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Question Modem surge protection - RJ11 line-in or RJ45 line out?

HappySailor

Junior Member
Sep 24, 2020
3
1
36
Toasted!

For the 2nd time in a year, a lightning burned our router, amongst other devices.

We know that nothing can stop a lightning, but we want to protect as much as possible our equipment.

Lightnings come into the rack from the phone lines as we have surge protectors on the electricity lines, plus multiple UPSs with stabilizers.

As we have multiple VDSL lines (100Mb/s), we're wondering if it is better to protect line-in to the modem (RJ11) , risking a signal degradation or go for an Ethernet RJ45 surge protector on the modem output?

Any brand/model suggestion? We need 5.
 
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SamirD

Golden Member
Jun 12, 2019
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www.huntsvillecarscene.com
Bummer. :(

It really depends on if you care about the modems burning out. If you don't, just the ethernet will work, but otherwise you can get a block installed for the phone lines and add filters as well.

But they don't always help. In the hotel industry we had multi-line pbx systems that were blown out all sorts of ways. Initially it was via phone lines so we added the block. Then it was via power surges so we added a panamax surge suppressor (UPSes were too expensive back then and not enough va). And then finally we had a lightning strike across that street that traveled up the dedicated ground for the system and went backwards through the system getting stopped at the power supply fuse. That same lightning strike took out our fire alarm system, our phone system, part of our property management system, one washer, one dryer and our big sign. Total damage was over $40k in a split second--and the insurance company denied the claim. :eek: It was a bad year...
 

HappySailor

Junior Member
Sep 24, 2020
3
1
36
Thanks, Samir.

Modems are the last problem. So you confirm that it would be wiser to work on the Ethernet side to avoid spoiling the so-sensitive VDSL signal?

Is there any reliable brand/model?
 

Jimminy

Member
May 19, 2020
33
10
41
Thanks, Samir.

Modems are the last problem. So you confirm that it would be wiser to work on the Ethernet side to avoid spoiling the so-sensitive VDSL signal?

Is there any reliable brand/model?
I have found nothing works better than physically unplugging equipment during thunderstorms. Even strokes only nearby can induce huge voltage spikes and produce damage. Direct hits ALWAYS do ... no protection ever for that.

I don't have a real fancy super setup, but here's what I do ... I unplug the ethernet cable and power cable from my satellite dish modem. I leave the coax cable connected as it would require a wrench to disconnect. I unplug one heavy AC power cord connecting all my computer equipment from the 120 V electrical line.

I also have a fencer (they pulse the pasture electric fences with 10-15 KV pulses to keep animals from escaping). I unplug it. Also, the fence line leading in has a knife switch. I throw the blade to disconnected position (very important). This way, all but a direct hit will be diverted through the gas discharge tube on the fence lines.

It works because I am usually present, and know if storms are approaching. If I leave for a day or two and think a storm may blow through, I leave with everything shut down. It's a pain, but the best way if you live where storms blow in.
 
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SamirD

Golden Member
Jun 12, 2019
1,122
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www.huntsvillecarscene.com
Thanks, Samir.

Modems are the last problem. So you confirm that it would be wiser to work on the Ethernet side to avoid spoiling the so-sensitive VDSL signal?

Is there any reliable brand/model?
Yeah if the modem can be sacrificed it's actually nice as it's one more piece of equipment that can die and stop the flow. I haven't really found anything that seems decent except these by APC:

Looks like they make something else too that is even rackable:
 
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