Teacher
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49 Messages
Surge Protection
Do i need to run my dsl line from the wall through a power surge protector before connecting to modem
Teacher
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49 Messages
Do i need to run my dsl line from the wall through a power surge protector before connecting to modem
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Darknessrise
Professor
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2.4K Messages
8 years ago
@smwall
No, you do not. Your phone line should be grounded where it enters your residence. I know some people put surge protectors on their DSL lines, but I personally wouldn't do it. There are too many junky surge protectors out there that could reduce your DSL signal and do no good.
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Tigereyze209
Professor
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3.9K Messages
8 years ago
Actually, not only is it grounded at the point it enters your house, but is also grounded where the wire connects onto the service entrance utility pole.
And, at the neighborhood box up the road, and on, and on.. and on....
The main problem with grounding from the wall jack to the modem is, you can get a rare thing where your data signal is tottaly grounded, and you get no usable signal whatsoever.
Still though, i don't blame you for being carful.
Now, I use a very heavily rated surge supresser (not just a protector) for connecting all the power connections on my computer equipment. (A protector is mostly a breaker that trips when it detects an overload, and a supressor bleeds off the excess voltage during a power spike. Alas, does nothing for an under voltage. Once had an inverter to do that, but they are hard to find and expensive any more.)
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spoom2
Expert
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19.4K Messages
8 years ago
Seems like there’s some confusion here, there’s a difference between power grounding and surge protection and the line protection for the phone line. I’m only going to go over how the protection works on your phone line. Power surge protection, power inverters and uninterruptible power supplies (UPS) are completely different issues.
On the outside of your house is a Network Interface where the phone line comes from the phone company and from there into your home. There is a Telco side and a customer side. On the Telco side there is protection, the way it works is the phone line goes through the protection block usually gas operated. ( Back in the old days they were carbon so when they operated they stayed operated and had to be replaced, the gas operated protectors reset, so you don’t have to wait for a tech to come out and replace them.) The Network Interface is grounded and the phone line, if buried, will have the sheath also tied to the ground, the phone line itself is not grounded. If there is a surge of power that comes over the phone line than the protector will operate and throw the surge to ground, the amperage is pretty low even though the voltage rating is fairly high. So yes your phone line is protected and yes at every terminal point back to the central office the phone cables are supposed to be ground, but it’s the cable sheath that’s grounded not the lines themselves. This protects the lines in the cable from power hits either lightning or man made.
In answer to your question should you run the phone line through a surge protector, which I assume you mean the type that have a phone line in and out that you just plug the modular plugs into, than it won’t hurt, but odds you’d ever really need it are low, they work on the same principle as the Network Interface. Now your question about your DSL vs the phone line itself, they’re one in the same, the DSL signal rides the phone line, that’s why you have to filter your phone line unless there’s a filter at the Network Interface and a separate pair in a cable or a separate cable runs to where you plug your phone in.
Sorry for the length, but it’s about as short as I could make it.
Retired phone guy
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smwall
Teacher
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49 Messages
8 years ago
Thanks, How about the analog phone line...is it already grounded and also does not need to be filtered through a surge protector?
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rayman664
Contributor
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1 Message
6 years ago
A couple of months ago my house sustained a very near lightning strike and my U-verse service was knocked out. I was hoping against hope that it was only my gateway modem that was fried. That was proved false when I hooked up the replacement from AT&T and it would not connect. The AT&T tech found that the phone line connectors at the entry point into the house were charred and he had to fix that. Additional damage was that the motherboard in my desktop PC was fried, the U-Verse set-top box was fried, and the main HDMI port on my TV is no longer operable. Also , my home phone on another jack was knocked out. Pretty substantial equipment damage. So I think some kind of additional phone/Ethernet surge protection needs to be in place.
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spoom2
Expert
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19.4K Messages
6 years ago
Sounds like a direct hit on the feed to your house, which must be copper. It would be impossible over a forum like this to determine whether or not the NID was properly bonded and grounded and there are occasions when everything can be perfect yet a direct strike can still get through all the protection. From your description I doubt another surge protector on your phone line would have done any good, but again there is no way to tell. The one thing for certain about lightning damage is there's nothing for certain. I've seen cables fried to one mass of copper and I've also seen pairs in a terminal vaporized by lightning strikes. It's a massive force as I'm sure you know.
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westom
Mentor
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57 Messages
6 years ago
A solution was introduced above. Apparently you did not read it.
No surge protector does protection. Not one. A surge is an electric current that connects a cloud to earthborne charges. If that path is through (inside) your house, then damage exists. Damage that is directly and completely traceable to a homeowner. Implement protection that has been routinely implemented even 100 years ago.
That nearby strike was a direct strike - maybe incoming to all appliances. Were all appliances damaged? Of course not. To have damage, a current must have both an incoming and an outgoing path. Even a strike to wires many block away can be a direct strike incoming (directly connected) to all or many household appliances. What was the outgoing path?
If AT&T installed wires as required by codes (that existed long before you or I existed), then that AT&T wire was an outgoing path. And yes, damage is often on an outgoing path. Then many use wild speculation to assume that was an incoming path.
If any wire enters without first connecting low impedance (ie less than 10 feet) to single point earth ground, then a human created damage. How many AC wires do you have? Three? How do all three connect low impedance (ie less than 10 feet) to the same earth ground also used by AT&T? Not a rhetorical question. You are expected to inspect that (inspecting is easy for any layman) and report. Most likely, only one (or none if code violations exist) make that connection.
Any wire that enters must connect to earth. Since AT&T wires cannot connect direct, then a 'whole house' protector must be installed for free. Because every AT&T wire must connect to earth.
So why would AT&T connections suffer damage? A direct strike (that only only assumed was nearby) found a path to distant charges (maybe four miles away) through that AT&T connection. If you did not implement 'whole house' protection AND may not have single point earth ground. Critical is that connection to earth. Every connection must be low impedance (ie hardwire has no sharp bends) to single point earth ground (all four words have electrical significance).
No, this is insufficient to know what to do - the details and numbers. These only introduce concepts implemented even 100 years ago in facilities that cannot have damage. This only says enough to let you know how much to learn. And why damage is directly traceable to human mistakes. Direct lightning strikes without damage is routine for any home that implements that solution. It costs about $1 per protected appliance. With spec numbers that define protection even from direct lightning strikes. That protection remains functional for decades after many direct lightning strikes. Yes, protection from direct lightning strikes (and so many other destructive surges) is that easy.
Effective protection always answers this question. Where do hundreds of thousands of joules harmlessly dissipate. A protector is only as effective as its earth ground (wall receptacle safety ground is not earth ground).
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snstaylor
New Member
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1 Message
4 years ago
As an electrical engineer, surge protectors do work to protect your end of line equipment and I keep my DSL through one all the time. Do they always prevent damage, not in many direct strikes. Do they sometimes protect your equipment, yes for the majority of surges. They're designed to be sacrificial so eventually they will completely fail, but will most of the time save your equipment. It's my job to design power and control systems and you can guarantee they're going to be installed for discrete, analog, and power connections where you've got copper running outside underground otherwise it's just a matter of time. As an example, I would rather replace a blown surge suppressor for $50 than a $1000 PLC card. On a DSL like you will have some losses in throughput though, but it's a trade off. This is hypothetical and somewhat based on my personal connection, but what do you prefer a 13Mbps protected or 16Mbps unprotected? You choose.
Obviously most people on the forum don't understand the concept of grounding or why proper grounding helps prevent damage. Proper grounding will help, adding surge protection will add to the protection, but both will help in their own way. In residential wiring, the equipment grounding conductors are there mainly for safety allowing for a return path to the overcurrent protection in the event of a fault. This protects the individual from shock. The reason for a grounding electrode system (structure to structure) e.g. phone company, to utility, to home, etc. is to create an equipotential plane across an entire facility. This allows all equipment enclosures to rise and fall together as earth potential rises and falls with any particular surge. If potential is more equal between the two, you have a lower arc potential and thus reduce or eliminate the potential arc that could knock out equipment.
Surge protection circuits are designed to clamp or limit the peak voltages introduced by a "surge" due to lighting, poor utility, or anything else inside your home and divert the excess energy through the neutral/ground connection. I'm not going to get into theory or design, but that's all you need to know. Most will have a voltage protection rating (VPR) of about 330V for 120/240Vac, single phase systems. This means that if you do have a hurge voltage spike, your device might see up to 330V. It might survive that, and it might not. Lower spikes would be limited to lower levels. Usually 10-20% above nominal will be allowed through the device before clamping begins. I hope some of this descriptions help make your decision.
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