lightning and surge protection

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Stevenfyeager

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United States, Indiana
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electrical contractor
My customer wants lightning and surge protection for his home electronics. (computer) He asked me if a whole house type or single outlet is best? I personally have no knowledge of what to suggest we do for him. Any advice ? Thank you.
 
Most of the "single outlet" and power strip stuff sold is almost worthless. They likely work, but only once because the devices they use on small inexpensive units are basically sacrificial during an event powerful enough to worry about in the first place.

I always recommend that if it's worth doing, it's worth doing right, so a "whole house" system installed on the service panel. I also recommend using one from a known reputable company and one that includes an "event counter" to let you know when it has taken a lot of hits and should probably be replaced, and a set of LEDs that will let you know when it has failed and MUST be replaced. Personally, I like the GE Tranquel line, and the Eaton SPD line.
http://www.eaton.com/Eaton/Products...ndMonitoring/SurgeProtectiveDevices/index.htm
https://www.geindustrial.com/products/surge-protective-devices
 
For best protection install a whole house surge protector in the main panel, the largest you can get. For additional protection, use power strips with built-in surge protectors or UPS's which also have built-in surge protection.

Then check the lights on the surge protectors on a regular schedule (weekly, monthly) to verify they are still working.
 
The research I have done suggests that cascaded protection is best. Whole-house protection at the main service for protection from the outside world, and point-of-use protection at sensitive equipment for protection from internal sources.
 
Jraef said:
Most of the "single outlet" and power strip stuff sold is almost worthless. They likely work, but only once because the devices they use on small inexpensive units are basically sacrificial during an event powerful enough to worry about in the first place.

I always recommend that if it's worth doing, it's worth doing right, so a "whole house" system installed on the service panel. I also recommend using one from a known reputable company and one that includes an "event counter" to let you know when it has taken a lot of hits and should probably be replaced, and a set of LEDs that will let you know when it has failed and MUST be replaced. Personally, I like the GE Tranquel line, and the Eaton SPD line.
http://www.eaton.com/Eaton/Products...ndMonitoring/SurgeProtectiveDevices/index.htm
https://www.geindustrial.com/products/surge-protective-devices
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Not something that is common here but on some of our exported systems we fitted Metal Oxide Varistors (MOVs)
 
cots is ez, APC makes some ok ones that can take a hit, and they usually have a little "ok" light. they also come with insurance coverage.

for places where i can install my own, i use Littlefuse
http://www.littelfuse.com/~/media/e...ittelfuse_varistor_ultramov_datasheet.pdf.pdf

i usually parallel a few of the biggest ones i can fit (using the correct voltage and clamp ratings), i usually put them in a small Hammond case and then fill with an epoxy, via pigtail the attach to the line voltage to protect the device. as example, inside a computer case, or inside hvac unit. you could technically make one that has cap cord on one side and a single receptacle on the other.

but for a customer, cots, APC
 
LarryFine said:
The research I have done suggests that cascaded protection is best. Whole-house protection at the main service for protection from the outside world, and point-of-use protection at sensitive equipment for protection from internal sources.
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I agree with Larry on this. Surge protectors are like shock absorbers in your car. If you didn’t have them you would feel every bump, no matter how small. Using the cascaded approach will give you some added protection in the event that some of the power surge gets by the protection at the breaker panel. You don’t necessarily have to buy the most expensive devices on the market but I would use the higher end ones over the cheap and dirty ones.

I currently use the Sycom Surge units and have not experienced any problems with them. However, if you get a direct lightning hit I believe you can kiss it all goodby.:cool:
 
There seems to be a basic misunderstanding of how surge protection works.

For one thing, NOTHING will protect your precious stuff from a direct lightning strike. That is why you have home owner's insurance.

Surge protection kicks in to protect your stuff from voltage transients that exceed what is supposed to be on your power lines, at whatever point that might be.

Surge protection devices are like switches that come on and short out the voltage transients when they exceed a certain level. This protects your stuff that is downstream from the SPD from transients that are above the voltage level that the SPD turns on at.

A typical whole house SPD installed at the service equipment will not turn on until the incoming voltage exceeds something like 500 V for a 240V rated device. So you still have some potential for downstream damage from transients that are not shorted out because the voltage is not high enough to trigger the protective action. These kind of SPD generally can dissipate quite a bit of energy without failing.

SPD installed closer to point of use generally have lower voltage trigger points and can dissipate less energy. But because you have a higher rated SPD upstream, the downstream SPD don't have to take on the higher energy transients.

These days most electronic devices except for pure junk are pretty well protected already against the lower levels of transients that are likely to be seen at point of use. Power supplies these days are pretty robust so offer a lot of protection from low level transients. If the power supply can take the transient hit, nothing downstream of it is going to be damaged. It is not perfect but it is a lot better than what we had ten or twenty years ago.

BTW, be extremely suspicious of any SPD seller who is claiming "lightning" protection. if they really believe that they are pretty much clueless and there is no reason to believe anything they tell you about surge protection in general.
 
post #10, i suspect OP's cust is asking about the surges that come from nearby lighting strikes or induced lightining transients. one doesnt even need lightning, switching in/out a cap bank will cause transients.

but surely, no spd or stuff connected to it will survive a direct hit by lightning.
 
LPS and SP...two different things that work in complimentary ways. I'm an expert in neither, but only know the concept. LPS is designed to literally shunt a strike that would have otherwise hit the house...to ground. Obviously, everything won't get shunted as there are all sorts of other electromagnetic stuff happening where coupling occurs. This is where the SP systems pick up what's left. Whatever is left that gets to the panel is picked up by the panel SP. If you have individual units at components, they are the third line. All said, there can be events that get through all three with sufficient destructive power to fry electronics.

LPS involves installing lightning rods at locations on and around the house. This is for the experts that know what they are doing...know where to put them to cover the house...to insure any strike that would have hit the house hits the rod instead.

Panel SP are still very good all alone. They will work on surges that occur due to lightning events that occur close by and sends charge through the POCO lines. This is not technically lightning protection. It is surge protection due to lightning (and other events that cause surges). And if you think about it, the large majority of events will be surges...not direct lightning strikes on the house. But if LPS is truly needed/desired, hire someone who specializes in the work.
 
lightning and surge protection

I always recommend panel-mount surge as well as receptacle surge protection; I do custom homes and price this in as a standard. I typically just use the square D surgebreaker in conjunction with P&S surge protected receps at every TV & electronics location; the receps have an alarm built-in to notify of a failure.

During a storm last year, an REA primary line landed on top of a customer’s GA Power primary line; it took out both surgebreakers, half of the surge receps, and about 30 AFCI’s, but they didn’t lose a single TV or electronic device.

Also, pretty much all whole-home SPD’s I’ve installed require additional surge protection at the receptacle for warranty coverage.

Edit to add...: I also install coax and telecom surge protection for cable & phone.


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In my neck of the woods, the local POCO (REMC) locates an SPD right on the transformer can and places another under the meter.

No charge for the transformer SPD but they do charge for the meter SPD which has led's and a sound announcer to indicate if non-functional.

On top of that they recommend panel level SPD's and a host of point of use devices.
 
JPinVA said:
LPS involves installing lightning rods at locations on and around the house. This is for the experts that know what they are doing...know where to put them to cover the house...to insure any strike that would have hit the house hits the rod instead.
Click to expand...
I'm not an LPS expert, but I'm pretty sure that lightning rods are there to dissipate charge differential before it gets to the point where a strike happens rather than to attract a strike. I don't think that the conductors that connect lightning rods to a ground rod are anywhere nearly large enough to handle the current in a typical lightning strike.
 
LarryFine said:
Correctamundo, and the sharper the point, the better.
Click to expand...

Yes. The shorter the radius of curvature over the tip of the lightning rod the tighter the electric field gradient. In the presence of a charge differential you want the gradient to be so tight that the dielectric (capacitance) of the air is broken down and charge can escape. Extreme occurrences of this can cause the air to glow round the tips of lightning rods, sometimes called St. Elmo's Fire.
 
Ok I can sum up pretty much all the responses with a quote from Mike Holt
1. You get what you pay for
2. More is better

I install control systems, have about 40 sites, services from 60 amp to 600 amp. Once I started installing SPDs about 25 years ago, we stop losing power supplies.
For the smaller services I use Leviton 42120-001 120/240. For three phase 480, its a 42277-DY3 on the primary and a 42120-001 on the secondard. All of these have alarm contacts and audible alarms. I have had two fail, from overvoltage from car pole accidents. These SPDs are about $350

For 300-600 amp services we use a Levition 52000 series, these guys have replaceable modules and feed thru wiring, IE hit the bus with your branch circuit, in and out, keeps the impedance down

Leviton does make some less expensive units for homes.

One more comment, the lead length to the SPD is critical. The levition units have 18" leads, zipped tied together. Install the SPD directly opposite the branch circuit breaker, with not slack in the leads
 
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