Looking for Circuit Diagram for Earth Ground Continuity Monitor (240V 50 Hz)

I bought one at a home improvement store or maybe Radio Shack. You might try the electrical/electronic section of a home improvement store and buy one off the shelf. It tells you with 3 LEDs the status of your wall socket wiring.

Thank for your advice.

I have tried it using a neon lamp with a series resistor connected between LIVE wire and EARTH wire.

But the socket tester could not monitor a true earth ground with an acceptable resistance value. Moreover, a socket tester is not designed to connect continuously on a supply of 240V AC 50 Hz.

I need an equipment which is sensible to the earth ground resistance.

Regards,

Water pipes are no longer acceptable earth ground points under the current edition of BS7671, as much of the distribution system these days is made of plastic pipe. Further, electrocution of a plumber because of an electrical fault will not make one popular with one's indemnity insurers.

Installing a separate local earth rod may be contrary to the local earthing arrangements required by the local utility, particularly if the distribution arrangements are other than TT, which is usually the earthing arrangment for rural areas fed from overhead cables.

All that can be done by the local user is the checking out the continuity of the house wiring between the earth pin of the plug and the earth terminal of the home distribution board. A simple multimeter from, oh, say Screwfix or RS (usual disclaimer) for about £10GBP and a long piece of wire to coomplete the loop so that the multimeter can be connected across the earth pin of the plug and the earth terminal of the dis board will suffice for this test.

If there is a residual doubt about the integrity of the upstream supply earthing arrangements following this test then a qualified electrician needs to be consulted to carry out an earth loop impedance test using specialised equipment. The electrician will issue a certificate of test for the installation. Expect to pay about £135GBP for this service. Suitably-qualified operations may be found using the Yellow Pages directory, which is supplied to every home that has a British Telecom land-line telephone service in use.

Hi joomunm,

Try this search site.

http://www.google.co.uk/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&hs=2EG&q=Circuit+Diagram+for+Earth+Ground+Continuity+Monitor&btnG=Search&meta=

Take care.

You state that you want to: "detect a hard connection between the ground wire of the AC plug ... and a true earth ground..."

I assume that to mean that you want to be able to VERIFY that your receptacles are, in fact, adequately grounded...(???)

This is not so cut-and-dried an issue as all-too-many people believe it to be.

Different soils exhibit different values of resistivity (essentially "resistance through a given cross-sectional area of soil") , and , that resistivity is known to change in some areas based on changes in the water table.

It might only be hundreds of Ω-cm in bayou or swamp-lands, and tens of thousands of Ω-cm in desert/arid areas (or dry rocky mountain area).

Assuming that you know where your local/residential "Ground rod/Earthing point" is located, your best bet *might* be (others will surely offer other solutions, no doubt) to use a special "Low-ohm-meter" to measure any resistance directly between each receptacle of concern and that ground reference point.

Can you explain just what EXACTLY is the specific nature of your concern or need of this test-measurement?

I need a device for continuous monitoring of the Earth Ground resistance.

Greetings ~

I must agree ('admit') that your responses here appear to be a bit ambiguous.

[info:] Many thousands of miles of pipelines criss-cross the United States like a giant spider's web. Those carrying gas, oil, and other hazardous liquids are protected against corrosion using cathodic protection (CP).

CP (in this case) involves anode beds buried alongside the pipeline right-of-way... a rectifier is involved, with the positive terminal going to the anodes, and the negative terminal attached to the pipeline.

NACE teaches corrosion engineers (and others in this field) how to determine the cathodic current demand load and how to provide said protection on such projects, and (among other things), this involves knowing the resistivity of the soil between the anodes and the pipeline.

There are a few ways to determine this, but probably the most popular is using a 4-pin test setup such as THIS , and knowing the formulas (and iterations of same) to reach the various depths of concern.

[end-info:]

Now ... I know that ELECTRIC_UTILITIES look at "grounding" somewhat differently , and the subject within *that* particular arena has always befuddled me.

This is due (in part) to the different requirements, with respect to Code compliance, in different states and even between adjacent counties [i.e., one county permitting more than a single ground rod on a given single-residence property, with the adjacent county NOT permitting multiple ground rods on the same class of real estate]. {Note; this may have changed in the last 15 years, having been removed from work in that environment}

Nonetheless ... YOUR POST / REQUEST is for "a device for continuous monitoring of the Earth Ground resistance".

Yet , you have not clarified for exactly what purpose you need this information, and thus (the way that *I* see it) nobody can answer EXACTLY and specifically to your requirements, unless they have a crystal ball...

In the hope of clarifying myself ; Post #7 suggested a rudimentary method for a simple "go/no-go" sort of a test (a crude measurement) ... which seems (by your initial post) to be "close" to what you are asking for. One cannot do much better , unless you specify the "significant digits" needed in the precision of your measurements.

There have been other CR4 threads about the subject of 'electrical-ground': e.g., here, here, here, here, (earth-loop impedance here), here, here ...

Take a moment to CLARIFY just EXACTly what you wish/want/need to monitor, and fill in the blanks here...

Wishing you the best ~

Thank for the positive response.

I have finally found the right stuff I am looking for under the commercial trade name of "HomeShield" http://www.homeguardsurge.com/?page=products. I have contacted them for a quotation a couple of days ago and no one has yet replied. I think it is an expensive apparatus and many people of my country will not be able to buy one.

I do not know if its specifications will suit the TT-Earthing system of my country.

Investigate and let me know.

Regards,

Hello Joomunm, To check the effectivness of grounds or newly imstalled rods, I use a trouble light with the end cut off. One lead goes to line (120v 60hz, line 1 of a residential panel) and the other to the ground rod itself or the ground wiring. I place a 100w bulb in thw trouble light then check bulb brightness first. Poor grounds will light dim. Then check cicuit amps and compare to connected load. I use a clamp on amp meter. load shouldread .83amps. This is not a permanent monitor but for my purposes it's enough to prove that it works once. Someone else may hve a way to make this permanent. Possibly with a large load resistor and a panel mount ammeter.