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Why whole house surge protectors are not enough

TL;DR:

One measure of a surge protector is the clamping voltage. That is, at what voltage does the surge protector actually start to work. Whole house surge protectors are limited to no less than ~ 600 Volts (instantaneous) between a leg and neutral or ground. That’s up to 1,200V if symmetrical.

The best surge protecting strips and conditioners clamp below 200 Volts.

Please keep this in mind when deciding whether or not to use surge protectors at your PC, stereo, TV, etc. in addition to a whole house unit.

I wrote more about this here:

 

https://inatinear.blogspot.com/2021/09/time-for-new-surge-suppression.html

No manufacturer of whole house surge protection claims that their devices alone are enough for sensitive electronics when you check the fine print.

erik_squires
erik_squires OP
17,551 posts
 

If you talk to the folks at ZeroSurge, they will tell you that you need point of use rather than whole house

I am so disappointed in their marketing.  They miss the point entirely, and make it an either this OR that argument when it should be this AND that.

Many have unfortunately been sold on whole-house solutions being all they need, which is not true.  It’s also not true that point of use is enough, especially with so many devices we use not easy to protect with a strip.  Where the surge starts from is not that relevant IMHO.

In any event, I cover the physics in my blog.

You bring up brownouts.  This is why I recommend that the top of the line Furman with voltage regulation is the way to go.  We have all sort of power issues, from summer sags to power explosions, car accidents, thunder storms and recently had nearly 70 MPH gusts of wind.  I don’t always know what’s going to hit when so I rely on Furman with AR (voltage regulation), LiFT (noise removal), SMP (series mode surge protection and EVS (Extreme Voltage Shutdown).

About once a year EVS shuts my stereo down when I forgot I had left it on.  Twice a month power goes off momentarily.  Sometimes from storms, usually not.

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jea48
4,871 posts
 

If you talk to the folks at ZeroSurge, they will tell you that you need point of use rather than whole house because most surges are emanating from inside the house.

It’s true most high voltage transient surges are created by induction motor load appliances and or equipment found in the home.

Branch circuit wiring in the home is fed from an electrical panel. If an appliance or a piece of equipment sends a high voltage transients surge back on the branch circuit wiring what better place to suppress, clamp, it than at the electrical panel with a Type 2 SPD.

Second line of protection is the Type 3 plug-in point of use SPD (Surge Protection Device). (Type 3 SPDs should not be connected to branch circuit wiring less than 30ft in length fed from the main electrical service panel.)

FYI, SPDs should be, approved, certified, Listed, UL 1449 3rd edition.

Eaton’s guide to surge suppression

Leviton SPD / NEC 2023 code.

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