Understanding Surge Protector Specs: A Guide for the Computer Age

[kiki_danc]

Since the dawn of the computer age.. I never understand much about surge protector specs. So let me ask it now.

I have a power supply model Mean Well RS-50-24

https://www.meanwell.com/webapp/product/search.aspx?prod=RS-50

It quotes : "Withstand 300VAC surge input up to 5 second"

For 220 Voltage system.. what is the joules it corresponds and how do you compute for it?

https://www.amazon.com/dp/B00009RA5Z/?tag=pfamazon01-20

Here a surge protector quotes: "Surge energy rating 680 Joules".. what VAC surge it can withstand and up to how long (in seconds)? How do you compute?

 

[kiki_danc]

But what's odd is that I've used over 30 equipments like TV, computers for nearly half a century without surge protectors.. and I don't have any fried circuits.. can anyone explain this.. are surge protectors just gimmick?

 

[Rive]

are surge protectors just gimmick?

You are just lucky. Once I've seen a whole street of people who were not lucky. Next day the local electronics repair shop got clogged with TV-sets, stacked three pieces high.

For 220 Voltage system.. what is the joules it corresponds and how do you compute for it?

When it's mentioned in Volts, it means non-standard voltage input from the utility service. When it's Joule, it means energy contained in short spikes, like a lightning strike.
That Meanwell PSU is an industrial product, so it is important to have some tolerance for rough input voltages.
That APC AVR (please next time use a source from the manufacturer) can smooth out anything between 80-130V (in case of 110V output) for indefinite time if the output load is in the specified range: it can also capture spikes up to 700Joule.
http://www.apc.com/salestools/ASTE-6Z7V37/ASTE-6Z7V37_R1_EN.pdf

 

[kiki_danc]

https://www.amazon.com/gp/product/B00966IFQ0/?tag=pfamazon01-20

Let's take the case of the above 4000 joules surge protector. If you have one tv set.. and there is lightning strike or solar storm hit nearby, can it take the blunt of the 4000 joules? or do you need to have 12 tv sets plugged in so you can take advantage of the 4000 joules protection? Normal surge protector is only 600 joules for 4 outlets.. so I wonder if the 4000 joules is due to more outlets only.

 

[Rive]

resource to study

 

[kiki_danc]

resource to study

This seems to be describing other system or using other methods. I was talking about devices or as described: https://en.wikipedia.org/wiki/Surge_protector

"A transient surge protector attempts to limit the voltage supplied to an electric device by either blocking or shorting current to reduce the voltage below a safe threshold. Blocking is done by using inductors which inhibit a sudden change in current. Shorting is done by spark gaps, discharge tubes, zener-type semiconductors, and MOVs (Metal Oxide Varistors), all of which begin to conduct current once a certain voltage threshold is reached, or by capacitors which inhibit a sudden change in voltage. Some surge protectors use multiple elements."

So the devices you mentioned were not the same as these..

 

[Rive]

So the devices you mentioned were not the same as these..

Yes, they are. Just the inductors/spark gaps/varistors/etc are inside the devices.

 

[kiki_danc]

Yes, they are. Just the inductors/spark gaps/varistors/etc are inside the devices.

Which one.. the amazon surge protector or the resource page you shared? Both has them inside the devices.. so what is the difference between them?

If my place electricity has no ground.. do you know devices are more effective that doesn't need any ground?

 

[kiki_danc]

Which one.. the amazon surge protector or the resource page you shared? Both has them inside the devices.. so what is the difference between them?

If my place electricity has no ground.. do you know devices are more effective that doesn't need any ground?

Oh. The SPDs you mentioned are put beside circuit breakers.. while surge protector strip at amazon was where you plug the appliance.. the latter uses joules rating.. while the former didn't.. I bought 5 pcs of the amazon item. I wonder if I should get SPDs instead. Hm..

 

[kiki_danc]

Oh. The SPDs you mentioned are put beside circuit breakers.. while surge protector strip at amazon was where you plug the appliance.. the latter uses joules rating.. while the former didn't.. I bought 5 pcs of the amazon item. I wonder if I should get SPDs instead. Hm..

I just found out the amazon item has clamping voltage of 500 volts.. I read it's too high. Normal should be below 400 voltt. Glad I was able to cancel it in time (it's being prepared for shipment). I got it after seeing this review:

https://wiki.ezvid.com/best-surge-protectors

I'll wait off a day before buying one.. What do you guys recommend?

For those familiar with them. The SPD doesn't have joules rating.. how do you convert between it (joules and other rating) and the surge protector strips (that is not SPD)?

 

[Rive]

The SPDs you mentioned are put beside circuit breakers.. while surge protector strip at amazon was where you plug the appliance..

Type I and/or Type II goes to the switchboard beside the circuit breakers: what you bought (cancelled) is a Type III. I've linked that paper so you can have a vague idea about the bigger picture. It is indeed more about Type I and Type II (since they are selling those).

 

[kiki_danc]

Type I and/or Type II goes to the switchboard beside the circuit breakers: what you bought (cancelled) is a Type III. I've linked that paper so you can have a vague idea about the bigger picture. It is indeed more about Type I and Type II (since they are selling those).

Problem with Type 1 and Type II is that even if the protection is lost (the varistors fried for example).. you won't know it because power still flow.. this can be disastrous for say successive wave of solar storms hitting the grid. Actually for Type III, this is also most often the case. I need APC Fail Safe feature.. specifically: http://www.apc.com/shop/us/en/products/APC-Performance-SurgeArrest-8-Outlet-120V/P-P8 (just an example)

"Fail Safe Mode
Most other surge suppressors continue to let power through even after their circuits have been damaged, leaving your equipment exposed to future surges. APC's SurgeArrest fail safe, which means that once the circuit of an APC SurgeArrest has been compromised the unit disconnects equipment from the power supply ensuring that no damaging surges reach your equipment."

I will take this as no 1 in my list of features along with high joules value and low clamping voltage and 1 ns fast response time. If you know of type 1 or 2 with Fail Safe feature, please let me know. Thanks.

 

[kiki_danc]

Most surge protector strips at amazon has 110 volts rating.. does it mean the circuit is only designed for 110 volts and I can't use 220 volts which is my voltage? What kind of strips can accept both 110 volts and 220 volts?

 

[Nik_2213]

For many years, I ran my home computers (pre-PC) via a high-end, audio-grade spike arrester module. It had a ferrite toroid the size of a hockey puck, stood off lots of domestic switching and network tap-change spikes and transients...

Now, I have a bunch of MOS-based spike catchers plugged in around the house, consider them 'consumables' and keep several spares...
IMHO, 'just one' will not suffice as MOS devices suffer both progressive and sudden attrition.

If your devices have a 'guarded' neon, please check regularly that they haven't quietly 'died in the line of duty'...

 

[kiki_danc]

Something that I'm very concerned with is regarding the fire hazard of surge protectors especially when this would be put in unattended location. See:

http://davesieg.com/your-surge-protector-can-burn-your-house-down/

"Your Surge Protector Can Burn Your House Down!

A business associate recently shared with me some shocking information about surge protectors. If you are like me, you probably have your computer and monitor plugged into an outlet strip that has a surge protector, right? They’re supposed to protect your computer in case there’s a lightning strike or a power surge, right? Well, maybe.

It turns out that the MOV’s (Metal-Oxide Varistors) that are used in Surge protectors offer a short to higher voltages but the usual 120 volts pass right on through to your equipment. Thats good right? Yes, its good if the transient “surge” is short – like 5 or 6 cycles (1/10 second). But if for whatever reason your voltage increases to say 208 volts for even just a few seconds, which can happen if the neutral line of your power feeding your house is compromised, or if there’s a problem with the power feeding your neighborhood, the MOV will quickly burst into flames! Its made even worse because most surge protector strips are plastic and the manufacturers glue the MOVs into the strip with hot-melt glue! (fuel source!)"I was supposed to use surge suppressor on the Honeywell Addressible Fire Control Panel with 20 smoke detectors. The control panel alone costs more than $1000. So here is the dilemma. Use surge protector that can cause fire (where it's supposed to be used on a fire detector) or just take chance and wait for lightning or solar storms to hit the panel. What is your option? Do you know of any surge protector strip that is fire proof? How about the SPD Type 1 and Type 2. Ae they also composed of MOV's that can cause fires?

 

[Vanadium 50]

"Your Surge Protector Can Burn Your House Down!

Hogwash and clickbait.

Yes, they are right - if the power company disconnects the 120V and connects it up to 240V, all your electronics, not just your surge protector can spark. And if an arsonist throws a Molotov cocktail in your window, that can burn your house down too.

 

[Nik_2213]

"Hogwash and clickbait."
Agreed.
Have multiple MOS devices around your house to mitigate the mayhem.
Also, if so concerned, you may need an industrial-strength arrestor upstream of your fuse-box, with a spark-gapped grounding port such as Hams etc use. This will require professional installation, testing and maintenance as, technically, it is a lightning protection system...

 

[russ_watters]

Hogwash and clickbait.

Yes, they are right - if the power company disconnects the 120V and connects it up to 240V, all your electronics, not just your surge protector can spark. And if an arsonist throws a Molotov cocktail in your window, that can burn your house down too.

...and if the gas company suddenly increases your supply pressure by a factor of 10...

 

[kiki_danc]

A Mil-spec surge protector strip made of metal may be more fire resistant than one made of plastic.. but then maybe there is danger of electrified enclosure? For the SPD type 1 and type 2. They are all metal.

I'm still trying to learn how to convert the specs in the SPDs to joules in the strip. No one know any formula?

Best SPDs would be ones where electricity would no longer flow if the surge elements are already damaged. Most in market can still make it flow.

What surge protectors are being used in the LHC or the Israeli Particle Beam Weapon Research Facility? They should be using the best surge protectors in the planet.

 

[Vanadium 50]

What surge protectors are being used in the LHC or the Israeli Particle Beam Weapon Research Facility?

Are you serious? Or just messing with us? Do you seriously believe that the LHC is plugged into a 120 V (OK, 220V, since it's Europe) power strip?

 

[kiki_danc]

I wonder if the LHC PCs and Macs still use surge strips.. although the main lines of course use SPD Type 1 and 2.
If anyone has any information about the surge protection technology used in LHC, please let me know.

Well I have spend several hours reading about surge protectors.. and have finally understood it. Now I'll share what I learnt.

First about Joules as specs... I read https://www.nemasurge.org/faqs/

"Is the Joule rating of an SPD important?
While conceptually a surge protective device (SPD) with a larger energy rating will be better, comparing SPD energy (Joule) ratings can be misleading. More reputable manufactures no longer provide energy ratings. The energy rating is the sum of surge current, surge duration, and SPD clamping voltage.

In comparing two products, the lower rated device would be better if this was as a result of a lower clamping voltage, while the large energy device would be preferable if this was as a result of a larger surge current being used. There is no clear standard for SPD energy measurement, and manufacturers have been known to use long tail pulses to provide larger results misleading the end users.

Because Joule ratings can easily be manipulated many of the industry standards (UL) and guidelines (IEEE) do not recommend the comparison of joules. Instead they put the focus on actual performance of the SPDs with test such as the Nominal Discharge Current testing, which tests the SPDs durability along with the VPR testing that reflects the let-through voltage. With this type of information a better comparison from one SPD to another can be made."

The following are excellent resources that I spent many hours reading and mastering:

https://www.stevejenkins.com/blog/2014/10/whats-the-best-whole-house-surge-protection/
https://www.mikeholt.com/mojonewsar...Protection-Questions-and-Answers~20040708.php

As summary. Power Strips surge protectors which are rated in Joules don't have full data of more important specs.. these power strips are called Type 3. Type 1 is used between the power lines and service entrance and difficult to install because you need to coordinate with the power companies and some don't install these. The LHC definitely has Type 1 SPDs (maybe specially made?). Type II is the most important because they have better specs than most type 3 and you can install this in any breaker panel. What I learned in the above sites is you need to use both Type II and III for optimum protection.

I'll quote the above for these important specifications in choosing real Surge Protector Device (whose data or specs you can't find in the Type 3 power strip surge protectors that is based only on joules).

"Comparing Type 2 Whole-House Surge Protectors
Because I won’t be installing a Type 1 SPD, I wanted to choose a high quality Type 2 whole-house surge protector to act as my first line of defense. During my comparison, I focused my analysis on ten important criteria that should always be considered when evaluating a whole-house surge protection device:

Most importantly: is the unit UL Certified under the UL 1449 3rd Edition and listed as a Transient Voltage Surge Suppressor (TVSS) on the equipment label?

1. What Modes of Protection does the surge protector provide? Ideally, a good whole-house suppressor should protect, at the very least, Line to Neutral (L-N), Neutral to Ground (N-G), and Line to Ground (L-G) on both incoming lines.
2. What is the Maximum Surge Current Capacity of the surge protector? This number should be measured in kA (thousands of amps) per phase, and essentially represents how big a jolt the unit can survive. It’s an important rating, but it’s not the only number to consider when evaluating a surge protector’s true capabilities (more on this later).
3. What is the unit’s Short Circuit Current Rating (SCCR)? This represents the maximum level of short-circuit current that surge protector can withstand.
4. What is the Voltage Protective Rating (VPR) for each Mode of Protection? This is sometimes also referred to as clamping voltage. VPR is like a golf score — lower is actually better. The VPR represents how much voltage is still “let through” to your equipment after the surge protector has done its job. When comparing surge protectors head to head, this rating should be compared based on the same Modes of Protection, and taking the Max Surge Current Capacity into consideration.
5. What is the Maximum Continuous Operating Voltage (MCOV)? MCOV is probably the most important factor to consider when evaluating a surge protector. Higher is better, and it should never be lower than 115% of the system’s nominal voltage for both L-N and L-L. For example, if evaluating a 120V/240V unit and following the 115% rule, the L-N MCOV should be at least 138V and the L-L MCOV should be at least 276V. If it’s not, the surge protector isn’t any good.
6. What is the surge protector’s https://www.nema.org/Products/Documents/nema-enclosure-types.pdf?
7. What type of warranty is offered?
8. What additional connections (phone, coax) are supported? Even if all your power cords are surge protected, surges can still travel through the coax cable that delivers your cable TV/Internet and satellite signal, or phone lines. A comprehensive power protection strategy should also include protection for these connections, too.
9. Does the unit’s price represent a good value? If one unit is more expensive than another unit, is the increased price justified based on the increased features and/or performance?"

Right now I'm looking for a type 2 SPD with lowest Let thru voltage (so called Voltage Protection Rating or clamping voltage) but most seem higher than the Type 3 power strips. This is so because the more capacity is the surge element, the higher the clamping voltage. This is why combining type 2 and 3 may be the best of both worlds as you need cascaded protection and they are called type I, II and III because they are to be used cascaded.

Now back to LHC. What kind of surge protectors do they use? Are they specially made and designed? I haven't seen a power strip surge protection that has type 2 like specs besides joules. Maybe someone can take a look at what kind of surge protectors the LHC computers (PCs and Macs) are connected to? I also plan to visit LHC next year. Can I see the computers and surge protectors they are using?

 

[russ_watters]

I wonder if the LHC PCs and Macs still use surge strips.. although the main lines of course use SPD Type 1 and 2.
If anyone has any information about the surge protection technology used in LHC, please let me know.

Nothing specific to the LHC, but local surge protection is rare in non-residential applications except as a byproduct of plug multiplying (a power strip). For anything worth saving, surge protection is just a small part of larger protection systems, E.G. uninterruptible power supplies.

 

[kiki_danc]

Nothing specific to the LHC, but local surge protection is rare in non-residential applications except as a byproduct of plug multiplying (a power strip). For anything worth saving, surge protection is just a small part of larger protection systems, E.G. uninterruptible power supplies.

But SPD type II has Voltage Rating Protection (clamping voltage) of 1000 Volts for 220 volts AC. It is too high for any 220 volts PSU, that is why power strips with low clamping voltage of about 500 Volt is still required.

I'm looking at the Prosurge with Arc Technology.. it can prevent burnout in event of power surge. But VPR is high at 1000 volts.

http://www.prosurge.com/maximum-safety-in-surge-protection/

 

[kiki_danc]

Most high quality SPD type 2 have high Voltage Protection Rating (clamping voltage). For comparison, say your 120 volts Apple Mac is encountering 600 volts from the surge protection, won't it get damaged? Won't the AC to DC converter in the PSU increase the DC voltage as well?

Clamping voltage is the voltage where the MOV would start to conduct so if it's 600 volts.. that means your Apple Mac can encounter it without the surge protector kicking into action.. what is your comment about his?

 

[russ_watters]

Most high quality SPD type 2 have high Voltage Protection Rating (clamping voltage). For comparison, say your 120 volts Apple Mac is encountering 600 volts from the surge protection, won't it get damaged? Won't the AC to DC converter in the PSU increase the DC voltage as well?

Clamping voltage is the voltage where the MOV would start to conduct so if it's 600 volts.. that means your Apple Mac can encounter it without the surge protector kicking into action.. what is your comment about his?

For this and your previous post, what you are missing is the issue of time. Damage is caused by [over]heating and heating takes time. So the 5 sec at 300V you cited in the OP is just one point on a performance envelope curve. 5 sec is far longer than it takes for a surge protector to trip, so the voltage the PSU can take from it is far higher than 300V. How much? They didnt say, but it is highly likely the problem you think you found does not exist and you are wasting your time trying to solve it.

 

[kiki_danc]

For this and your previous post, what you are missing is the issue of time. Damage is caused by [over]heating and heating takes time. So the 5 sec at 300V you cited in the OP is just one point on a performance envelope curve. 5 sec is far longer than it takes for a surge protector to trip, so the voltage the PSU can take from it is far higher than 300V. How much? They didnt say, but it is highly likely the problem you think you found does not exist and you are wasting your time trying to solve it.

I finally ordered the Prosurge SP320-S SPD with the following specs:

Most SPDs with 220 Volts AC and MCOV of at least 320 Volts has VPR of about 1200 volts.
MCOV needs to be higher than 220 Volts for head-room to avoid heating the elements, etc.

VPR – Voltage Protection Rating. A rating per the latest revision of ANSI/UL 1449, signifying the “rounded up” average measured limiting voltage of an SPD when the SPD is subjected to the surge produced by a 6000 V, 3000 A 8/20 µs combination waveform generator.
In other words, The VPR represents how much voltage is still “let through” to your equipment after the surge protector has done its job.
In the case of the SP320-S. The let-through voltage is 1200 Volts.

The 8/20 µs waveform

Won't the computer or gadget be damaged when you have 1200 Volts at 8/20 µs passing through it? But note a lightning or power plant surge also occurs very fast at 8/20 µs, why would it damage it that the 1200 volts at 8/20 µs won't?

 

[Rive]

Won't the computer or gadget be damaged when you have 1200 Volts at 8/20 µs passing through it?

Of course, it will. If you remember that paper I linked before, protection usually built on a Type2 SPD, with optionally a Type1 as 'muscle' and Type3 for the fine job. The only variation of devices which are not there is exactly when there is just one Type1 is installed.
You just nailed the reason for it.

 

[kiki_danc]

Of course, it will. If you remember that paper I linked before, protection usually built on a Type2 SPD, with optionally a Type1 as 'muscle' and Type3 for the fine job. The only variation of devices which are not there is exactly when there is just one Type1 is installed.
You just nailed the reason for it.

Gee. I have to still look for a type 3? But the problem with type 3 or the long white surge power strips is they are rated at Joules and not UL tested.. there is no specs Imax (maximum discharge current) which is the standard one uses with SPDs. So when a given strip surge has clamping voltage rating.. it's not even tested to be so.. the manufacturer just gives it and you need to believe by faith.

 

[Rive]

Gee. I have to still look for a type 3?

Check that paper again. Systems are just fine with Type 1 & Type 2 already: Type 3 is just an additional (cheap!) last line of defense.
With other words: if to be used together with a well designed Type 1 & Type system you can pick (almost) any Type 3 you want.

 

[kiki_danc]

Check that paper again. Systems are just fine with Type 1 & Type 2 already: Type 3 is just an additional (cheap!) last line of defense.
With other words: if to be used together with a well designed Type 1 & Type system you can pick (almost) any Type 3 you want.

But you just said that the computer or gadget would get damaged if you have 1200 Volts at 8/20 µs passing through it. Most SPD type 2 VPR are in the range of 1200 volts for 220v power system.. so how can you state systems are just fine with type 1 and type 2?

Another thing. Even type 3 SPD still have VPR in the 1000 volts range... see:

http://www.prosurge.com/din-rail-spd-ac-power-supply/

The type 3 has Up of 1300 volts... Up is closely related to VPR... for Up of 1300 volts, VPR is about 1000. Up is the In at nominal discharge current..

 

[kiki_danc]

Is there any electrical engineer here? Can the RS-50-24 in the following be damaged by a 1200 volts passing through it at 8/20 µs? This is the typical voltage protection rating of a SPD type II surge protector after it's done it's job.

https://www.meanwell.com/webapp/product/search.aspx?prod=RS-50

In case our electrical engineers here don't hang out in this C&T forum. I also posted it at the Electrical Engineering forum https://www.physicsforums.com/threads/can-220v-computer-be-damaged-by-1200-volts-8-20-us.955930/

 

[kiki_danc]

The SPD type 2 is finally installed in my house. Note the MCOV is 320Vac. My ac supply is 220Vac.. I can't use 260Vac MCOV because there is none and you need big good allowance because the MOV element can be destroyed if the ac fluctuates to ac rating voltage (and can cause fire).

The green square can become red if the thermal disconnect engaged from 50kA of EMP blast.

Now the problem is the VPR of 1.2kV (1200 volts). The supplier who is a licensed electrical engineer commented the 8/20usecond pulse is only very quick and not enough to heat the computer circuits. When asked for any reference. He can't give any. I think he is just guessing. He doesn't have SPDs below 1200 volts and he can't sell if he would convince his clients the computer can still get fried.

Now I'm looking for a type 3 SPD with say 10kA EMP blast resistance to be added cascaded to the above because here the VPR can be lowered to maybe 500Vac. I can't trust the power strip surge protectors because they are not tested all.. unless perhaps you have used one and can state reason why it can be trusted? What brand of strip surge protectors do you use?

 

[Tom.G]

You need a cable clamp where the wires go thru the wall of the box. At the other end of the wires too. That is a rough, sharp edge around that hole and there is a very real danger of it cutting thru the insulation in the future and causing a short circuit. Whoever did that should be called back and told to make it right. If he refuses, report him to the licensing agency!

DON'T GAMBLE WITH IT, FIX IT!

 

[kiki_danc]

You need a cable clamp where the wires go thru the wall of the box. At the other end of the wires too. That is a rough, sharp edge around that hole and there is a very real danger of it cutting thru the insulation in the future and causing a short circuit. Whoever did that should be called back and told to make it right. If he refuses, report him to the licensing agency!

DON'T GAMBLE WITH IT, FIX IT!

Thanks I'll tell the company right away.

 

[Rive]

Now the problem is the VPR of 1.2kV (1200 volts). ... 8/20usecond pulse...

To put those wires in context I believe this part of the previously linked document will be relevant: