Surge protecting ethernet powerlines and rj45 to rj11

[attacus]

Currently I have an ethernet cable running from my router to a powerline plugged into a 1 way surge protector. For some reason surge protected power strips rarely come with a rj45 in/out, and it's always limited to 1.

I wanted a more elegant solution and thought of either getting a laptop surge protector which comes with network ports, or plugging a rj11 to rj45 cable from my router into the modem port on my main surge protected strip, then plugging that into my powerline.

What are the drawbacks in terms of speed? I hear it will be limited to 10/100 mbps which I can live with. It's just for the upstairs console.

 

[bill001g]

You do not want to plug the powerline devices into any form of surge protector they pretty much need to be plugged directly into the wall. If you plug them into surge protection many times it filters the data signal the devices create. They many times do not work at all when you plug them into surge protection. You just have to take the risk with these devices. It is extremely rare to hear about one being damaged.

Ethernet ports by design have built in surge protection. There are small transformers on every pair of wires so they are magnetically isolated from the other circuits in the end device. Some devices also have optical isolators. There should be no way for a surge to get past the end device and into the ethernet cable.

 

[attacus]

You do not want to plug the powerline devices into any form of surge protector they pretty much need to be plugged directly into the wall. If you plug them into surge protection many times it filters the data signal the devices create. They many times do not work at all when you plug them into surge protection. You just have to take the risk with these devices. It is extremely rare to hear about one being damaged.

Ethernet ports by design have built in surge protection. There are small transformers on every pair of wires so they are magnetically isolated from the other circuits in the end device. Some devices also have optical isolators. There should be no way for a surge to get past the end device and into the ethernet cable.

I'm not too concerned about the powerline. My worry is that a powerful enough surge could go through the wall and the powerline and damage the router, and everything attached to it. If you're saying ethernet ports have built in surge protection, why are there network protectors on some surge strips? Also, does that apply to all ethernet ports, cheap and expensive, old and new?

 

[bill001g]

The surge protection is pretty much just a by product of how ethernet works. Ethernet is designed to run a very long distance and its uses extremely small difference in the voltage between the pairs to encode the data. Because the equipment on either end may have very slight difference in power and this power can vary a little even during normal operation they had to find a way to solve that. They decided to use very small transformers.

There are a bunch of other parts before the transformers that would likely be blown out well before it got anywhere near the ethernet.

Even in a router or any other equipment that has external power bricks it is unlikely a surge would pass though the power brick and damage the router. Most time it is the power brick that would be fried.

A ethenret cable is even further removed from the power.....even PoE ports have requirement to keep the power isolated.

Company will sell things to anyone who they think they can con into buying it. I have seen ones claim they protect fiber optic cable from surges. I would laugh at a person who used one of those.

Things like cable or phone lines that come in from outside the house to a point you can worry about surges because you may get a lightning strike nearby. That is the reason building codes require you to ground these as the enter the building which should dissipate any power. You would need a very strong lightning strike to come into your house for a surge protector to do any good. Ethernet cables are seldom run outside the house so lightning would have to already be inside and I would not be worrying about my equipment at that point.

 

[attacus]

The surge protection is pretty much just a by product of how ethernet works. Ethernet is designed to run a very long distance and its uses extremely small difference in the voltage between the pairs to encode the data. Because the equipment on either end may have very slight difference in power and this power can vary a little even during normal operation they had to find a way to solve that. They decided to use very small transformers.

There are a bunch of other parts before the transformers that would likely be blown out well before it got anywhere near the ethernet.

Even in a router or any other equipment that has external power bricks it is unlikely a surge would pass though the power brick and damage the router. Most time it is the power brick that would be fried.

A ethenret cable is even further removed from the power.....even PoE ports have requirement to keep the power isolated.

Company will sell things to anyone who they think they can con into buying it. I have seen ones claim they protect fiber optic cable from surges. I would laugh at a person who used one of those.

Things like cable or phone lines that come in from outside the house to a point you can worry about surges because you may get a lightning strike nearby. That is the reason building codes require you to ground these as the enter the building which should dissipate any power. You would need a very strong lightning strike to come into your house for a surge protector to do any good. Ethernet cables are seldom run outside the house so lightning would have to already be inside and I would not be worrying about my equipment at that point.

Thanks for the advice. I've adjusted my setup accordingly. However I was wondering what the dangers of an unprotected phone line were during a power surge or lightning strike. Does it damage just the phone (or modem), which I can live with, or can a shock spread to anything nearby ?

 

[bill001g]

Phone lines are not connected to the power.....they work really good even when the power is out.

If you got a directly lightning strike that somehow not absorbed by the grounding as it enters the house you might blow the modem but like ethernet DSL ports are isolated from the rest of the modem. You get a big enough strike and it will pass though anything....it goes though the air so nothing can really stop it.

 

[westom]

However I was wondering what the dangers of an unprotected phone line were during a power surge or lightning strike. Does it damage just the phone (or modem), which I can live with, or can a shock spread to anything nearby ?

First understand why things get damaged. A direct strike to AC utility wires (underground or overhead) far down the street is a direct strike incoming to everything inside the house. Is everything damage? Of course not. It is electricity. To be damaged, the item must have both an incoming path and another outgoing path to earth.

Once inside, a surge hunts for an appliance(s) that makes a best connection to earth - destructively.

Best protection on phone lines and cable is the earth ground - discussed earlier. But not just any earth ground. It must be single point earth ground. That means every wire inside every incoming cable (cable TV, phone, satellite dish, AC electric) must make a low impedance (ie less than 3 meter) connection to earth. The concept is called equipotential.

If any wire violates that requirement, then a surge enters on that wire, goes through the appliance, then is outgoing to earth on one other wire.

For example, a surge incoming on AC electric can pass through a TV, outgoing destructively via the HDMI port and then to earth on the cable TV coax. In this case, damage is often on the outgoing path - HDMI port. And not on the incoming path - AC electric.

Same applies to a router's power brick. To be damaged, a surge must be incoming on AC mains and outgoing to the router. Both incoming and outgoing paths must exist. That surge is in everything from AC mains to earth. But only one items in that current path typically fails - in this example the power brick.

More often a surge passing through ethernet, router, and power brick damages the ethernet port; not its power brick and other parts of a router. Remember, it is electricity meaning an always existing incoming and a completely different outgoing path exist - simultaneously..

Surges can be hundreds of thousands of joules. Many want to block or absorb that surge with a magic box that is only hundreds of joules - ie a interior protector. Will its 2 cm part stop what three kilometers of sky could not? Or course not. Will its near zero joules absorb a destructive surge - tens or hundreds of thousands of joules? Of course not.

Protection is not about a protector. Protection is always about the one item that harmlessly absorbs hundreds of thousands of joules - single point earth ground.

Best protection for cable is a hardwire from that coax ground block, connected low impedance (ie hardwire has no sharp bends), to single point earth ground. Then a destructive surge harmlessly dissipates outside.

Neither phone nor AC electric can connect directly via a hardwire. So a protector does what that hardwire does better. An effective protector always has a dedicate wire to connect low impedance (ie less than 3 meters, not inside metallic conduit, no splices, etc) to single point ground. Then a surge will not hunt for earth destructively via any ethernet devices. Then a surge is not even incoming to the router - or any other appliance including the dishwasher, furnace, RCDs, clocks, radios, recharging phone, etc.

Each protection layer is only defined by what absorbs hundreds of thousands of joules. That is not an adjacent protector. Only earth ground defines each protection layer.

This is how it was done even 100 years ago. So well proven that damage is considered a human mistake. Protection (earth ground) is an 'art'. If a surge does damage, the homeowner then starts with his earth ground to discover where he made a mistake; for example where a wire enters the building without first connecting low impedance to single point earth ground.