Lightning surge protection for dsl

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JP5

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#226133 21-Dec-2017 21:19

I live rurally an an older house and have a problem with my modems getting killed almost every time a bit of lightning goes over. I've mostly been content with just unplugging everything during storms but a few nights ago we had some weather show up suddenly in the middle of the night and after a grand total of only 2 lightning strikes (granted they were right on top of us) I'd lost another dsl modem. I want to find a solution to protect me from this but I'm not sure how to proceed and would appreciate some advice.

I do have my equipment connected to a surge protector at the power point and none of the other devices on that board (including another router) are getting fried so I'm thinking that the surge is coming down the phone line and getting to the modems thru their dsl ports. I've tried connecting the dsl thru the phone connectors on the surge protector but then I can no longer sync. The way I understand it these things aren't designed for dsl anyway and it would destabilize my connection even if I did have one that would sync. Is there some other type of surge protector that would be appropriate?

I have scouted one out at ascent: here. It has a bunch of screw terminals and isn't something I can just plug a cable into so I'm not sure how to install it. The install guide is a bit over my head. I did install my own splitter so maybe I could pull this off if anyone could give me a bit more guidance on it but I'd prefer a more user friendly solution if available.

Any advice would be appreciated.

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#1923495 22-Dec-2017 08:00

https://www.geekzone.co.nz/forums.asp?forumid=49&topicid=215269
This is what I did to stop my constant lightning fried modems, routers, motherboards etc
Got sick of disconnecting every rumble I heard.
Nothing like completely removing the issue.

I was a consultant for a WIFI distributor they sent me all sorts of stuff to write up about
Including inline RJ45 surge protectors, one needed to be wired into an earth, other just a tiny RJ45 male/female connector
Never had any faith in either.
Have a look here for examples:

https://www.megabytepcs.com/index.php?pg=product&pid=3350
or
https://www.amazon.com/Qooltek-Ethernet-Protector-Lighting-Protection/dp/B00UYXRDU8

Not sure on your phone line coming in.
A possible remedy might be earthing any unused pairs, you would need to check at both ends that they are not connected
Lightning will strike easiest path to earth

GGJohnstone

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#1923558 22-Dec-2017 09:37

Please try a pig tail of the pair wound tightly around a magnetic bar or washer. Make the winding non inductive by forming it with a loop. This will impede longitudinal current especially those of high frequency and sharp rise time. Loop current will be almost unaffected. We could argue for days as to whether lightening induction is going up or down but, what ever, this will enhance the other surge protection you might have. Direct hits will be better protected by prayer.

Oblivian

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#1923563 22-Dec-2017 09:47

If your local area is that susceptible, you're in trouble/hard to stop. I've seen outlets blown off the wall while taking out an internal protected modem (not software modem) in the old day. Even jumping the small gap the guy left the lead out with. Also tricky to tell if its coming IN, or using it as a path OUT. And starting to wire particular antennas/items etc to be earthed can quickly end as bad as licking bare cables.

Hard to stop a gazillion volts when the tree outside is zapped.

Aredwood

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#1923778 22-Dec-2017 20:39

@JP5 do you have a POTS service on the line or xDSL only? Also and or do you have a VOIP service on wired phones? What model modem do you use?

Also is the incoming line overhead or underground? Any idea if the street lines between you and the cabinet overhead or underground?

JP5

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#1923798 22-Dec-2017 21:52

I have both pots and dsl on the line, no voip. Router I use these days is a netgear dm200 just because it's the cheapest one for me to keep buying. The line goes underground into my house. I believe the only place it is exposed is at the grey chorus pillar at the bottom of my driveway (quite some distance). From there I believe it's all underground to the cabinet.

Sounds like my options are thin anyway. For the moment I think I'll try looping the pair around a washer as suggested. I might also try one of those 'lightning proof' jacks. Doubt it'll save me but worth a shot for the costs involved.

GGJohnstone

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#1923813 22-Dec-2017 23:52

Just air cores rolled up BT connector cables from Outside to Fritz and from Fritz Fon to PC where the modem used to be but is now the telephone base. I have rolled up the BT connector cable at the phone base as well.

Graeme

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Tinkerisk

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#1926376 28-Dec-2017 22:30

JP5:

Any advice would be appreciated.

Have a look for DEHN DBX series surge protectors (suitable up to f=250MHz - VDSL2 tested). This is no toy. You might need protection for the wall power outlet as well.

You could propably get them in NZ at www.vynco.co.nz

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GGJohnstone

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#1926394 28-Dec-2017 23:24

Just what you have; cables, ties and old filter adsl port is copper through.

This may slightly mask the earth lightening is seeking or enhance your equipment's existing guards.

webwat

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#1927670 1-Jan-2018 17:06

JP5:

I have both pots and dsl on the line, no voip. Router I use these days is a netgear dm200 just because it's the cheapest one for me to keep buying. The line goes underground into my house. I believe the only place it is exposed is at the grey chorus pillar at the bottom of my driveway (quite some distance). From there I believe it's all underground to the cabinet.

Sounds like my options are thin anyway. For the moment I think I'll try looping the pair around a washer as suggested. I might also try one of those 'lightning proof' jacks. Doubt it'll save me but worth a shot for the costs involved.

Shielded jacks are not lightning proof!! They just shield the cable from any nearby interference such as electrical noise from motors or fluorescent lights.

An adapter with an earth connection to leak excess voltage may help, such as your average plugin surge protector, but even a really good one will obviously not absorb a lightning strike. Having said that, any protection is better than none at all. I wonder if the soil around your place is less conductive than usual causing an "earth potential difference" between your place and the street cabinet?

Time to find a new industry!

Aredwood

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#1928025 2-Jan-2018 12:32

If the property is in a rural area. The cabinet is probably fed from a different transformer than the OPs house. And there won't be a continuous netural connection over the power network between the cabinet and the house. Which is actually the biggest factor.

hio77

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#1928044 2-Jan-2018 13:18

Aredwood: If the property is in a rural area. The cabinet is probably fed from a different transformer than the OPs house. And there won't be a continuous netural connection over the power network between the cabinet and the house. Which is actually the biggest factor.

Interesting, that certainly does add up with aggregated experience too...

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toejam316

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#1928084 2-Jan-2018 15:36

Yep - don't forget there's lightning arrestors that are earthed (unless installed incorrectly or removed by a thoughtless technician, which usually isn't the case) on most rural cabinets, to protect the equipment there, too, so the line is already earthed via arrestors at the cabinet end. Usually they don't make a lot of difference, because a lightning strike just doesn't care, however they're used just in case. You could try and setup one yourself, or look around to see if anyone is selling anything similar for the CPE side of things. Basically, the setup is a gaseous arrestor from the A-Conductor and B-Conductor to earth (usually one that breaks down around 300v) with a 6.7 ohm resistor inline with the two conductors also. You can find diagrams online.

GGJohnstone

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#1928208 2-Jan-2018 21:41

I vote for a longitudinal inductance mutually cancelling for D S L loop currents.

Induction from a clouds to ground lightening must be referenced to earth to a very large extent. Cows can die from the earth potential difference between their legs. Air to air discharge not so much loss of relative ground but never the less via the multiple earth neutral mains power reticulation and copper open wire lines cables telephone exchanges are a zeroing reference.

One customer with his telephone on top of the refrigerator had a dotted line of burn marks from the spiral cord of the handset after a storm. Phone did not care as it was a steam powered rotary dial type from before the turn of the century. At the exchange all lines had a referencing to battery ground making a collectively attractive target from the telephone on the mains earthed refrigerator.

Do not have your modem on the refrigerator. Keep it away from big ugly earths.

Aredwood

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#1928407 3-Jan-2018 11:33

@JP5 what type of house construction do you have? Raised piles with under house access or slab on ground? What type of roof do you have?

myfullflavour

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#2313578 9-Sep-2019 14:15

Got a few customers just North and South of Auckland that have been hit pretty hard by lightning strikes over the last few months.

They've got surge protectors on the AC but I'm guessing the strike is hitting the lines as well and frying the modems plugged in.

Any product recommendations that don't kill your VDSL speeds?

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