On Jul 22, 3:51 pm, westom <[email protected]> wrote: > On Jul 22, 2:03 pm, Doug Brown <[email protected]> wrote: > > > Clearly one of the issues is the age of the house and utilities not > > bringing their ground systems up to spec. The house was built in 1960 > > and has 2 prong wiring; that responsibility is on me but unless I win > > the lottery I can't afford to rewire the house right now.
I am surprised there are not ground conductors from 1960. If it was wired with metal sheathed wiring, the sheath was considered to be a grounding conductor (which you probably know) Ground conductors can be added to existing receptacles and run back to a code specified source. It is often as easy to fish a new wiring run. I would particularly want grounds to computers and expensive entertainment centers. If you are using a plug-in suppressor, it should be on a grounded circuit. The NEC allows using a grounding type GFCI receptacle on ungrounded wiring. Although still not grounded, the GFCI adds a lot of protection. And grounding type outlets can be used on ungrounded wiring if protected by a GFCI. It is hard to imagine your phone service does not have a protector/NID that is earthed. Phone companies have been very good about installing them. Cable companies often aren't so good. And the record for satellite dishes is even worse (although they don't have the same high- current exposure). > > Both of Bud's citations make that point. For example, Figure 8 on > page 47 of: > http://www.google.com/url?sa=D&q=http://www.mikeholt.com/files/PDF/&u... > A plug-in protector has no earth ground. So it earths energy > destructively via an adjacent TV. 8000 volts destructively. Anyone can read the IEEE surge guide and see what it says in this example (pdf page 42): - A plug-in suppressor protects the TV connected to it. - "To protect TV2, a second multiport protector located at TV2 is required." - the point of the illustration. - In the example a surge comes in on a cable service with the ground wire from cable entry ground block to the ground at the power service that is far too long. In that case the IEEE guide says "the only effective way of protecting the equipment is to use a multiport [plug- in] protector." - It is simply a lie that the plug-in suppressor in the IEEE example damages the second TV. - westom says only service panel suppressors are effective. In this case a service panel suppressor would provide absolutely *no* protection because the surge is coming in on the cable service. That is also apparently the case in Doug's case, where it appears the problem is an unprotected phone service. (But power service suppressors are a good idea.) Contrary to what westom claims, the IEEE guide says plug-in suppressors are effective. The only 2 examples of protection (at the end) use plug-in suppressors. > > Bud's NIST citation says the same thing: What does the NIST surge guide really say about plug-in suppressors? They are "the easiest solution". And "one effective solution is to have the consumer install" a multiport plug-in suppressor. > Plug-in protector numeric specs confirm this. No plug- > in protector numeric spec claims protection. Specs are readily available. A 10 year old could find them. Some suppressors even have a protected equipment warranty. > > Bud's job is to promote plug-in protectors. To quote westom "It is an old political trick. When facts cannot be challenged technically, then attack the messenger." My only association with surge protectors is I have some. westom has a religious belief (immune from challenge) that surge protection must directly use earthing. Thus in his view plug-in suppressors (which are not well earthed) can not possibly work. The IEEE guide explains plug-in suppressors work by CLAMPING (limiting) the voltage on all wires (signal and power) to the common ground at the suppressor. The voltage between the wires going to the protected equipment is safe for the protected equipment. Plug-in suppressors do not work primarily by earthing (or stopping or absorbing). The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40). westom is evangelical in his beliefs. He uses google-groups to search for "surge" to spread his message that plug-in suppressors do not work. Some of what he says is very good. Everything he says about plug- in suppressors is nonsense. > > Bud claims that energy just magically disappears. I have explained numerous times where the energy goes. If there is no service panel suppressor, when the voltage from the busbars to the enclosure reaches about 6,000V there is arc-over to the enclosure. After the arc is established the voltage is hundreds of volts. Since the enclosure is connected to the earthing electrode, this dumps most of the surge energy to earth. Since the neutral is bonded to the enclosure and "ground" at the service the exposure of house wiring is much more limited than would be expected. This greatly limits the energy that can reach a plug-in suppressor. Another limit is the impedance of the branch circuit. Since a surge is a very short event, it is a relatively high frequency event. The impedance of the branch circuit greatly limits the amount of energy that can reach a plug-in suppressor. The NIST surge guru, who also wrote the NIST surge guide, investigated the amount of energy dissipated in a MOV in a plug-in suppressor. With surges up to the maximum that has any reasonable probability of occurring on power service wires (10,000A), and branch circuits 30 feet and longer, the maximum energy was a surprising 35 Joules. In 13 of 15 cases it was 1 Joule or less. > In every case, > protection means upgrading earth so that protectors make a short > ('less than 10 foot') low impedance connection to that single point > ground. The NIST guru on surges, has written "the impedance of the grounding system to `true earth' is far less important than the integrity of the bonding of the various parts of the grounding system." That is, make sure all incoming wires - phone, cable, satellite dish, ... - have their entry protector connected with a *short* wire to the earthing system at the power service. This is a true single point ground. Then improve the earthing system if you want to. Good protection for hams does the same thing. All the wires entering the shack have their voltage clamped to a ground buss, which is then earthed (in addition to other earthing). Hams with big antennas can have significant probability of a direct lighting strike - with much higher currents than will come in on utility wires. Imagine a surge causes a current to earth of 1,000A, and the resistance to earth is a quite good 10 ohms. The building system "ground" will be 10,000V above "absolute" earth potential. If the service protectors are connected with short ground wires all the wiring floats up together. If there is strong current to earth, different points on Doug's ground ring may be at far different voltages. (Lightning rods are required to protect buildings from direct lightning strikes.) > A protector is only as effective as its earth ground. westom's religious mantra. Why aren't airplanes crashing every day when they get hit by lightning - or do they drag an earthing chain? As explained by the IEEE, plug-in suppressors work primarily by clamping, not earthing. For real science read the IEEE and NIST surge guides - excellent information. Then read westom's sources that say plug-in suppressors are NOT effective. There are none. He is also unable to answer simple 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 NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug- in] protector"? - Why do your "responsible manufacturers" make plug-in suppressors? - Why does "responsible" manufacturer SquareD says "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"? -- bud-- -- You received this message because you are subscribed to the Google Groups "The Unique Geek" group. To post to this group, send email to [email protected]. 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