AC Surge/Lightning Suppressors

I was stunned to see so much good advice without mention of the most important aspect of any suppression system...grounding. We see many systems in which antenna, satellite, or cable lines into the home are not grounded properly (a violation of electrical codes) and systems with loose or corroded ground connections. Without good grounding, no surge suppressor can work properly.

Also, it is important for surge suppressors to have protection across all three combinations of the ac lines, hot-gnd, hot-neutral, and neutral-gnd. If the grounding is faulty or becomes damaged, some protection may be found in the other pathways.

Thanks Leonard!

Nice article!!

I would like to add that even though a "Ground" light or "Fault Protection" light indicates the unit is connected to a grounded plug, that may not be the case. A grounded satellite system which is powered by that surge unit may give a false indication that the unit is plugged into a grounded outlet. This article explains further. http://www.dbsinstall.com/diy/Grounding-8.asp

I've found alot of telephone line surge suppressors prevent the caller id signal from getting thru to the intended decoding device. Any suggestions ?

Carlsdad, great addition and huge point. I carry an outlet checker with me!

Hi -

I've read these 'posts' and now am curious about one item.....no one seems to have mentioned a specific #6
copper ground (literally) from the metal mast to a copper-clad steel rod in the earth, using the appropiate connectors. This was the case....has it been altered?
And, of course, it would have to be a residence, NOT a commercial building, etc.. eli whitney

That has to with installing an antenna and is not directly related to the topic of this thread. Bear in mind that if each topic or article were to cover every little parameter it would quickly become a book.

Richard...

Gotcha!! understood. eli whitney

I read your article re the surge protector. I bought a thirty-eight dollar one from Costco and plugged all my perpherials into it. The only problem is is that I get better reception/clarity of vision via the wall socket than I do when using the surge protector. I was befuddled for when purchasing it I thought it would be the very opposite of what I am experiencing. All the other products seem to work fine and they are plugged into the surge protector.

jtmj

Hello--
You WERE expecting...improved vision/clarity by having a surge protector?? Perhaps you are confusing these with a "constant voltage'" unit, ???

In any case, improving your HDTV's picture quality has NIL to do with that surge protector---think of those as a "sophisticated fuse unit" or the like to protect that equipment from INCOMING problems from the 120V-
NOTHING ELSE.

IF you have too many watts in that strip ( above it's rating ), then, it should trip the built-in circuit breaker.

Picture Quality improvement is another search.

Perhaps you could give more about what your problem(s) were to start. everett whitney

Eli is correct in terms of AC conditioning and removing noise.

What you are talking about is signal input loss by using the RF jacks. This means your signal is already low going into the house or is being dragged down by a poorly balanced cable distribution system in the house. Call you cable company to get that checked. Bottom line is you will not be fully protected from lightning unless you use it.

There is a lot of misunderstanding about lightning protection and surge protectors even in the trades.

Most lightning damage is done, not by direct lightning strikes, but strikes some where in the area resulting in surges or spikes coming in on the telephone or power lines. The magnitude of these surges in tiny compared to a direct or even close strike, but they are small enough that a surge protector can swallow them without usually leaving scorch marks.

The single most important item about lightning protection is grounding and that is a "single point ground" where every thing being used ties to the same ground. That way if there is a strike or nearby hit, all lines, such as electrical, telephone, cable, and TV antenna rise together. There may still be some differences, but they are more likely to be only a few volts instead of thousands. A good ground system like this will let the surge suppressors do their job if they need to. However it does little good to run the AC line and coax through a suppressor and then plug the phone line directly into your receiver.

A good ground is not just a single 8 foot ground rod at the base of the TV antenna mast. For safety it takes a fairly elaborate ground.

My top antennas are at 130 feet. They have been taking an average of 3 *verified* direct hits a year. Those were seen, how many there have actually been I do not know. What I do know is since finishing up the ground system and connecting it as a single point ground I've had no damage with all those direct hits and I do not use surge suppressors. I also have 5 computers hard wired to a Gigabit network with a 130 feet of CAT5e cable that runs within 10 feet of the base of my tower.

Lightning is unpredictable and lightning strikes are not created equal. Proper precautions can minimize the risk, but there is absolutely nothing that will protect a system from one of the so called "super strikes" that are many times more powerful than typical strikes.
http://www.rogerhalstead.com/ham_files/Tower30.htm is a photo of my tower and back yard. the Dish Network small dish is not visible but it's about 15 feet up on the side of the big tower that lines up with the back side of the house. OTA TV antennas are at 90 and 95 feet. It's not a typical TV antenna installation nor is the ground system typical with 33 8' ground rods CadWelded (TM) to over 600 feet of bare #2 copper wire. But it works, or has for the last 5 or 6 years.

That has to with installing an antenna and is not directly related to the topic of this thread. Bear in mind that if each topic or article were to cover every little parameter it would quickly become a book.

Thing is, a good, well designed ground system that includes the mast/tower, cable, satellite, telephone line, electrical feed, and any other services coming in the home determines how hard the line filtering/suppressors have to work. With a well designed ground *system* the surge suppressors can be much more effective and last longer. Even the best surge suppressor installed in a system without a good and balanced ground may prove ineffective in protecting equipment from a nearby strike. So the mast grounding if done properly is directly related to how well the suppressor can do its job or even if it can do its job.

Very nice post, I am a newb and found it to be rather enlightening. Do you have any recommendations for lightning and surge protection. I live in Central Florida (the lightning capital of the US I think) and have had some appliances bite the dust from electrical surges. I do not think we have had a direct lightning hit yet (knock on wood). I want to be sure my new investment is protected from low or high surges and direct hits if possible. I use an APC UPS for my desktop, but after reading the article I don't think I am really protected since I have some peripherals plugged in to wall outlets (time to clean up the dust bunnies and rewire). Do you think a UPS would be ok, or should I get a power conditioner also? Do I need a battery back-up?

Any help or suggestions will be greatly appreciated !

Welcome to HD Library!

It is difficult to recommend specific products. If you follow the article and comments you should be able to find the right product for your application. As an example the article helped you discover that your desktop isn't actually protected and it appears you fully understand why.

The article isn't about power conditioning. Check this link for that kind of discussion...

Waveform 14 AC Power Part 1
http://www.hdtvmagazine.com/forum/viewtopic.php?t=4520

Waveform 15 AC Power Part 2
http://www.hdtvmagazine.com/forum/viewtopic.php?t=4539

A UPS, uninterrupted power supply, is supposed have batteries - that's the whole idea. The size of the battery(s) and how much power the equipment consumes that you have connected to it determines how long it will stay on during an AC power loss. As for protection that is all covered here. Does your UPS have the necessary connections for what is coming in from the outside world? Does it state that it will cover lightning and power surges? What is the amount of insurance coverage provided if it fails? This is no different than figuring out what lightning/surge suppressor you should buy.

Yes, you could buy a lightning/surge suppressor that covers the connection issue and plug your UPS into that strip.

UPS products are typically not recommended for A/V systems because most output a square wave rather than the same sinusoidal AC that comes from your wall. This means it is fine for PC applications but will degrade your audio and video performance in a home theater.

Whole house protection would cover appliances provided they are only using an AC power cord. Exception? LG has a fridge with a TV in it...

First, the installation of suppressors is not a simple matter so taking the entire ground system into account is a requirement and appropriate.

Were it me (and it's not), I'd start with a "whole house suppressor" that works on the AC mains and telephone lines at the entrance (contact your local electrical supplier. You may already have one, particularly being in Florida). A good UPS is a plus if it is properly grounded. Other items coming into the UPS and computer(s) need to use the same ground and if powered off another circuit they should be the same length following essentially the same path. Grounds for the satellite dish and OTA antenna should be the standard 8' and in some places the code requires 10' rods which should also be tied directly into the ground rods for the house electrical system. This sometimes results in a ground cable run around the outside of the house.

The protective outlet strips are good if properly grounded. Improperly grounded they can add to the problem.

You mentioned a "line conditioner" which can be good for spike suppression, but they are expensive. A line conditioner is really a UPS that is running all the time. IOW the output is always fed from the battery and much "beefier" than a straight UPS.

Hello crackerman58 -

Unnecessary Power Conditioners, over-hyped HDMIs & the like are what has made the "M" corporation one of the Richest Outfits around!

Unless one literally does generate his / her own electric power - NO - one isn't necessary in this nation!

Just get your APC, Tripp-Lite, Name Brand, UL approved surge protector, keep the carton plus paperwork for the "always included Insurance" , do check the home's grounding as Roger explained & relax!

Here is a typical unit, listed by maker as appropriate for HDTVs - - -

http://www.walmart.com/catalog/product. ... id=3910296

Anything really sufficiently close to "fry" your things will also do the same to the surge protector & that's what that "insurance " is for.

eli

If it does fry the surge suppressor, it did its job. When MOVs conduct to failure, that failure is almost always a dead short that opens the protection in the SS and/or throws the breaker.

I have serviced hundreds of systems and found that most that are properly protected with system local surge suppressors that have all signal lines protected, and where there are no grounding problems in the system, are usually not affected. I have seen many cases where many appliances, phones, irrigation controllers, and other electronics were fried, but well protected electronics were fine. It does not take an expensive surge protector to do so, just good basic protection on all signal lines and on the a.c. Of course, proper grounding is an essential part of that protection.

A couple of things that just don't make sense. UPSs aren't recommended for A/V systems because of the ratty wave form? Who cares? Why would some one care and if they do they don't know how a UPS works. A good UPS does basically two things. It protects equipment from voltage surges both high and low as well as spikes from near by lightning strikes. You don't run your equipment off the UPS itself. During normal operation it only serves as an outlet strip with surge suppressors. The UPS only kicks in to protect the equipment in case of Low or high voltage and spikes. It's supposed to keep things running long enough to shut the equipment down properly, not support the equipment in normal operation. To repeat: In normal operation the good ones only serve as a protected outlet strip. So distortion on the output of a hi-fi set should be a non issue. Now that is the job of line conditioners, but they are normally as much as 10 times or more than the price of a good UPS because they have to protect the equipment AND produce a good sine wave output. So due to price they are not usually considered a normal way of protecting equipment.

Yes the surge suppressors and strips are a good idea IF the house has a good ground system as Icailo stated. They are also the most economical. OTOH research the net for the quality of the insurance they offer. Many have so many outs, the insurance is worthless in most cases.

TO : ALL

Many Models out there - here's one by a major mfg that has "done" very well over many samples for me these past years . . . . http://www.samsclub.com/shopping/naviga ... tem=414268

eli
p.s. -
also @ Wal-Mart, of course - but - more $$$

Sadly, used to be assembled here . . . .

If it does fry the surge suppressor, it did its job. When MOVs conduct to failure, that failure is almost always a dead short that opens the protection in the SS and/or throws the breaker.
Protectors do not work that way for so many reasons.

Will that fuse or circuit breaker stop a surge? Surges are done in microseconds. Fuses take milliseconds to blow. Anyone who is making a recommendation should have that basic knowledge.

Will a fuse or circuit breaker block thousands of volts? Read numbers on those breakers and fused. 250 volts means a higher voltage simply keeps conducting through that fuse even after the fuse blows. It does not stop any surge.

That ground tester (that another uses) does nothing for what is discussed here. For example, does that outlet tester report an earth ground exist? Of course not. But more important is the nature of that ground connection. Thicker wire means lower resistance. Resistance is not relevant. Lower impedance is critical. That means a shorter wire is more important than a thicker wire. Essential to earthing a surge is a connection to earth as short as possible. Wall receptacles safety grounds are just too far away.

Other problems. To earth a surge means no sharp wire bends. No splices. Wire separated from other non-ground wires. Not inside metallic conduit. Just more reasons why a safety ground is not earth ground AND why power strip protectors do not even claim to provide protection in their numeric specs.

Essential to surge protection is no surge energy inside the building. A surge inside the building will seek earth ground destructively through household appliances. A surge that does not enter the building is, instead, harmlessly absorbed in earth. Where does that energy get dissipated?


Where ever surge damage must never happen, earthing is upgraded and a 'whole house' protector is installed. Does your telco use plug-in protectors? Or do they just disconnect phone service when ever a thunderstorm approaches? Neither. They earth a 'whole house' protector on every wire of every entering cable. A surge earthed before it can enter the building means protection inside every appliance is not overwhelmed.

Homeowners can install the same solution for about $1 per protected appliance. More responsible companies such as Intermatic, Leviton, Square D, Siemens, and General Electric provide these effective devices. A Cutler-Hammer 'whole house' protector sells in Lowes for less than $50. If properly earthed, then protection inside appliances is not overwhelmed. After all, what protects electronics in the dishwasher, smoke detectors, clock radios, and furnace?

What is inside the Monster Cable protector that sells for $150? Same protection circuit also found in the $7 protector sold in a grocery store. And the numeric specs for both make the same protection claims. Neither claims to protect from a destructive surge that is seeking earth ground. Earth a 'whole house' protector so that even direct lightning strikes cause no damage AND so that nobody even knows the surge exists. So that even direct lightning strikes do not damage the protector.

Money wasted on plug-in protectors is better spent upgrading the earthing. A protector is only as effective as its earthing.

All of these items are important for surge protection and Westom made some good points, but I think I should make some distinctions: BTW as a background in addition to over 100 credit hours in college electronics courses with a Bachelors in Computer Science, I taught every thing from introductory electricity to semiconductor circuit design and analysis to digital logic in the skilled trades program for a large multinational corporation before retiring.

First, we should not confuse surges with spikes. Surges may go high or low with durations in seconds to sometimes minutes. Spikes OTOH are just that. They are a pulse with a rapid rise and fall time. (Technically referred to as Dv/Dt, or voltage change "Dv" versus time "Dt") Surges may contain a lot of energy, while spikes are *usually* a high voltage with low energy.

In a home with a good ground system and hopefully a full house suppressor at the entrance, the so called surge protection outlet strip is a good investment. It is unlikely to protect against surges, but does a good job on spikes. A good UPS, properly configured will do a good job of protecting against surges and it should have spike protection built in. BTW, MOVs have a finite life. Every time they conduct they use up a little bit of themselves until eventually they reach a point where they conduct at too low a voltage to be of any use. They can fail either open or shorted, but shorted is the usual mode.

Backing up a bit. It's not a hard and fast rule but, surges normally come in on the power mains while spikes can and do, come in on anything. If lightning is anything it is unpredictable.
What it amounts to is the best defense is a good "single point" ground system followed by whole house suppression at the entrance. Please Google "single point ground" as this can get complicated in a hurry and I don't want to use the forum for an article.

There is no absolute protection from a lightning strike. The best we can do is follow the rules which will minimize the damage a direct or nearby strike can cause.
The whole house suppression helps protect from high voltage spikes coming in on the power mains or telephone lines. Don't forget that coax from antennas and the cable company should be properly grounded before they enter the home and that ground should be tied into the whole house, single point ground.

Another thing to remember is the idea behind the single point ground is everything at any given area in the home rises and falls at the same rate and potential. (if all goes well) Also power surges and spikes do not need a physical connection to the outside world to do damage in the home. A normal lightning strike a mile away can induce as much as a 1000 volts per meter in a piece of wire. With everything properly connected to a single point ground a piece of equipment like that new HDTV can rise to several thousand volts, but as long as the coax, interconnecting cables, AC line, telephone line, and ground also rise to the same voltage at the same time there should be no damage to even sensitive solid state devices.

One more thing. Fuses. A fuse has only one primary purpose. To prevent a catastrophic failure that burns down the house. It is not there to protect the equipment. That is taught way back in beginning electricity.

Lightning and surge protection can become quite complicated and I could write far more, but I think this pretty well covers the basics.

Our members have shown this topic can become quite complex, intense and down right intimidating. Don

Newer homes have plastic rather than metal water pipes. Cable and satellite system installers seem to be unaware of this and will run ground wires from their equipment, where it enters the home, to an external hose bib/water faucet. Were lightning to strike their equipment all you would have is a burst of steam throughout the home, exploded pipes, and water all over. Make them install a good earth ground or locate the service entrance ground and use it.

Our members have shown this topic can become quite complex, intense and down right intimidating. Don

A couple of things that just don't make sense. UPSs aren't recommended for A/V systems because of the ratty wave form? Who cares? Why would some one care and if they do they don't know how a UPS works. A good UPS does basically two things. It protects equipment from voltage surges both high and low as well as spikes from near by lightning strikes. You don't run your equipment off the UPS itself. During normal operation it only serves as an outlet strip with surge suppressors. The UPS only kicks in to protect the equipment in case of Low or high voltage and spikes. It's supposed to keep things running long enough to shut the equipment down properly, not support the equipment in normal operation. To repeat: In normal operation the good ones only serve as a protected outlet strip. So distortion on the output of a hi-fi set should be a non issue. Now that is the job of line conditioners, but they are normally as much as 10 times or more than the price of a good UPS because they have to protect the equipment AND produce a good sine wave output. So due to price they are not usually considered a normal way of protecting equipment.

Yes the surge suppressors and strips are a good idea IF the house has a good ground system as Icailo stated. They are also the most economical. OTOH research the net for the quality of the insurance they offer. Many have so many outs, the insurance is worthless in most cases.

The main problems that I have with UPSs are that some do not have signal line protection and that we have seen some sets that will not run on them. I suspect it has something to do with circuits like the zero crossing detect in Sony and other products, but that is just a guess. I would not assume that a UPS is protecting, you have to look at the specific specs.

As for westom's suggestions, they are basically sound, other than his claims that system local surge suppression does not work, and that signal lines do not need protection. I have seen the results of using and not using them many times in the field. I fix sets all the time with lightning damage in homes that have whole house protection with no signal line protection and/or no plug in surge suppressors. I never see damage on systems with them where all the lines are protected. His emphasis on grounding is very much correct, but there is more to the story. His vehement arguments against plug in surge suppressors and signal line protection have been debunked in other online discussions by a number of people.

The bottom line is that grounding is of primary importance, whole house protection is good, but don't forget about protecting the signal lines and system level protectors can be found very inexpensively that can be very effective. Forget about connected equipment warranties, as they are likely impossible to collect on, but make use of lifetime warranties on the surge protectors themselves. The better companies will generally honor them with few questions.

As for westom's suggestions, they are basically sound, other than his claims that system local surge suppression does not work, and that signal lines do not need protection. .
That misrepresents what was posted. I never said a plug-in protector does not work. It is not effective; a significant difference. It protects from a surge that is typically not destructive; made mostly irrelevant by protection that already exists inside appliances. Worse, even the manufacturer does not claim protection. If the manufacturer claimed that protection, then numbers could have been posted here.

Signal wires also need protection. Which is why interface chips are designed to withstand 2000 and 15000 volts. Signal protection is required and exists inside electronics.

It simply makes no sense not to use inexpensive protection that is readily available and can be installed by a user. Grounding is easy and cheap, and decent surge suppressors are also cheap. Every MOV added to a system increases the energy that can be dissipated. Contrary to what Tom says, they are not ineffective when grounding is compromised. They are less effective. They still clamp the voltage across their terminals and dissipate energy as heat.

Also, the refrain from Tom that most products contain surge suppression is simply incorrect. Most current consumer electronics products do not. Some do, but they are significantly less robust than the devices found in inexpensive surge suppressors. When they are present they are not connected to ground at all but across the hot and neutral within the device. Modern electronics ARE very insensitive to line noise, due to the conversion in the SMPS that most use. They are rather sensitive to large surges, however. I fix units damaged by them frequently. Two today, in fact.

I will say once again, grounding is the first priority, but adding surge protection that is inexpensive that covers both signal and power lines should be a consideration for anyone in an area that has significant lightning. I have seen many systems protected with no damage while nearby components with no protection were blown apart. It just makes sense to use system local suppressors that protect all lines into a system. Whole house devices are also useful, but not as effective as some suggest. It is also rare that whole house systems protect signal lines, or to have surge protection on telephone lines at the home installed by the phone company. In fact, modems are one of the most common devices damaged when lightning strikes. It is not expensive nor complicated to protect a system.

Contrary to what Tom says, they [MOVs] are not ineffective when grounding is compromised. They are less effective. They still clamp the voltage across their terminals and dissipate energy as heat.

Also, the refrain from Tom that most products contain surge suppression is simply incorrect. Most current consumer electronics products do not.
Learn from datasheets how an MOV works. Increased joules means an MOV absorbs even *less* energy. MOVs do not provide protection by absorbing surges. MOVs work by *diverting* surge energy elsewhere. Diverting is the word specifically from the NIST. If not diverted, then ineffective protection exists. From the NIST (US government research organization):
> A very important point to keep in mind is that your surge protector will
> work by diverting the surges to ground. The best surge protection in
> the world can be useless if grounding is not done properly.

Could they be blunter? Best protection in the world is useless when? MOVs do not work by absorbing surges. MOV is only as effective as the component it connect a surge to - earth ground. An MOV with more joules means that MOV absorbs even *less* energy. That is how they work. Absorb little energy; divert lots of energy harmlessly into earth.

All electronics contain protection. Some don't see an MOV. Then 'assume' no protection. For example, a 1970 standard for 120 volt electronics required protection up to 600 volts. Telephone equipment has always had a 300+ volt requirement. Intel specs require internal protection to be some of the best in a house at thousands of volts. Even dimmer switches and bathroom GFCIs contain significant internal protection. Protection defined even with numbers