Interested in protecting your outdoor A/C condenser from power surges and brownouts? This package looks to be one of the best I've ever seen:
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.
Showing 5 responses by dpop
@erik_squires Around $250. I’ve just recently discovered these, and plan on installing one on my condenser. I also have these on my humidifier, dehumidifier, refrigerator and furnace (i.e., any device I own that has a motor or compressor), even though I rarely ever experience brownouts (you never know though when they might pop up). I like to be proactive (some may call it OCD). This also looks to have one of the lowest *specified* clamping voltages (140 V) I’ve ever seen on a surge protector. Even though I already incorporate a ton of surge protection in my house, and on my video and audio gear, I may even consider adding one of these to the audio and video (non power amp) AC feed for this gear: |
I understand what you’re saying Erik. You’ve given me another idea. As of right now (and as with almost any), my outdoor A/C condenser’s earth ground goes back into the house, and attaches to the panelboard’s grounding bus bar. If we’re looking at lightning protection for a condenser (if it sustains a direct hit), one would want that strike to immediately discharge into the ground, *before* hitting the circuit breaker box, and *then* discharging into the ground via the ground rod(s) feeding the circuit breaker box's grounding bus bar. For many this may not be feasible, but in my case, my ground rod is right beside my A/C condenser. While maintaining the current condenser earth ground connection, I may install another low impedance earth ground directly from the A/C condenser to the ground rod (again, OCD). Having been a Radio Broadcast Engineer for decades, this is basically the same thing we do when grounding broadcast towers. The main ground system exists around the broadcast tower (many times incorporating a ring of ten 8’-10’ grounding rods cadwelded together), so that the strike can *immediately* discharge into the ground, *before* entering a transmitter building or studio/office building. The rest of the star ground system for the facility then feeds off of this broadcast tower base ground system. |
@erik_squires Yes, already aware, and yes, for the sake of others. One other thing (that I learned in broadcast engineering): many times a lighting strike discharge does not like to take corners. Straight wires (with the least amount of bends) are always encouraged when designing grounds that will dissipate and discharge lightning strikes quickly into the ground. Also, due to the skin effect of wire at certain frequencies, and the general frequency (spectrum) of a typical lightning strike; in the broadcast world, we almost always use 3"- 5" copper strap (very low resistance with lots of surface area) when dealing with lightning and grounding. |
Here's another surge protector that has a very low (specified) clamping voltage (135V), as compared to many other surge protectors that don't clamp until 300 volts, or even as high as 600 volts. The linked surge protector may be marketed as a refrigerator surge protector, but it could still be used for audio and video surge protection, especially since it has a very low clamping voltage. |