[velcro]

It basically has to do with Harmonics. Years ago most all power from the grid supplied to the public was in the 3 rd Harmonics & appliances, electrical equipment is: panels ckt. breakers, xformers ,computers had no problem with handling electricity coming from the power company's in the 3rd Harmonic. Now all power supplied off the grid is in the 5th Harmonic and many times the equipment it is supplying can not handle the 5th Harmonic wave length. This difference in the cine wave is what is probably causing these older breakers to trip.