I have a 400 amp service. I thinks it's really just 2, 200 amp services run to 2 separate panels. There are 2 separate shut offs outside, but just 1 meter. I also have a 100 amp generator panel fed from the second 200 amp panel. Can I use just one whole house surge protector or do I need one for each 200 amp panel. There is plenty of room in the 200 amp panels, but the 100 amp generator panel is full.