Two Surge Protectors?

Jim Norman wrote:
My built in unit is a Surge Guard 41260, protects to 2600 joules,

So that Surge Guard will 'absorb' 870 joules and not more than 1750 joules. Potentially destructive surges can be hundreds of thousands of joules (clearly not billions of joules). That Surge Guard is electrically similar to other tiny power strip protectors. Effective protector works because it is earthed. And does not 'block' or 'absorb' a surge.

What was posted previously completely applies. Especially the part about how a protector must connect low impedance (ie less than 10 feet) to earth to protect from that type of anomaly. What happens when its near zero joules try to 'absorb' that energy? Those numbers should cause you pause.