Whole House Surge Arrester

I want to point out something that is often overlooked.

Whole-house surge protectors do protect everything from surges outside and inside, BUT, they have typically have high let-through voltages of 600V. They may list 150V MOV’s but the listed let through is what’s important.

You get great protection for major appliances, fire alarms, home automation, etc. but not really very good protection for delicate equipment with semiconductors that can die with an extra 20 V across their terminals.

Read the recommendations and instructions carefully and read the equipment warranties with this in mind.

With a new house build our electrician installed in our Eaton panel whole house  surge protectors which occupied two slots and would last as long as they were not "invoked".  Once they trap a surge, they need to be replaced.

In our former home, I had a Leviton 52000 series whole house surge protector, which was much more expensive and much more sophisticated, with two replaceable "modules", when one would trap a surge, it would need to be replaced.  If my memory serves me, I think we paid something like $1200 for the Leviton unit about 20 years ago, plus labor.

To clarify what @ejr1953 is saying, WHSPs wear out. That's the joules rating. They can wear out from one big surge or a bunch of little one's over time that add up.

Unlike biological entities, WHSPs don't heal.  Once the MOV takes a surge, even a small one, it has begun to degrade.  The Leviton units with replaceable MOV modules are pretty cool in that they are meant to be replaced by your average homeowner, but are they even available in the US?

I've updated my whole house surge protection page.

https://speakermakersjourney.blogspot.com/2022/04/whole-house-surge-suppression-for-geeks.html