# How useless are Power Surge Protectors with 500V-800V Clamping Voltage?

#### c627627

Joined May 18, 2011
55
If correct, my understanding is that when you look at Power Surge Protectors, you look at the Clamping Voltage first - and only then the Joule rating. From a reputable UL certified company.

I have a 3,000 Joule Power Surge Protector but it has a high 500V Clamping Voltage, more than the 'at least' 330V-400V usually recommended [lower is better]. I also have a 4,320 Joule one with a huge 800V Clamping Voltage spec.

How useless are these Power Surge Protectors with clamping voltages so high?
Are they really just expensive power strips with no protection, since they will not "kick-in" in time to save your equipment with clamping voltages so high?

Separate question, are there any down sides to plugging them into a surge protectors with 150V clamping voltage with lower Joule rating?
Let's say you have a 150V CV but only 1000 Joule model.
So you plug it into the wall
and then plug into it
the 4,320 Joule one with a huge 800V Clamping Voltage.

So do you now have 4,320 Joules [plus the 1000 Joules + 150V clamping voltage]?

Similarly, my battery backup UPS only has a 490 Joule rating with no listed Clamping Voltage.
Can I plug a decent surge protector into it?
Battery backup companies don't want you to do that, but what does the math say?

#### LowQCab

Joined Nov 6, 2012
1,929
You can stack them up in parallel as many as You like, and they will all add together,
they will only "kick-in" at their individual Voltage-ratings though.
Just buy a Bag of seriously Heavy-Duty MOVs, and solder them in yourself.
This is a great way to make your own "protected" Plug-Strip out of an "unprotected" one.

You can also get HUGE ones that install inside your Electrical-Panel, more is better.
Plugging-in "Protected" Strips or Outlet-"wall-worts" in every room in the House
will all add-up together for better "whole-House" suppression.
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#### c627627

Joined May 18, 2011
55
You are thinking big picture, and your answer addresses the actual core issues better, but for educational purposes, I'd like to find answers to the thread question.

Let's say we are only talking normal house scenario, and we are choosing a surge protector. Is the first statement correct: "...when you look at Power Surge Protectors, you look at the Clamping Voltage first - and only then the Joule rating. From a reputable UL certified company."

If so, is the second statement correct: that you need to get one with 330V-400V Clamping Voltage and not higher?

And then if that is so, what does that say about a surge protector with an 800V Clamping Voltage, even if its Joule rating is 4,320 Joules... I am trying to get answers to these questions as faced by someone who does not have your knowledge of modding electronics. On multiple forums, so far unsuccessfully.

#### LowQCab

Joined Nov 6, 2012
1,929
The answer to the first question is True.

The second question starts to get fuzzy.
Lower Voltage / higher "Joule-rating" MOVs can be purchased,
and definitely offer increased protection,
but,
You are not likely to find them in commercially available "consumer-appliances"
simply because they may cost ~$0.04 Cents more than the cheezy one that they can "get-away-with". 4-Cents, times a million units produced, starts to add-up to a sizable chunk of Money. 800-Volts is a complete joke, look no further. Lower-Voltage MOVs partially conduct ALL THE TIME, therefore they produce Heat, and may waste several Watts of Power. Large, lower-Voltage MOVs, are also physically large, and must have proper ventilation to prevent over-heating, and melting of Plastic-Housings. Welcome to the corporate world. That's why, when it really matters, You have to provide your own insurance. . . . Thread Starter #### c627627 Joined May 18, 2011 55 Okay, tell me what you think of usefulness of these four in real life: 330V, 1,440J vs. 330V 2,160J vs. 500V 3,000J vs. 800V 4,230J Last edited: #### LowQCab Joined Nov 6, 2012 1,929 I personally wouldn't even consider anything over ~330-Volts, ( with 220-Volt Mains ), as being useful. Want more Joules ?, buy 2, 3, or 4 of them, they're dirt-cheap. When they're all on the same physical Branch-Circuit, the Clamping-Power is added together. . . . Thread Starter #### c627627 Joined May 18, 2011 55 Oh!? So if you have a 330V 2,160J and a 800V 4,230J, what do you plug into what, to get what end result specs-wise? Thread Starter #### c627627 Joined May 18, 2011 55 You also appear to have answered one of the important questions. My old 800V 4230J and my old 500V 3000J Surge Protectors are nothing but glorified power strips with no real surge protection, because of their high clamping voltage, correct? For$19.99, I bought a few of these 330V 2,160J,
Actually Tripp Lite says Clamping Voltage (RMS) is 150V:
https://www.tripplite.com/protect-i...or-7-ft-cord-2160-joules-white-housing~super7

How acceptable is that, how does 2160J compare to 2880J
This model has the same low clamping voltage but with 2880J vs 2160J:
https://www.tripplite.com/protect-i...les-tel-modem-coaxial-protection~tlp1208teltv

#### Delta Prime

Joined Nov 15, 2019
1,326
Hello there! You should be aware that Joules are cumulative!
If you have a 2000 Joules rated surge protector & it takes a hit worth 200 joules, it is now an 1800 Joules surge protector.Also look for search protectors with one nanosecond response time. A 10 nanoseconds response time is too long.
If you're in the United States make sure that the UL 1449 marking is on the front of the packaging in plain sight,the UL 1449 marking on the product means the surge protector has passed all regulatory standards.

#### LowQCab

Joined Nov 6, 2012
1,929
Forget about the Joules Specification.
If You take a direct Lightening-Strike, nothing will save your equipment,
unless maybe You have a full-tilt Lightening-Protection-System installed on your House,
and even the best of those systems don't always work.
Voltage is what counts.
Tripp-Lite is a good brand to stick with.
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#### c627627

Joined May 18, 2011
55
This arstechnica forum reply to me accurately sums up everything I ever saw on this topic in the last twenty years:
"I think a lot of us here are fatigued from previous discussion threads about surge protectors. The way they work is not as obvious as the marketing department's joule numbers would indicate, and it's too easy for people to take some basic electronics knowledge and assume too much.

If you don't know specifically what you're doing, read the instructions that came with your UPS and surge protectors and follow them, obeying all safety-related information from each."

Nobody really knows is what arstechnica forums reply says.

I think I'd like to simplify things and maybe just try to see if we can express opinions on this simple choice of two:
IF YOUR CHOICE IS ONLY THESE TWO, and they cost the same, which would you pick to connect your expensive OLED TV and stereo system to and why?

• Exhibit A is Tripp Lite SUPER7 with 150V RMS to 330V Clamping Voltage and 2160 Joule Rating
https://www.tripplite.com/protect-i...or-7-ft-cord-2160-joules-white-housing~super7

• Exhibit B is Tripp Lite TLP128TTUSBB with 800V Clamping Voltage and 4320 Joule Rating
https://www.tripplite.com/protect-it-12-outlet-surge-protector-8-ft-tel-fax-modem-coax~tlp128ttusbb

Exhibit B costs 50%+ more but for the purposes of equal comparison, assume they both cost the same.

#### Delta Prime

Joined Nov 15, 2019
1,326
Nobody really knows is what arstechnica forums reply says
"Non ducor duco"

#### c627627

Joined May 18, 2011
55
As far as UPS and Surge Protector combo:

APC says NO to UPS into Surge Protector:
"Plugging your UPS into a surge protector may cause the UPS to go to battery often when it normally should remain online."

APC says YES to Surge Protector into UPS:
[Sort of - AS LONG AS YOU DON'T OVERLOAD]
If you overload, (draw too much power) then this may be "...causing the UPS to report a lower percentage of attached load than there actually is. This can cause a user to inadvertently overload their UPS. When the UPS switches to battery, it may be unable to support the equipment attached..."

In other words, APC says YES, but only if you don't attach too many power hungry devices.
In my case, a router will not draw too much power - so it should be okay.
It would be nice to know what constitutes "too much draw" however.

#### LowQCab

Joined Nov 6, 2012
1,929
All of the Surge-Protection should be before the UPS in any case.
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#### c627627

Joined May 18, 2011
55
Thank you.
Could you offer a counter-argument to them saying UPS INTO SURGE wears out the battery.

And also why it's not a good idea to do SURGE INTO UPS, if UPS (in my case) is low-cost and only serves to allow me to save work in case of power outage - but the router being plugged into Surge is expensive. So plugging SURGE INTO UPS allows me both to "obey" what APC is saying and also protect the router somewhat more.

#### LowQCab

Joined Nov 6, 2012
1,929
"" And also why it's not a good idea to do SURGE INTO UPS, if UPS (in my case) is low-cost and only serves to allow me to save work in case of power outage - but the router being plugged into Surge is expensive. So plugging SURGE INTO UPS allows me both to "obey" what APC is saying and also protect the router somewhat more. ""
This whole statement is very confusing.

And also why it's not a good idea to do SURGE INTO UPS,
Do You mean "before" the UPS ? and not "after" the UPS ?
Put all Surge Protection before the UPS, not after.
There is no need to use Surge-Protection after the UPS.
The UPS has Surge-Protection built-in.

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- but the router being plugged into Surge is expensive
Expensive in what way ?
The Router does not need "extra" protection,
Everything needs protection, including before the UPS.

You can provide additional Surge-Protection by
simply plugging-in more devices that have MOVs built-in.

A Surge-Suppressor protects an entire Branch-Circuit coming from your Electrical-Panel.
The more Surge-Suppressors that You have plugged into that Branch-Circuit,
the greater the "Protection-Level" becomes for everything on that Branch-Circuit.

The Circuit-Breaker in your Electrical-Panel is what actually provides the "Protection".
The individual MOVs in various pieces of equipment are what create
an additional Electrical-Load, but only during a "High-Voltage-Spike-Event",
which causes the Circuit-Breaker to "trip" much faster than usual,
thus helping to protect the equipment on that Branch-Circuit.

This is why it is advantageous to Plug-in Surge-Protectors everywhere inside your House,
even if nothing is plugged into them, they still function.
Their effectiveness is cumulative,
they all add together to increase the overall protection of everything in the House.
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