Anything at all to be done about surges from lightning?

Razer

Razer

Pulling my weight
Apr 1, 2014
320
161
Midwest
I lose quite a few cameras to lightning, and switches too for that matter. Is there anything good that can be done to isolate these surges better? I've tried cat5 surge arrestors that are like rack mount devices but they have been less than successful. Many times when cameras would have issues the fix was to bypass the surge arrestor and it would work fine. It was very hit and miss for reliability and was the first thing to mess with if a camera went down.

A strike will hit the property gate quite often for example, then travel to the gate system, to the switch, then out to cameras killing them. ACTi cameras die the easiest and I'm moving away from them for that reason, but there still have to be a better solution. Electrician(s) have grounded the gate and such and checked the electrical, good grounds on all equipment and still cameras will get hit. I know at one location we've added at least 4 more ground rods at various areas. This is an issue at a few areas that super lightning prone for whatever reason, the vast majority have never lost a single camera in years. It's either property on an Indian burial ground, or its built over something like a silver or gold vein lol. Maybe I should check into that.... :rolleyes:

Anyway, any arrestors that work without breaking the bank? I would need 40 cameras covered at various locations right off the bat just to test.
 
Thanks, I had seen them bot not tried either one yet. I purchased 20 of the APC ones and will try those out, and I know for a fact I'll know if they work here soon as these locations are hit more than once a year....
 
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A short gap using fiber optic cable could prevent surges from going down the ethernet. Might still go down the electric wire that the fiber media converters are plugged in to though.
 
We got hit hard with lighting, lost a lot of equipment but lighting hit an underground cable between two big switches and ouch. Good to see they have something for it. I'll bring it up and see if they want to spend the money on them as lighting is rare for us, this was the first time in the 30+ years I've lived here.
 
Razer said:
Thanks, I had seen them bot not tried either one yet. I purchased 20 of the APC ones and will try those out, and I know for a fact I'll know if they work here soon as these locations are hit more than once a year....
Click to expand...
How did they work out? @Razer
 
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I find all this quite confusing and apologize for writing a somewhat lengthy post.

I do not know how it is in other countries but for the mains power, we have here in Sweden five conductors:

Phase L
Phase M
Phase N
Zero
Protection ground

I assume that this is pretty much standard everywhere. For connection of protection ground in rural areas, we have two typical schemes:


  1. You make a solid protection ground using a copper rod or copper wire in the ground near the house. The protection ground is then tied to the potential at the location of the house, whereas the the three phases are tied to the ground at the transformer, which could be a mile away and have a potential thousands of volts different from that of the protection ground.
  2. A cheaper but often used solution is to make a local protection ground by simply connecting the zero and the protection ground together at the point of entry to the building. The entire installation is then floating together with the potential of the transformer at some distance from the house. That is what I have in my house.

To protect Ethernet cables coming from other buildings, you can get protection devices like these already mentioned in previous posts:
http://www.amazon.com/exec/obidos/ASIN/B008060BU0/ref=nosim/ipctk-20
http://www.amazon.com/gp/product/B0...de_a_smtd&showDetailTechData=1#technical-data

They require a good ground and will then tie the Ethernet cable to ground and short-circuit transients between the individual cores of the Ethernet cable.

In my system, the switch, router, fiber modem, ip phone adapter and the 12 power supply are floating and have no ground. I do not understand to what extent the BI computer is floating. If I would use one of the listed protection devices, I would then tie the ethernet cable to some ground. Should that be the mains protection ground or a copper rod in the ground outside the house? It seems to me that it should be the mains protection ground? Or, since the switch anyway is floating, would it make more sense to use the protection device to suppress voltage spikes between the Cat5e cores and forget about the ground connection?

Does one also need protection at each IP cam in the adjacent building? That might require a lot of grounding wire.

Sorry if I am not crystal clear but I find this confusing. The best would obviously be to use fibers.
 
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@t_anderson: This thread is 1.5 years old, so the people who were originally following it may not be around or paying attention anymore.

That said, in the US (except for certain special applications) most places use three conductors for 110-120V (standard for small appliances):
Hot/Live/Phase
Neutral/"Return" (connected to Earth at only one point, the electrical service panel)
Ground (should generally only carry a signal in case of device failure)

I think the primary benefit of these surge suppressors is to prevent current from a lightning strike that hit nearby and traveled through the ground from entering the buried ethernet cable and damaging the devices connected to it, so it'd really only make sense to put one on the outside of a building after the cable leaves the ground (i'm not sure if it'd be appropriate to use one on each end of the cable or not). For devices with no cable going under ground, these surge suppressors will provide little or no benefit, since the charge is unlikely to enter through a cable running along a wall above ground. For protection against direct hits above ground (particularly on a roof), it's better to get a lightning protection system installed.
 
Good points, Benjamin. Then you use the same mains wiring principles with five conductors in the US as we have here in Sweden.

My worry is not so much that the lightning actually jumps through the insulation into the Ethernet cable from other installations or a direct hit. If that happens, then I believe that all hope is out and we can go out and buy new equipment in any case. I think that many of us have seen that with soot on the cables.

I am more worried that when the lightning hits a tree or something not too far away, then there is such a huge electrical field around the house that any conductor will act as an antenna picking up transients with voltage spikes of thousands of volts. In other words, just the existence of a long conductor in the system is enough to pick up a transient that can kill the system. That’s what I believe happened once when my computer and most equipment died. That is also why use of shielded cables makes sense (although I haven’t done it).

I also suspect that merely running an Ethernet cable along mains cables over a certain distance is a bad idea. It may be enough to create voltage spikes in the cable by induction.

So to me, the issue is that when you have an antenna picking up a transient, you can use a surge protector to short-circuit the transient to ground. The problem is then to decide which “ground” to use and in which end of the antenna (or both). When the lightning hits, there are voltage differences everywhere, indoors and outdoors.
 
There are two main types of surge arresters: MOV and gas tube

MOVs look like round flat disks, like a disc capacitor. They are used in all the cheap $5 "surge protector" power strips. They have high resistance until a certain voltage is crossed and then they flip to full conducting. They seem to wear out after a while from absorbing small spikes, but will "look" brand new yet, so are not the greatest.

Gas tube arresters looks like a round tube fuse with two or three contacts (one in center of the tube). These tend to last much longer than MOVs. The better grade devices allow you to easily replace the gas tube when a large surge blows it up. Phone company hardware has a standardized plugin gas tube module.

If you want better quality arresters you will look for gas tube explicitly in the name of the device. Expect to shell out some bucks for this.


Here for example is what I'd consider a quality design. 4 gas tubes, in a single ethernet CAT6 arrester, with outdoor mounting case and cable grommet to keep out dust and insects.

http://www.l-com.com/surge-protecto...-cat6-gas-tube-lightning-protector-rj45-jacks

kFmWG1M.png



Indoor rack mount 12 device gas tube arrester:
http://www.l-com.com/patch-panel-se...base-t-gas-tube-cat6-lightning-protector-rj45

($260 / 12 = $21 per protected device. Individual protection modules can be replaced if they get nailed)
 
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randyth said:
Unfortunately I live in an area where short blackouts and power surges can occur.

At the moment I'm using this Forza Regulator (which supposedly also has protection against surges):

http://www.forzaups.com/us/products.../forza-avr-1200va-600w8-out-110v-black-3-leds

I'm thinking about switching to an UPS though (more reliable and provides some uptime during a blackout). I'm still looking for a good deal
Click to expand...

I am using this UPS:
http://www.amazon.co.uk/APC-Back-UP...UTF8&qid=1459360201&sr=1-1&keywords=cs500+ups
I am quite happy with it, it's cheap, it can send an e-mail, when there is a blackout, and it can turn off the computer gracefully. It's fairly old technology though, and it does not protect the ethernet lines, which I believe is the toughest part...
 
Javik said:
There are two main types of surge arresters: MOV and gas tube

MOVs look like round flat disks, like a disc capacitor. They are used in all the cheap $5 "surge protector" power strips. They have high resistance until a certain voltage is crossed and then they flip to full conducting. They seem to wear out after a while from absorbing small spikes, but will "look" brand new yet, so are not the greatest.

Gas tube arresters looks like a round tube fuse with two or three contacts (one in center of the tube). These tend to last much longer than MOVs. The better grade devices allow you to easily replace the gas tube when a large surge blows it up. Phone company hardware has a standardized plugin gas tube module.

If you want better quality arresters you will look for gas tube explicitly in the name of the device. Expect to shell out some bucks for this.


Here for example is what I'd consider a quality design. 4 gas tubes, in a single ethernet CAT6 arrester, with outdoor mounting case and cable grommet to keep out dust and insects.

http://www.l-com.com/surge-protecto...-cat6-gas-tube-lightning-protector-rj45-jacks

kFmWG1M.png



Indoor rack mount 12 device gas tube arrester:
http://www.l-com.com/patch-panel-se...base-t-gas-tube-cat6-lightning-protector-rj45

($260 / 12 = $21 per protected device. Individual protection modules can be replaced if they get nailed)
Click to expand...


I just ordered a couple of these cheap protectors:
http://www.ebay.com/itm/221463578455
I want to take a look at them and see if I can use them. It looks as if they use two gas tubes. What are the other components? Zener diodes?
Maybe they do not protect the POE lines, but if one uses separate power injectors that should not be as much of an issue? I also wonder whether they reduce the bandwidth.
I can report back when I have received them.
 

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I have now received the surge suppressors that each cost $ 6.39 incl. shipping from China. The build quality is very good, no cheap plastic or anything like it. The diagram is shown in the sketch below. The differential voltage is clamped to max appr. 15 V using fast overvoltage suppressors (similar to zener/avalanche diodes). The input voltage with respect to ground is clamped using gas discharge tubes. I do not know what the clamping voltage relative to ground is but the Ethernet input stage is usually quite tolerant to changes in common-mode voltages, so that should probably not be a problem. It will only work up to 100 Mbps.

All in all this looks like a good product (haven't had a chance to test it in the system yet). The main issue is that it only has pass-through for pins 1,2,3 and 6, so it won't handle POE. For those who use separate POE injector/splitters it may not necessarily be an issue if one can protect the power supply separately in some way. In any case the output impedance of the power supply should be fairly low so small voltage peaks may not pose much of a threat.

I only wish that they would make these in batteries with, say, 8 lines at a similar low price.

Correction: The gas discharge tubes are of type Epsine 90 14, not as shown in the diagram

IMG.jpg
 
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Javik said:
Here for example is what I'd consider a quality design. 4 gas tubes, in a single ethernet CAT6 arrester, with outdoor mounting case and cable grommet to keep out dust and insects.

http://www.l-com.com/surge-protecto...-cat6-gas-tube-lightning-protector-rj45-jacks


Indoor rack mount 12 device gas tube arrester:
http://www.l-com.com/patch-panel-se...base-t-gas-tube-cat6-lightning-protector-rj45

($260 / 12 = $21 per protected device. Individual protection modules can be replaced if they get nailed)
Click to expand...

I like the L-Com products and have been using them for a few years now. Their quality has always been excellent.
 
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