The problem is also in new installations, even restaurants. Within days of completing a restaurant last year, I was getting calls about the GFCI breakers tripping. All the equipment was new and good quality. I did check the drink mixers, coffee machines, compressors and other equipment for resistance to ground with a 120 volt D.C. megger test. All of it seemed to be OK. I tested all of the 40 different circuits with an Ideal Sure Test and they all tested exactly the same. The breakers tripped in about 6 milliseconds at about 5 milliamps, as I recall. I did check some of the wiring with a megger as well, no problem. I also checked some of the neutrals to be sure that they were not crossed. I also checked for shorts between the neutrals and grounds. The breakers (bolt-on Siemens) seemed to be well made and were in four different panelboards. The wiring was thhn in conduit, both emt and pvc.
After spending a day there, I had no answer other than inductive and capacitive type loads on GFCI breakers are maybe not compatible. I have had this problem at other restaurants that I have wired over the years.
One of the results of this type of problem as some of you have alluded to is that customers then come to not trust either the work of the electrician or the equipment they install and seek to bypass the protective features by installing different devices just so they can have reliable power for either homes or businesses. They do not know who to believe when they are told that we cannot fix their problem without violating the code. What the heck do we do?
