I recently changed a service from 100 amps to 200 amps. The inside panel had a ground wire going to the water pipe. This panel is not located with the mains outside. Can I leave this ground wire hooked up or do I disconnect it? I have the grounding electrode outside connectected to the Main panel outside. Thanks... Steve
I think the problem might be that if it was previously 100A, then that bond to the water piping is probably only a #6 or #8 Cu.
With a 200A, it now should be at least #4, according to Table 250.66.
I would remove the old wire and run a new #4 Cu from the piping to the main panel outside. IMO, that's where it really belongs anyway.