I have a tool with 3 GFI, Main 200A and an 80A followed by a noise filter, cable, and another 80A GFI. The 3rd GFI is fine, no trips. The 2nd GFI, 80A has intermittantly triped several times, even with tool idle. The 3 GFI's are supplied with 120vac for operation. If the 3rd GFI never trips, then we are assuming the noise filter is causing the 2nd GFI to trip. Can you give us some help of what we are looking at, and is our noise filter the most likely culprit?
Dave
Dave