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How to prevent electrical spikes coming in through the telephone line

Posted on 2016-08-05
Last Modified: 2016-08-09
My house or area is prone to lightning strikes.  About a year ago my BT router blew after a lightning strike, and the spike coming into the router preceeded to blow the network card from the PC that was connected to it via ethernet.

Fast forward to last month, another thunder storm, and my replacement BT router has blew again.  This time, the network card in my PC was fine, however the network card in my Synology NAS blew, as did a standard home telephone, and the base station for another cordless phone that I had.  Nightmare.

The old "you must switch off the devices when there is a thunderstorm" advice is no good, because for start it's 2016!  Also, I'm at work for 8 hours a day, and asleep for another 8.  So I need some sort of protection from this.

Can you recommend anything?  I've had a look at an APC device, but this is RJ45 rather than RJ11 so I don't know if it's suitable.  Also, some reviewers online report that this thing actually reduces their broadband bandwidth, which of course I'd like to avoid like the plague since we're not on fibre broadband here yet.

I don't understand why these things are not more prevalent to be honest.

Any advice would be appreciated.

Question by:meirionwyllt
LVL 35

Expert Comment

ID: 41744037
APC has been the leading UPS company the past decades, and they include the phone jack in most consumer products.


(Yes, it's RJ11, and it's to protect it, why otherwise built-in an incoming and outgoing port?)

You saw RJ45 in the server products, but that's not for protection, that's for management (since it was only one port, not incoming AND outgoing)

Author Comment

ID: 41744049
Hi Kimputer,

Is that link for an UPS?  I'm not looking for an UPS only surge protection for the phone line.
LVL 35

Assisted Solution

Kimputer earned 76 total points
ID: 41744064
Yes, it is a UPS. I know you want surge protection, I just assumed there was budget for a superior product (and have extra functionality then just surge prot).

Here is the surge only product:

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LVL 14

Accepted Solution

Don Thomson earned 120 total points
ID: 41744149
While battery backup (UPS) are fine  for protecting you from brownouts and total loss of power, a decent power bar will normally have the two RJ11 jacks on it  that allow you to protect your hardwired analog line from power surges coming in through your local phone line. Some of these actually come with a warranty that will pay for any damage to properly connected devices.  The phone line should have a "Protector" located at the entrance to your house.  These are essentially two pieces of flat carbon that have a very small space between them that wil arc in the presence of higher voltages,that will take the wires and apply a "Ground" to the circuit.  These are normally installed when ANY portion of the cables coming from the Central Office of the phone company to you location are not underground but are still on poles.  Call your telephone service provider and ask them to check your service and verify that there are Protectors installed on your line.

The regular power bars that are available may protect against high voltage spikes but not all can handle the power of lightning.  Make sure before you buy one.
LVL 14

Assisted Solution

by:Joseph Hornsey
Joseph Hornsey earned 76 total points
ID: 41744194
I concur... APC is the way to go and you can just use a surge protector rather than a UPS.  Keep in mind RJ11 plugs will fit in RJ45 jacks, so even if it's RJ45, it'll still work.
LVL 28

Assisted Solution

jhyiesla earned 76 total points
ID: 41744470
Something else you may want to consider is outfitting your home with lightning rods. Now if the strike is coming in from the power pole or telephone pole - if you have those in your area, this may be a waste of time, but if the lightning is going for you home, this would potentially route it away and into the ground without affecting things in your home. Check with someone in your area who could help you with this.
LVL 12

Assisted Solution

by:Bryant Schaper
Bryant Schaper earned 76 total points
ID: 41744568
APC as well, check out Protectnet line, cheap and if this is a business the rack mount chassis is cheap too, we protect our equipment using the analog cards, coax and serial cards.  

LVL 83

Assisted Solution

by:Dave Baldwin
Dave Baldwin earned 76 total points
ID: 41744739
I agree about asking the phone company to check the 'protectors' on your phone line.  Those should be your first line of lightning protection and if they are already blown, they need to be replaced.  One other thing... if the lightning is too close and the spike is too high, nothing will protect you.  Nobody has invented anything that will protect against a direct hit, it's just too much power.

Author Comment

ID: 41748359
Thanks very much for your advice - a lot of useful info on here.

I was thinking of buying one of these, which I'm guessing is the UK version of the PRO7T mentioned above http://www.ebuyer.com/734481-apc-surgearrest-performance-surge-protector-ac-230-v-8-output-connector-s-white-pmf83vt-uk

I will inquire about lightning rods too.

Also I'm glad to hear that there might be something that my telephone service provider could do to help here as regards protectors on the line, and I will definitely chase them up on this.  If that conversation leads anywhere I will post updates here.


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