Surge protector for AC units. Real need or scam?

All services on new houses have surge protectors installed in the main panel

I have the FS140 whole home protector on my house.

Siemens FS140

Siemens FSPD140

Both are rated for panels up to 400A and meet NEC requirements (e.g., 2020/2023 editions for surge protection).

The FS140 is sometimes marketed as a "Pro" model for higher-end residential or light commercial use due to its GRM feature, while the FSPD140 is positioned as a straightforward, user-friendly residential option.

If your setup involves a surface-mount panel or you prioritize ease of installation, go with the FSPD140. For deeper integration with the panel and extra ground monitoring, the FS140 may be preferable.

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Is this just a new sales pitch or is there a legit reason to install surge protectors?

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The more efficient and new items get, the more intricate the electronics get. If you notice, almost every appliance has its own circuit board and electronics inside. With the addition of tvs, routers, variable-speed AC compressors, etc. into homes the greater chance of these items becoming unusable in the event of a lightning surge.

So do I think you need surge protectors at each AC compressor? Not necessarily but it’s a good idea to have one on your main panel as others have suggested. I have an Eaton one from HD in my panel and my house was built in 1987. Installed it myself pretty easily - required a 2-pole 50A breaker and then landed a wire on the neutral bus and ground bus. Done.

You know the numerous posts on this board on HVAC capacitor failures? Temperature, which you can’t control, and voltage surges, which you can provide some degree of protection, are the main causes of HVAC capacitor failure. I’ve never had an anything messed up with a voltage surges either but I had a HVAC surge protector installed during a HVAC changeout a couple years ago.

6 months later when I had interior house renovations on going and a electrician at the house doing other stuff I had him install a whole house surge protector. With circuit boards in just about every appliance in your house, not a bad idea to consider a whole house surge protector.

When Hurricane Francine came through BR in Sept last year and I had 1/2 dozen power surges- brownouts over a 2 hour period (never lost power for more than 3 or 4 seconds), I was glad I had those surge protectors.

ETA: I have the Siemens FS140 Whole House Surge Protector.

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Did it trip the surge protectors? My understanding is they are single use and give an indication when they are tripped.

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Nope - first thing I checked, and I always check it, after a power outage. The small surge protector installed on the HVAC disconnect to protect the condensing unit is single use. Green light on it’s good, red light on needs to be replaced. The whole house Siemens FS140 has a 5 or 6 (can’t recall from memory) trip capacity.

For what it is worth, lightning struck a tree between mine and my neighbor’s house a while back. His AC was toasted and mine survived, because mine had a surge suppressor. His homeowners insurance did cover the damage.


Short story is, I would probably have one installed on a new unit, but not on an existing one.

I had a surger blow the plug off my compressor and a hole in the side of it. Compressor still spun freely. My AC guy replaced the compressor (part under warranty) and I asked him to put in the AC surge protector I bought off Amazon while he was doing the work. He didn't charge me for the extra 5 minute effort while he was there.

Intermatic AG3000 $73 part at Amazon