Re: belkin power conditioner for my Samsung LCD - is it worth it???

w_tom wrote:


We install earth ground for multiple reasons. Earthing is required
for human safety so that a fault will trip a circuit breaker.

Descriptions up to here are quite good. But earthing is not allowed to be used to trip a circuit breaker. The path to trip a circuit breaker must be metal. The path is building ‘ground’ wires to the electrical service panel, through a ‘ground’ to neutral bond connection, to the service neutral and back to the transformer. A breaker would trip if the building ‘ground’ was not connected to earth. Part of the problem talking about ‘grounding’ is that there are 2 functions - bonding to trip a circuit breaker, and connecting the ‘ground’ system to earth to limit the voltage from power wires to earth and provide a path to ‘sink’ surges and, for example, if a high voltage wire drops on the ‘low’ voltage wires to your house.



Not only are all those interconnected grounds different. For surge
protection, the building's earth ground must be a common ground to all
incoming utilities.

But common ground is not enough. The entry protectors for phone, cable, .... must connect with a *short* wire to the earthing wire at the power service. This is called a "single point ground". With a strong surge earth current the system ‘ground’ will always lift above ‘absolute’ ground. You want the ‘grounds’ for the power, phone, cable, ... to lift together. An example of not having a good single point ground is illustrated in the IEEE guide:
http://omegaps.com/Lightning%20Guide_FINALpublishedversion_May051.pdf
starting pdf page 40.

Francois Martzloff, 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."



Above discusses the why? Another post discusses the 'hows' of
earthing for surge protection in comp.sys.mac.comm on 4 Jul 2007
entitled "DSL speed" at
http://tinyurl.com/2gbgef

While you are at, read my responses.


Others have also discussed these concepts such as in
rec.radio.amateur.antenna on 1 Jan 2007 entitled "Acceptable
Lightning Ground?" at
http://tinyurl.com/y9bfuz or another at:
http://lightningsafety.com/nlsi_lhm/rtaf3.html or another at:
http://tinyurl.com/2aymw9
The ideal plan is a single point ground with no sneak paths. Sneak paths
are loops that allow lightning current to flow into the equipment room.

Bud will respond as he routinely does complaining that many of these
examples are about radio stations. He says you are not operating a
radio station - only to confuse. Every incoming wire to the building
is a radio antenna to that appliance.

w_ has a fetish for tower antennas. Most people do not expect their power wires to be hit by lightning near the house. If you have a tower antenna, you better expect the tower will be hit.

There are actually good sources of information on surge protection and earthing that do not center on tower antennas.



Exact same applies to surge protection. A protector simply makes a
connection to that earth ground. But earth ground - the quality of
and how that connection is made - determines 'system' effectiveness.
Yes - system. Surge protection is a 'system' where the only required
component is a single point earth ground.

Everyone is for earthing.
The IEEE guide, in the example starting pdf page 40, illustrates that plug-in suppressors work by clamping the voltage on all wires (signal and power) to the common ground at the suppressor. They do not work primarily by earthing. The guide explains that earthing occurs elsewhere in the system.

Surge protection built into equipment like TVs obviously does not have a short connection to earth either. Insurance information indicates equipment particularly vulnerable to surges has connections to both power and signal (phone, cable).

The IEEE guide in its section on examples says:
"The previous sections have shown, in general, how to protect electronic systems in houses:
1) Proper grounding and bonding, especially at the service entrance.
2) AC panel and primary signal surge protection at or near the service entrance.
3) Multi-port plug-in protectors near the equipment to be protected."


A
protector is only as effective as its earth ground.

And the required statement of religious belief in earthing.



Demonstrated is why every high reliable facility is fanatic about
its earth system. It must suffer hundreds of direct strikes and never
suffer damage. What determines no damage? How good is that earthing
and connections to earthing? No earth ground means no effective
protection.

The only way to protect a structure from direct strikes is to install a lightning rod system.



For reliable advice, read the IEEE and/or NIST guides.

--
bud--
.

Relevant Pages

  • Re: Daisy chining surge protectors
    ... First that discussion of earthing is long because the 'so simple thing' ... Standards for earthing - for home surge protection - do not exist. ... No earth ground means protection inside appliances can be overwhelmed. ...
    (rec.audio.pro)
  • Re: Ground Rod For House ?
    ... Provided was an example of wire impedance (it was not a ... earthing is good for human safety but essential to transistor ... Above is about earthing for the secondary protection ... Each layer of protection is defined by its single point earth ...
    (alt.home.repair)
  • Re: Power Conditioners Worth the Money?
    ... protect by shunting to earth because a necessary earthing wire does not ... device grounds the incoming signal connection point of the ... So what is required for protection? ... Co-located as in the short connection to earth. ...
    (alt.tv.tech.hdtv)
  • Re: PCs plugged into power strip into ungrounded GFCI?
    ... I thought that two pronged outlets were ungrounded. ... But you say that they might be grounded; either through an earth ground ... earth ground exists, then no effective protection. ... this same earthing electrode. ...
    (sci.electronics.basics)
  • Re: House Power Failures and Mac
    ... in front of each of my UPSes, precisely because the built-in surge protection ... If lightning will not blow through UPS's AC/DC converter, ... In earth ground. ...
    (comp.sys.mac.apps)
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