DIY surge protection...

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Doug White wrote:

Earthing electrodes are connected to the neutral in the meter enclosure? Not the most common practice. (If that is the connection, it removes one of my comments on the suppressor at the meter.)
The breaker panel, I assume, has the service disconnect. That means the neutral and ground are bonded together at that point and it is the 'ground reference point' for the power system. The phone and cable entry protectors should be connected to the earthing electrode wire that connects to the meter. You want the length of the ground wire from phone/cable entry protectors to the common connection with the power system earthing to be short. You also want the distance from that common connection point to the power ground reference point (in the service panel) to be short. Yours is lengthened by the length of neutral from the panel to the meter. If there is a large surge current from power wires to earth, that raises the voltage between power and phone/cable wires. If that is a concern, there are some service panel suppressors that have ports for phone and cable wires to go through (SquareD makes one).
--
bud--




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It depends on the utility. Either is acceptable to the NEC, and the distance between the meter and the service panel should be short.
Delta Lighting Arrestors are one common brand, trivial to install.
http://www.deltala.com /
You can have both an arrestor and a capacitor if you like. Look for LA302R and CA302R if searching the web. The surge capacitor helps the surge arrestor, at some additional cost. They also make larger/industrial units, though doubling up residential units seems to get more bang for the buck than swapping a "residential" for an "industrial", at least at the 120/240 single-phase service point. Keeping the leads as short as possible when installing them on the panel will help them work better.
Several of the panel makers (eg, Square D) have come up with in-panel units that plug in like a dual pole breaker, but they cost more. In theory, they might work better due to less lead inductance as they are plugged right into the bus bars. In practice, they have lower ratings than Delta arrestors available for half the price, probably because they have to fit into the space alloted to two breakers.
--
Cats, coffee, chocolate...vices to live by

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Ecnerwal wrote:

Even though short, it adds to the length to the common connection point and thus adds to the voltage between power and phone/cable wires. Wire inductance (which you mention) makes the voltage higher that what it would seem. The voltage could be damaging to equipment connected to both power and phone/cable - like TVs. The NIST guide suggests that much of the surge damage may be caused by high voltage between power and signal wires. For the ground wire from a phone entry protector, 10 feet may be too long.

As far as I could see none of the devices were UL listed. That would disqualify their use for me. I also didn't see any that said they met appropriate IEEE standards for protection.
The voltage limiting in over 90% of power circuit suppressors uses MOVs. Would be nice to see someone independent evaluate Delta's use of silicon oxide varistors. Their comparisons are to arc-gap arresters, which are common on circuits over 1000V. (Current use of "arrester" in the NEC is for circuits over 1000V.)

I have not seen any source that recommends using surge capacitors on wiring below 1000V. And recommendations were for a surge cap with an arc-gap arrester.
MOVs are fast enough to not need a capacitor. (Looks like Delta's arresters are too.)

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The web site leaves something to be desired. I ordered mine, and in fact the surge capacitors have the end-user UL mark, and the surge arrestors have the UL component mark. Both are the dual Canada/US marking.
The surge capacitor has the additional function/labeling of a facility EMI filter, which seems logical.
I suspect the component, rather than end-user, mark on the arrestors is because they are supposed to be installed inside a box to prevent any problems if they get more surge than they can arrest, and disintegrate. They certainly pass inspections on a regular basis.
--
Cats, coffee, chocolate...vices to live by

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I have a few whole-house (well, whole branch circuit) UL-rated surge arrestors. They are big (4" long by 2.25" diameter) plastic cans that attach to the main breaker box, and are wired into the branch circuits that they protect. The cans cost something like $50 each from the local electrical supply house, and are made by an outfit in Texas. I have a pair of their Model 302 arrestors.
<http://www.deltala.com/prod02.htm
The website doesn't work right for Safari or Firefox in MacOS, so it's probably MSIE only. But you can make it work anyway, with fiddling and indirection.

They are not just capacitors, they are industrial-size metal-oxide varistors plus capacitors.

No.
Probably ferrite EMI-supression "beads", which have no effect on computer-smoking surges. Yes, it's hot+return.
Joe Gwinn
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On Sat, 20 Mar 2010 11:47:51 -0400, "Existential Angst"

Someone needs to alert the Darwin Awards - Looks like we may have a last minute entry!
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Existential Angst wrote:

Hi, Whoa! At last EA is showing his true intelligence exposing his level of ignorance. 'nuff said.
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On Sat, 20 Mar 2010 11:47:51 -0400, "Existential Angst"

Here's a very good document on home protection written for the non-electrically inclined-
http://www.lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf
Pay particular attention to the section on GPR, there's a lot of people in the industry who, while they may know about it "intellectually", don't really think about it enough. :(
Suppressors don't just protect against lightening but also against transient spikes on the power lines induced by heavy equipment etc.
How much protection you get depends on how much money you spend. The cheaper MOV "little black box" units that Mr. Holme's electrician is so in love with (he does do neat wiring, though :)) are good for the occasional spike, if you live in an area prone to lightening & you own a lot of $$$ electronics you might want fork out for an industrial strength unit-
http://www.transtector.com/ProductData?class ph
but figure on ~$1000 for a top of the line one with SASD devices that will stand up to the abuse.
H..
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On Sat, 20 Mar 2010 11:47:51 -0400, "Existential Angst"

A surge protecter/surge suppressor is one thing. http://en.wikipedia.org/wiki/Surge_protector http://www.elect-spec.com/faqspike.htm Spikes might be another.
Beware induced spikes on phone & data lines.
--
Cliff



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wrote:

Ferrite rings are for EMI, so the buzz in the box stays there and not in your radio or stereo. Switching power supplies can generate a whole lot of hash and that's the type that's gradually replacing the old-syle wall warts. The ring is acting as a choke for RF, also generated by the computer itself. Different deal than surge protection, but also needed these days.
Look up "surgistor" or MOV, that's what's in those surge protectors. They're rated in joules, the amount of energy they can pass. The higher, the better, and more costly they get. The better surge protector strips will say how much energy they can handle on the package. I assume the panel versions do the same. What none of the ad copy says is that MOVs have a distinct lifespan. They WILL wear out after snubbing "x" number of spikes and become useless. Some of the power strip units tie the neon switch light to the MOVs. If no light when switched on, the MOVs have expired and it's time for a new strip. But nobody tells the consumer about it. So there's a whole lot of dead protectors out there that are just power strips now. Usually there's MOVs between ground and each supply wire and between the supply wires. Not rocket science.
As far as lightning protection, they'll do part of that, up to the energy rating. Which is why you need the tiered approach. Arrestors on the line in, surge protectors on the panel and on each high-value electronic item. My sister is always getting hits, they blow the phones off the walls, but since she's gotten decent surge protectors, those get fried instead of the computer or video equipment. They have to be replaced, but she gets the sort with insurance attached, so not that costly.
There are other approaches to surge and spike protection, an MG set is pretty much immune to any such up to direct lightning strikes. A ferro-resonant transformer used to be a big part of the innards of one line of power conditioners, pretty much immune to spikes, but the transformer itself was noisier than a whole switch yard. Had one in a corner of the shop for a mini-computer, had to go outside to talk to anyone. None of those will snub spikes on LAN, phone or video cables, for that you have to go to power strips with built-in protection or stand-alones.
Stan
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On Mar 21, 12:41 pm, snipped-for-privacy@prolynx.com wrote:

In professional papers, tiering is not about protectors. Tiering is about the only system component that dissipates the energy. Every protection layer is defined by that component ALWAYS required in each protection layer - the single point earth ground. The only item that dissipates that energy. Every protection tier is defined only by the earth ground. Any protector without earthing does not tiering.
A residential 'whole house' protector is discussed. But that entire protection layer is defined by what the protector connects to - earth ground. Homeowners should also inspect their 'primary' surge protection system. That is the other protection layer: http://www.tvtower.com/fpl.html
Protectors that do not even claim protection in their numeric specs (ie that Belkin) will not discuss earthing. They hope you assume a protector magically makes energy disappear. The NIST (US government research agency) citation provided by Bud is quite blunt about what an effective protector must do:

What happens if the protector does not make that short (ie 'less than 10 foot') connection to earth? That energy must dissipate somewhere? Buds IEEE citation page 42 Figure 8 shows where that energy dissipates: 8000 volts destructively via nearby appliances. Either that energy is earthed. Or that energy will hunt for earth ground inside the building destructively via appliances. Both IEEE and NIST make that point.
I am being kind. I have only called them ineffective. NIST is blunter about what a protector without earthing does:

See those pictures of the Belkin posted elsewhere? It even threatened human life. And the NIST also describes plug-in protectors are >useless<:

Only more responsible companies sell effective protectors. With an always required, dedicated wire to make a short connection to earth. Responsible companies including General Electric, Leviton, Intermatic, Siemens, Square D, and even the Cutler-Hammer solution that sells in Lowes and Home Depot for less than $50. In every case, an effective protector has a wire to dissipate energy harmlessly into earth. Plug- in protectors do not are not part of a tiered solution. Without earthing (ie plug-in protectors), "The best surge protection in the world can be useless if grounding is not done properly." Could they be any blunter? Protection is always about where energy dissipates. Each protection layer is defined by what provides protection the single point earth ground.
Secondary protection is earthing at the service entrance. Primary protection is earthing by the utility. Each protection layer is about where energy dissipates not by some high profit box that somehow makes energy magically disappear.
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westom wrote:

From surge expert Martzloff: "Whole house protection consists of a protective device at the service entrance complemented by [plug-in surge suppressors] for sensitive appliances [electronic equipment] within the house." Kinda sounds like tiering to me.

Complete nonsense.

Because anyone with minimal intelligence can read in the IEEE guide that plug-in suppressors do not work primarily by earthing.

Only magic if your religious blinders prevent you from understanding how suppressors work.
The NIST (US government

Ho-hum. w just repeats the same distortions. Repeating: What does the NIST guide really say about plug-in suppressors? They are "the easiest solution". And "one effective solution is to have the consumer install" a multiport plug-in suppressor.

The lie repeated.

Ho hum - 3rd repetition. Repeating: Being responsible companies, all these manufacturers (except SquareD) sell includes plug-in suppressors. And the $50 devices do not meet w's minimum specs.

Martzloff says they are: "Whole house protection consists of a protective device at the service entrance complemented by [plug-in surge suppressors] for sensitive [electronic equipment] within the house."

And the required religious mantra. Still not explained - why aren't airplanes crashing daily when they get hit by lightning (or do they drag an earthing chain)?
Still no link to another lunatic that agrees that plug-in suppressors are NOT effective.
Still never answered - simple questions: - Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors? - Why does the NIST guide says plug-in suppressors are "the easiest solution"? - Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"? - Why do your favorite manufacturers make plug-in suppressors? - Why does favorite manufacturer SquareD say (for their service panel suppressor) "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
--
bud--

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snipped-for-privacy@prolynx.com wrote:

There is (in the US) apparently no definition for how joules are measured. As a result, some manufacturers measure jules in a deceptive manner, which puts honest manufacturers at a disadvantage. As a result, some good manufacturers are not providing joule ratings anymore. Instead they give surge current ratings (which are comparable).
The IEEE guide warns against comparing devices based on joule ratings unless the test method is the same. Too bad - I like joule ratings.

Certainly can happen.
In my first post I quoted an investigation by Martzloff that found only about 35J max at a plug-in suppressor with even the strongest surge that can be reasonably expected on power wires. One reason is arc-over at the service panel. The other is the impedance of branch circuit wiring. Both are mentioned in other posts. If the branch circuit is very short - outlet under the panel, the energy can be higher.
I recently bought a major brand plug-in suppressor (about $30) with ratings of 590J and 30,000A per MOV, 1770J and 90,000A total. I don't expect the suppressor will ever fail. The manufacturer apparently doesn't either - there is a connected equipment warranty.
The current ratings, 30,000A, are in some ways odd - there is no way you could get that current to the suppressor. It is higher than what will come in on the service. But the high current ratings go along with the high joule ratings.
The joule rating for a MOV is the single event energy hit the MOV can take and be at the defined end of life (but still functional). If you look at MOV ratings curves, you find that if the individual energy hits are a small fraction of the rated energy, the cumulative energy rating is far higher than the single event rating. If my 590J MOVs only see 35J or far less events, the cumulative energy rating will be far over 590J - another reason for connected equipment warranties.
High ratings are useful in the same way for service panel suppressors.

The normal failure mode for MOVs is to start to conduct at lower voltages until they conduct at normal voltages and have thermal runaway. Any suppressor you buy in the US should be listed under the appropriate UL listing - 1449. UL1449 has required, since 1998, a thermal disconnect for overheating MOVs.
For plug-in suppressors, the IEEE guide goes on at length about how the protected load can be connected across the MOVs, and be disconnected when they fail, or can be connected across the incoming line. In the former case, the load is 'protected' even if the MOV fails. Another reason why manufacturers can have protected equipment warranties.

A good idea, particularly in high risk areas. It is suggested by Martzloff in another post. Plug-in suppressors are particularly useful if the protected equipment has both power and phone/cable connections - equipment that is particularly at risk.
Note that all interconnected equipment has to be connected to the same plug-in suppressor and external wires (including phone and cable) have to go through the suppressor. I think this is not as well understood as it should be.
The max probable current on hot service wires is 10,000A. Service panel suppressors with much higher ratings are readily available.

Phones off the wall sounds odd. I would look at the phone entrance protector and length of ground wires from phone and cable entrance protectors to the ground at the power service. The entrance protector and earthing should protect the phone (using US installation practice). And look at earthing system?

All good information. Never been around a ferro-resonant transformer - interesting.
--
bud--

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I have designed EMP protection for missile silos. I have designed lightning protection for aircraft. I have designed surge protection for aircraft.
I have not designed surge protection for households.
But once in a start up, I was testing the upper limit of the input Voltage range for the switching powers supply I had designed for an ultrasound cart. I used a surge protector power strip as an extension chord. I dialed up up the 60Hz AC to a couple hundred VAC.
If the surge protector worked for a while, I don't know. But the stink of the smoke that came out of that surge protector had to be smelled to be believed.
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On Mar 22, 11:28am, " snipped-for-privacy@gmail.com"

You needed a protector with larger smoke packets. Yours ran out too soon!
Paul
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