I have two fuse boxes, one never trips, on the other the main RCD trips occasionally when all MCB's are on, if I switch two MCB's off on the lighting circuits, or one of the power MCB's the RCD does not trip. It does not seem to care which MCB I switch off on the power circuit, but the RCD does not trip. I originally thought that because I have 9 strip lights in the garage that may cause the problem? But as I can switch any one power circuit off and then the RCD does not trip. Both are Wylex fuse boxes.
Any idea's please.
Any idea's please.