I need some help

[dar512]

TW - What's the difference between the ground wire in your basic three prong plug and the earthing thing you talk about? If a house is wired correctly, the ground wire does eventually connect up to something stuck in the ground.

[xoxoxoBruce]

TW, I bow to your superior technical knowledge but sometimes I want wring your neck. Get off your high horse and just tell me in plain English.
When I shop for a PC, how do I know what I’m getting? No, I like most people, I’m not building one. So by buying Dell’s most expensive PC, I’m safe?
My APC 500 isn’t protecting my PC from bad shit? My house system is wired properly with the 10’ copper spike to earth. What else do I need?

[Undertoad]

Anecdotal:

I installed an APC 1400 and an APC 1000 in my rack and they held up power for 5 different systems for 6 years. This included two events when power had to be generated by a portable gas generator. After 6 years one of them had a battery die. None of the systems ever had a power-related failure.

An APC 350 held up power for my main desktop but the power supply, an Antec True Power 480, seemed to develop a fault on the 12v rail. The system became unstable until the supply was changed out.

[tw]

Originally Posted by dar512

TW - What's the difference between the ground wire in your basic three prong plug and the earthing thing you talk about? If a house is wired correctly, the ground wire does eventually connect up to something stuck in the ground.

Electricity is not same at both ends of a wire. Electricity appears somewhat same at both ends of a wire in some conditions. For human safety, ground on a wall receptacle is same as the safety ground inside a breaker box. But for transistor safety, both ends of this wire are not electrically same. The technical reason is wire impedance; not to be confused with wire resistance.

Destructive surges are not stopped, blocked, or absorbed - despite what plug-in protectors would appear to claim. As Franklin demonstrated, electrical transients must be shunted (redirected, diverted) to earth ground. For Franklin lightning rods, a connection to earth must be short, no splices, no sharp bends, not inside metallic conduit, etc.

Surge protector does same; shunts transients to earth. During a surge, a protector is but a wire. Connection from each AC electric wire to earth ground must be short, no splices, no sharp bends, etc. Protector makes that connection IF protector is properly earthed.

'Whole house' protectors are effective when connected less than 10 feet to earth ground. 'Whole house' protectors from responsible manufacturers such as Square D, Cutler-Hammer, Siemens, Intermatic, Leviton, and GE are installed at the service entrance. Earth ground wire from that mains breaker box to earth must be 'less than 10 feet', no spliced, no sharp bends, not inside conduit, and separated from non-earthing wires. Requirements that both meet and exceed post 1990 National Electrical Code (NEC) requirements.

Note manufacturer names specifically not mentioned: APC, Tripplite, Belkin. Products have no earth ground connection AND they avoid this discussion. Instead, they promote sound bytes and 'word association' as a replacement for good science and the all so critical earth ground.

Return to that equipment ground at a wall receptacle. That equipment ground wire is bundled with other non-earthing wires. It has numerous sharp bends. Too many splice. Far more than 10 feet from the earth ground rod. In short, a wall receptacle equipment ground, obviously, is not an earth ground. No earth ground means no effective protection.

[tw]

Originally Posted by xoxoxoBruce

My APC 500 isn’t protecting my PC from bad shit? My house system is wired properly with the 10’ copper spike to earth. What else do I need?

Your APC does not even claim to protect from the typically destructive transient. They use classic propaganda techniques so that you will assume such protection. The APC UPS does one function - battery backup of data during blackouts and extreme brownouts.

Listed were protectors that can make that 'less than 10 foot' earthing connection. More responsible retailers such as Home Depot (Intermatic) and Lowes (GE and Cutler-Hammer) sell these solutions. Also most electrical supply houses. Never saw an effective protector sold in Radio Shack, Kmart, Sears, Staples, WalMart, Office Max, Best Buy, Circuit City, or Target.

Meanwhile, 'whole house' protectors are so effective and so inexpensive as to be provided, free, by the telephone company in your NID. This, too, will only be as effective as the earth ground 'you' have provided. CATV wire requires (and best has) no surge protector. Protection is provided by a hardwire connection from cable ground block to, again, the common point earth ground.

All incoming utilities (including satellite dish) must enter at the same location to make that 'less than 10 foot' connection. Otherwise a building's earth ground must be enhanced as demonstrated by Cinergy in this figure of wrong, right, and preferred earthing:
http://www.cinergy.com/surge/ttip08.htm

Notice what defines protection: earthing. Pictures demonstrate what Orange County did to correct frequent surge problems - it's all about shunting to earth as Franklin demonstrated in 1752:
http://www.psihq.com/AllCopper.htm

[dar512]

Thanks, tw. At least now I know.

I'm in an older home, though, and that sounds like a lot of electrical work to add after the fact.

[Undertoad]

How could one possibly know whether Comcast grounded their box correctly?

[xoxoxoBruce]

Holy Shit! In Florida they had to sink the ground rod 120 feet!!!

[tw]

Originally Posted by Undertoad

How could one possibly know whether Comcast grounded their box correctly?

I once sat for coffee with two Comcast installers who had just returned from training on this subject. Previously, no cable installers (apparently) had any idea what earthing (a 1930 technology) was about. As I explained these various points to them, the one kept saying, "So that is what they meant" and "So that is why we are suppose to do that". Like electricians, these concepts were completely foreign to most all installers.

The ground block on a cable wire is shown below. From this ground block (that is sometimes inside a gray box that had nothing but this ground block), a 10 AWG wire connects to an earth ground that you (the homeowner) must provide. If you did not provide this common earthing point, then Comcast, et al may install something inferior.

That earth ground, at minimum, must be a 10 foot copper clad rod (sold in any Home Depot or Lowes for about $10). Too often electricians or installers will even cut an 8 foot rod in half. That four foot rod is woefully insufficient earthing. A rod that is not solidly in earth (can be removed) is also disconnected from earth. Earthing concepts well proven before WWII and now made essential for every home are too often compromised by those who never learned how and why.

(BTW, those three light ground testers report nothing about earth ground.)

One rod is a major earthing improvement. Anything additional provides exponentially decreasing improvement. That Orange County Emergency Response center must be so reliable as to spend $thousands more on a 120 foot ground rod just to make the last 0.1% of lightning totally irrelevant. But a residential owner must, at minimum, install that earth ground rod with a 6 AWG bare copper wire that connects less than 10 feet to breaker box.

We have now identified both ends of the cable earthing wire. Returning to those Comcast installers' questions: let's say a cable connects only to a second floor TV. So they attach cable at second floor level, and then run an earthing wire from that cable down to an earth ground rod. They have just made that TV a target for damage. Incoming cable wire must attach at second floor level, drop down close to the common earthing electrode, make a less than 10 foot earthing connection, then rise up (separated from the 'drop down' wire) to attach to that second floor TV. Cable must attach short to earth ground before entering a building AND must separate its 'before earthing' section from 'after earthing' section. The 'less than 10 foot' rule is essential.

That wire from ground block to earthing electrode must have no sharp bends, no splices, must remain separated from all other earthing wires until they all meet at the earth ground, AND must remain completely separated from non-earthing wires. Too many installers want to make things neat. They nylon ty-wrap (bundle) wires together and make neat sharp bends. An old rule: neat often means an inferior installation. Neat can also make induced transient damage likely.

Pre-1990 buildings use water pipe as earth ground. No longer acceptable and not sufficient. Quality of an earth ground is not just in better conductivity. Distance from each incoming utility wire to that common earth ground is most important. That every incoming utility connects to the same earthing electrode is essential. Yes, that means even a satellite dish cable or TV antenna must first connect to earth ground before entering.

This is a ground block that would be inside that Comcast gray box. Earthing wire (often gray or green but in this case black) connects to this ground block:

[Elspode]

Originally Posted by xoxoxoBruce

Holy Shit! In Florida they had to sink the ground rod 120 feet!!!

Isn't that about 95 feet into the water table down there?

[Undertoad]

Since my cable installer did nothing of the sort, my best bet is to throw Comcast out and tell the satellite installers how to do their business.

[xoxoxoBruce]

My cable comes down the pole and enters a watertight thermocouple head on a plastic pipe, 4 ft up the pole, then comes 40 ft under ground into the cellar. Then it travels 8 ft, makes a 90 and travels 3 ft to the grounding block before splitting into three legs. The wire from the ground block is a straight 18 ft run to the service entrance ground at the breaker box.
Doesn't sound like much lightning protection.
Oh well, maybe the lightning will fall off the drip loop at the thermocouple head.

[tw]

Originally Posted by xoxoxoBruce

The wire from the ground block is a straight 18 ft run to the service entrance ground at the breaker box.

18 ft wire is cable company just barely meeting NEC requirements for human safety. If concerned for household transistor safety, then utilize a solution demonstrated by Cinergy in their 'bad, good, and preferred' pictures cited earlier.

Even underground wires provide no transistor protection. Even underground wires must be 'surge protected' by connecting to a common earth ground point at the service entrance.

Above posts define secondary protection. Inspection of the primary protection system also may be necessary:
http://www.tvtower.com/fpl.html

Curious. How many actually know what a drip loop is?

[Clodfobble]

Originally Posted by tw

If a power supply does not cost $65 full retail, then it is probably missing essential functions and therefore can contribute to motherboard damage. So let's see. We save $15 on an inferior power supply. Then must buy a $100 UPS to correct the power supply defect? I see this reasoning routinely where people buy on price rather than learn simple technical concepts.

That's nice, but you left out the part where for the second and third computers we bought high-end, non-Asian-market surge protectors, and they also didn't work. Or perhaps you were speaking hypothetically?

[eiffelenator]

Dang this thread has been a great read.
props, TW!