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.
@britamerican Isn’t there an NEC or UL limit to the amount of capacitance you can put on the AC line, before any primary windings?? |
@erik_squires Why thank you. Thank you very much. |
If you asked me that 15-20 years ago maybe I would have known the answer. I doubt UL or NEC would ever say the capacitor can only be this big. They will write a bunch of paragraphs that will have the same effect. 5 minutes on Google and I found maximum of 34V after 1 second. |
Caelin Gabriel and Shunyata make suppressors for medical gear so I think they're a lot more knowledgeable than most people here. I spoke with Tim from Transient Protection Design who said that their whole home unit has MOVs that turn on at 150v. I encouraged him to have his engineer write something more detailed that I could share. They also recommend a defense on depth approach for sensitive electronics, and have detailed pdf showing how a home filled with electronics might be protected. |
Great, so which of their gear has been UL or ETL tested? Do they promote any of it as surge protectors?
That is interesting if true. Are you sure that isn't how it clamps after activation? |
