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
Post removed 

Please don’t comment on something you know nothing about.

 

@vinylshadow Given your series of posts I find your choice of words really funny.

I was only half joking when I wrote "safety be damned".

I would say the same thing about the person who wrote this. They either don't know what they are doing or are lying.  I get the impression the UberBUSS is like the BlueCircle and TLP products. Stack as much capacitance across the line as possible, safety be damned!

Then I came across this for a different product that has their PFC function on whatsbestforum.


 

I get the impression the UberBUSS is like the BlueCircle and TLP products. Stack as much capacitance across the line as possible, safety be damned!

 

@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??

@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??

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.

Caelin Gabriel and Shunyata make suppressors for medical gear so I think they’re a lot more knowledgeable than most people here.

Great, so which of their gear has been UL or ETL tested? Do they promote any of it as surge protectors?

spoke with Tim from Transient Protection Design who said that their whole home unit has MOVs that turn on at 150v

That is interesting if true.  Are you sure that isn't how it clamps after activation?

Did I miss the response to what we think about "Envionmental Potentials" as a protective technolgy? VH Audio has always seemed to be edgy, but grounded in things that work, and they carry their products. I would really love to have more protection for my system than the whole house Leviton I have and several Shunyata Defenders plugged into my amps dedicated lines.

Caelin Gabriel and Shunyata make suppressors for medical gear so I think they're a lot more knowledgeable than most people here.

 

Than most people here is not setting a very high bar but even then I am not sure. They say a lot of dumb stuff.

150 vrms. They use 140v MOV probably. Not doing anything till 240 DC. A big surge is going to be over 400V.  The datasheets don't give a lot of details. 

What's the controversy?  Whole house plus a power bar for surge protection. Seems pretty obvious. MOVs don't do anything to your audio. Crazy to believe they do.

 

The article I referenced in my blog has the only independent survey if surge protector performance I know of.  Furman and Tripp Lite measured among the best with the lowest measured let through voltages.

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:

RSH-50 VRM KIT

@dpop I've never seen over/undervoltage protection for residential AC units, so that is pretty cool. I hope it's not extravagantly expensive.

We do see AC unit surge protectors around here though.

@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:

Heavy Duty 20-Amp 2400-Watt Appliance Surge Protector

Interesting!! Based on what I've read about lightning striking outdoor AC units directly I really think that it's our outdoor units, not our stereos, which need a separate panel.  That is, if I could redo my house wiring, I'd run a panel from the meter straight to the outdoor heat pumps, with their own breakers and surge protectors, and another line from the meter into the house.

I mean of course to meet code 100%.  What I'd avoid if building new is to have the electricity come inside to a service panel then back out to AC units.  As it is, any lightning striking those outside units gets to come inside before meeting a surge protector.

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.

@dpop That is an excellent idea.  As you know, for the sake of others who may read this, you may not have separate grounds, but so long as you bond everything at the same ground potential you may run multiple ground conductors to the same grounding rod(s), which probably should be plural.  

@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.  

Just to lower the tone for a moment, I did a trip around the house and found that two of my surge suppressors were no longer suppressing anything. One replaced, one on order. Goes to show - some attention required.

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.

ENDMAN Refrigerator Surge Protector Three Outlet Voltage Protector for Home Appliances with Time Delay, Protects Against Brownout, Spike, Instant Surge All Voltage Abnormalities