004. At that time the electrical service was relocated and upgraded to 200A. It seems as if the old main pannel located in the attached garage was converted to a subpannel fed off a 100A breaker in the main pannel. There was also another subpannel in the garage for the air handler fed off a 60A breaker in the main pannel. When we moved in an electrician added 2 new circuits for the kitchen. He added them to the air handler subpannel becuase access to the attic to get to the main pannel would have been very difficult. I then added one more circuit to that pannel for a garage receptacle and 2 exterior lights. From my reading, it seems as if subpannels in attached garages should have neutrals and grounds separated and be fed by a 4 wire feed from the main pannel. In my pannel there is only a 3 wire feed and the grounds and neutral share the same bar. I could move these circuits to the main pannel, but the access to the attic is terrible, although I will probably have to do that eventually. My question is- Is this a dangerous situation and why?
Thanks for your advice,
Air handler sub pannel with kitchen and garage circuits:
Old main, now sub pannel for old part of house, dryer, water heater, range.