Even code says that earth ground must exist. From FCC Part
68.215d(4):
From the National Electrical Code Article 800.30:
Your telco may only earth to provide human safety. To also provide transistor safety, that earthing must meet and exceed post 1990 earthing requirements. Some of those additional requirements were provided previously: 'less than 10 foot', separated from other non- grounding wires (ie safety ground inside Romex cable is not earth ground), no splices, no sharp bends, etc. Violating these earthing requirements means a surge may seek earth ground, destructively, via household appliances (ie modem, answering machine, portable phone base station).
Appalling are the large number of Americans who don't know how electricity works. Talking to the telco phone banks is like asking an English major why a light bulb works. They don't know. Only way to get problems solved is to get the lineman - the only telco service people who know how electricity works. You can spend hours explaining the problem to a phone droid. The lineman takes a look and solves it in minutes.
This problem is so acute that Verizon recently created a VP of customer service.
If you did not have earthing, then you had no surge protection. AND if all incoming utilities are not earthed to the same point (directly or via a protector), then damage will still result. Nobody is 'required' to solve surge damage due to multiple earth ground rods. However one utility discusses the problem AND solutions in "Preventing Damage Due to Ground Potential Difference" at:
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Bottom line: you (the homeowner) is responsible for providing proper earthing. If you don't provide sufficient earthing, then inadequate earthing by each utility may be installed. Any utility wire in any cable that enters without a connection to earth ground can earth lightning, destructively, through appliances. One common path to earth is incoming on AC hot (black) wires, and destructively to earth via telephone appliances and that telco installed 'whole house' protector. All incoming wires must connect to that same earthing electrode - the single point earth ground.
This is America. The homeowner is ultimately responsible for getting all utilities to properly earth. How good is that earthing (meaning how good is that protection)? Well, what single point earthing electrode(s) did you install?
As others have stated, the telco protector has to be grounded to work. It sounds like you have a grounding issue.
The way these things work, is that when the voltage reaches a certain level then the device shorts to ground. Earlier devices use carbon blocks with an air gap between them. This limited the voltage exposure to 1000 volts which was adequate for rotary phones but not necessary for modern electronics. The next generation used gas tubes which provide better protection (around 365V, if I remember correctly). The following generation used solid state devices which provided even better protection.
The question is what do you have. Depends on the age of your installation. If you still have carbon blocks, I would see if the telco would upgrade your protector. If you have a network interface then you probably have gas tubes or solid state which is the best the telco will supply.
As for the suggestion of making your own protector. I believe that the ring voltage is 220 volts. I would not use 160V MOV as someone suggested. There are companies that make telco protectors. Most use cheap MOVs. If you can find one with solid state device which react quicker, it would offer better protection but at a higher cost.
Part of the problem is tthat device manufacturers often do not realize the voltages that can occur on telephone lines. The cheaper equipment manufacturers often use components that cannot withstand these voltages. It is easy to blame the teleco but the reality is that the current generation protector offer the best protection while allowing the network to work. I admit I am bias since I used to work for the group that designed these protectors.
Code says the second ground rod must be located at least 6 feet away.
As long as a wire from NID (demarc) to earth ground rod is sufficient gauge (14 or 10 AWG), then increasing wire gauge does little to create better earthing. Again, the word is impedance. Thicker wire means lower resistance; not lower impedance. Lower impedance is more important. Lower impedance is best created by making that earthing connection shorter, no sharp bends, no splices, etc. Increasing wire gauge provides minimal if any significant improvement. Shorter wire length is more important than a thicker wire.
Better protection means a shorter connection to earth and a longer distance to the protected appliance.
Correct. First multiple, separate ground rods make telephone appliance damage easier. Second, multiple, separate ground rods violate National Electrical Code.
If the first ground rod is ok and about 8 feet long, it will do almost no good to install a second ground one or two feet away. I think the code is 6 feet and maybe a #6 wire. Anyway no mater what the code, the rods need to be atleast 6 feet apart to get the benifit out of two rods. The rods need to be installed almost as far apart as they are long.
I have a rural house that suffered several modem failures from lightning surges also. I got the same story when I asked them to check the grounding. They said it was properly grounded at their junction box. Problem was the junction box was 635' from my residence. I drove a 10' ground rod adjacent to the demarc box on my residence and connected it directly to their ground terminal. Haven't lost a modem or phone since. Some battles are just not worth fighting!
MOV = Metal Oxide Varistor A varistor is a resistor with a resistance that is not constant.
If you know what a Zener diode is, a MOV is like a bidirectional Zener diode.
A MOV tries to limit the voltage across it. As surge voltage rises above a characteristic clamp voltage rating, the current rises very rapidly. That can result in thousands of amps through the device (for a very short time). Most surge suppressors are based on MOVs because MOVs have high current and high energy dissipation ratings in a small package, and they are cheap.
(Clamp voltage) times (current) times( time) equals energy that is absorbed by the MOV as heat. That can produce some damage.
MOVs have an energy rating, which is the max energy the MOV can absorb in a single event. After that, they will still function but with further hits will degrade.
If the single event energy rating is far above the actual energy hits, the cumulative energy rating is far higher than the single event rating. With high ratings a plug?in suppressor is not likely to fail.
A wire has resistance and inductance. At power line frequencies the inductance can generally be ignored.
Surges are very short duration events. That means they are high frequency events. Wire inductance can not be ignored, and is more important than resistance in determining the impedance of the wire.
The impedance of the ?ground? wire in a branch circuit limits the effectiveness of a plug-in suppressor for earthing a surge. But the IEEE guide explains plug?in suppressors do not work primarily by earthing a surge.
But impedance of branch circuit wires also greatly limits the surge current (and thus energy) that can reach a plug-in suppressor.
Review and post that UPS numeric specifications. It does not claim to provide protection. It does protect from a type of surge that typically does not cause damage. Spec probably provides only one number - total number of joules.
That joules numbers says how tiny the protector circuit is and does not even say where those protector circuits are located. That protector circuit is something above zero. Sufficient to claim surge protection in color glossy brochures. But so near zero as to virtually not exist.
Again, your telco installs a 'whole house' telephone line protector for free. How good is this protector? How good and how close was earth ground that you provided? If that telco 'installed for free' protector is close (ie less than 10 feet) to the same earthing electrode used by AC electric, cable, and satellite dish, then some of the best phone line protection already exists.
What does any shunt mode protector do - that telco protector, MOV, Gas Discharge Tube (GDT)?
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Section 6.4: WHEN SHOULD YOU WORRY ABOUT LIGHTNING?
What does an effective protection system have? A 'whole house' protector and a short connection to earth ground.
Protectors do not stop or absorb what three miles of sky could not stop. Ineffective protectors claim to absorb (stop) surges. Effective protectors clamp that surge energy harmlessly into earth.
A protector without a dedicated earthing connection (ie that UPS) will not divert (shunt, connect, clamp, conduct) energy. Surge energy may then find earth ground destructively via household appliances. The surge permitted inside a building finds and harms appliances that will earth that surge. Either a surge is earthed before entering the building ('whole house' protector or a hardwired connection), or that surge will seek earth ground destructively inside a building.
So again, what is claimed in UPS numeric specs. Do they list each type of surge and protection from that surge? Of do they just give a joules numbers (required by standards) and claim no protection? The effective protector has a dedicated wire for that short connection to earth.
The 'top of the front page' articles in Electrical Engineering Times were entitled "Protecting Electrical Devices from Lightning Transients". Low wire impedance is defined and required for better surge protection at:
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What undermines a protector? Earthing wire that is too long, sharp bends, splices, inside metallic conduit, bundled with other non- grounding wires, and not using a single point earth ground. Many of those compromising installation mistakes increase wire impedance. Effective protection requires a low impedance connection to earth. Protection can be supplemented by increasing impedance between protector and electronics. 50 foot of romex between the 'whole house' protector and an appliance means even better appliance protection. That distance, all those sharp bends, multiple splices, etc increase wire impedance.
. Service panel suppressors are a good idea. What does the NIST guide say? "Q - Will a surge protector installed at the service entrance be sufficient for the whole house? A - There are two answers to than question: Yes for one-link appliances [electronic equipment], No for two-link appliances [equipment connected to power AND phone or cable or....]. Since most homes today have some kind of two-link appliances, the prudent answer to the question would be NO - but that does not mean that a surge protector installed at the service entrance is useless." .
. I have only seen w_ talk about "stopping" or "absorbing".
The IEEE guide explains plug-in suppressors work primarily by CLAMPING (limiting) the voltage on all wires to the common ground at the suppressor. .
. A UPS may or may not have effective protection. High ratings are more readily available in plug-in suppressors. .
. "Each type of surge" is nonsense. Plug-in suppressors have MOVs from H-N, H-G, N-G. That is all possible combinations and all possible surges.
Still missing - a source that agrees with him that plug-in suppressors do NOT work.
Still missing - answers to embarrassing questions:
- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?
- Why does the NIST guide says plug-in suppressors are "the easiest solution"? ? Why does the IEEE guide say (for long phone entrance ground) "the only effective way of protecting the equipment is to use a multiport [plug-in] protector".
Funny. That surge energy clamped on all wires goes where? Nowhere. According to Bud, that surge energy disappears because wires are clamped together. But then the IEEE guide Page 42 Figure 8 shows what happens when surge energy is not clamped to earth. That surge energy finds another path to earth - 8000 volts destructively - through the adjacent TV.
Bud once claimed surges were absorbed by plug-in protectors. That spin did not work. So now he does not make that claim.
As Bud notes, the UPS surge protector circuit is grossly undersized. Sufficient to claim surge protection on color glossy brochures. Too woefully undersized (near zero) to provide any real surge protection. However, UPS for surge protection is promoted to those who 'know without first learning'. Appreciate how many do this. Appreciate how many recommend a UPS for surge protection because they only read the color glossy brochure - and ignored numbers in the manufacturer's spec sheets.
Which protector by itself provides effective protection? Well, the complete protection system from any plug-in protector would be defined in its numeric spec sheets. Oh. No plug-in protector lists each type of surge and protection from that surge. Where is this protection? Manufacturer cannot claim protection when a connection to what provides protection - earth ground - does not exist. A protector is only as effective as what provides protection - what dissipated surge energy: earth ground. No dedicated earth connection means no effective protection. No wonder that plug-in protector does not claim protection in its numeric spec sheets.
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