Grounding

This is for you electrical engineers:
I live in San Antonio and install alarm systems. We used to drive ground rounds, but not anymore. We are now told to go to the nearest cold water
(copper) pipe for our ground. Problem is sometimes our panels still show ground faults. Many times, while on the phone with tech support, we are told to cut the ground wire and it will also, sometimes, actually fix the fault. I was told by two manufacturers that no ground is better than a 'bad' ground.
Anyone willing to help me understand this?
Also, have one large building always getting pelted by lightning. The equally large building next door (different owners) have the exact same system and the exact same panels (same manufacturer and model), but it does not have the same lightning problem. Both buildings have the lightning spikes on the roof. Last storm that blew through knocked out not only our stuff, but phone and a lot of electrical too. Next door still had no problems. I'm no engineer, but I'm thinking the first building may not have a good ground system?
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Water pipes are not "ground". There are too many opportunities for a piece of plastic there. You should be going back to the ground electrode for the building. Even if you drove your own rod you would still be required to bond it to the ground electrode system.
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First you need to locate the complete circuit - the electrical path - that enters and leaves the alarm panel. Without that information, then you would only be guessing what might solve the problem.
Cold water pipes are not acceptable as earth grounds. The panel must be earthed to the same ground that all incoming utilities use. Furthermore, a most common path through alarm panel is AC electric. If AC electric does not have a 'whole house' protector connected withing signle digit feet of that earth ground, then you have a 'usual' suspect.
This was discussed in alt.security.alrams on 9 Feb 2001 in "Surge Protection" . Discussion reviewed at http://tinyurl.com/2gfsw and http://tinyurl.com/3dqc7
Aegis wrote:

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Thank you... EXTREMELY informative.

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| This is for you electrical engineers:
FYI: IANaEE
| I live in San Antonio and install alarm systems. We used to drive ground | rounds, but not anymore. We are now told to go to the nearest cold water | (copper) pipe for our ground. Problem is sometimes our panels still show | ground faults. Many times, while on the phone with tech support, we are told | to cut the ground wire and it will also, sometimes, actually fix the fault. | I was told by two manufacturers that no ground is better than a 'bad' | ground.
As others mention, you cannot depend on a water pipe for ground, even if it is copper or other metal all the way (which is not longer trustable).
Consider the following hazardous, but possibly undetected, scenario:
A few houses are grouped together on a single utility transformer that supplies common 240/120 center tapped single phase power. They are all grounded through the metal water pipe that is all metal all the way. One of the houses ends up, for whatever reason, with a broken neutral wire. Neutral current resulting from one or the other of the two hot wires at 120 volts having more load than the other cannot flow back to the transformer secondary through the neutral. If this broken neutral is between the ground bonding point and the service drop, then that neutral current will go out through the ground, to the water pipe, and distribute itself to the water pipes coming in through the neighbors, and cross through their bonding to their neutral and back to the power transformer.
If that doesn't worry you, I can give you another one that would be rare but also more hazardous.
You should ground to the ground wire (not the neutral wire) of the building at one point. If you get AC power, that ground wire is your path. If there is a ground fault problem, it needs to be corrected where it is caused, not covered up by cutting the wire. Cutting the wire only prevents detection of a hazardous condition; it does not solve anything.
If the building has no ground wire, there is no ideal solution, and what is the best depends on how it is wired.
I plan to have plastic, not metal, for all water and gas runs to my new house. It will also have an overrated grounding system suitable for both electrical and (ham) radio purposes.
| Also, have one large building always getting pelted by lightning. The | equally large building next door (different owners) have the exact same | system and the exact same panels (same manufacturer and model), but it does | not have the same lightning problem. Both buildings have the lightning | spikes on the roof. Last storm that blew through knocked out not only our | stuff, but phone and a lot of electrical too. Next door still had no | problems. I'm no engineer, but I'm thinking the first building may not have | a good ground system?
Bad ground is generally the cause. But this can also be influenced by variations in soil conditions, and other invisible conditions. This can exist even if the grounding systems are identical in both buildings (but one is still not as good as the other due to the other variations).
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