SPD Question

[Armsil2468]

I have an Eaton surge protector (BRNSURGE) installed at my house but my subpanel which is about 30 ft away is a square D brand and only protected by the upstream SPD. Can an electrician install the HOM250PSPD surge protector on that panel? I understand that I only need one, but will this cause a problem? I ask because the square d SPD seems to have much better specs. Is two better than one when the main panel and subpanel are different brands? The house is 3 years old. Thanks.

 

[tom baker]

Mike Holt said
More is better
You get what you pay for

At the service panel install a wire spd
Then your square d at the subpanel

 

[Armsil2468]

Mike Holt said
More is better
You get what you pay for

At the service panel install a wire spd
Then your square d at the subpanel

Thank you for the reply. I Also want to add that my homes a/c is variable speed (Trane XV20i). I assume this is also ok?

 

[paulengr]

Surge protectors give you the rating at the end of the six inch pigtails in the wiring. As you move away from the surge protector pigtails the voltage that it protects to goes up 20 V per inch. So if the MCOV is 300 V at the main panel it’s only good for 7500 V 30 feet away. Surge protectors are wired in parallel. The word “upstream” means nothing. Code only requires one at the main panel to protect the AFCIs. There is a particularly nasty issue with power electronics so they come automatically with some surge protection.

The stuff the utilities use on poles, the stuff in your house panel, and the stuff in a $20 “power strip” is the same stuff. It is sintered metal oxide powder (mostly zinc) formed into discs. That’s right, sun screen (zinc oxide) is in your surge arrester. The only difference is the thickness and diameter of the zinc oxide discs. Obviously you should get a little more if you pay more. But don’t think there’s any serious difference within a certain category,