How to build an Earth (Ground) Resistance Continuous Monitoring Device?

What is your application?

Cabe

Hi,

I am looking for an Earth Resistance Continuous Monitor Device operating on 230VAC 50HZ to verity the Earth/Ground (TT system) every second. In case the resistance drops below the parameter (25~100 ohms), a visual (LED) is lighted plus an audible alarm is heard.

Refer to link below:

http://www.transorbelectrical.com/pq/technical/HomeShield.pdf

Hope this link will be self explanatory.

Thanks.

Regards,

Hi all,

In a place which has more than 200 earthing pits for power and lightning arrestor. Weekly checks are required to be done which is a herculean tasks moreso that manpower cannot be consistent and may also sham on doing the same. I am looking for a solution where in the system can be installed for automatic checking and monitoring so that the values can be read on a daily/ weekly basis with one monitor and print of the output can be put up for validation. Does anyone know of such a system and the firm/vendor which supplies and installs the same. Finance is not a constarint

Hi Mamade,

Can you confirm that you want to test the resistance between a piece of equipment and the Earth Ground. Your second post indicated that you wanted a visual and sound alert if the resistance to ground gets below 100 ohms. For clarification is the piece of equipment grounded or isolated from ground. Your specification for the alarm would indicate that you do not want there to be a ground circuit and want an alarm if there is a connection to Earth Ground.

John

Hi Mamade,

Can you confirm that you want to test the resistance between a piece of equipment and the Earth Ground. Your second post indicated that you wanted a visual and sound alert if the resistance to ground gets below 100 ohms. For clarification is the piece of equipment grounded or isolated from ground. Your specification for the alarm would indicate that you do not want there to be a ground circuit and want an alarm if there is a connection to Earth Ground.

John

Hi This is resistance between equipment and earth. Further audio and visual warning are desired if  reading of  resistance value goes above 08 ohm.

I think the problem is that they need to check the quality of the connection of an earth spike (for want of better description) to actual Earth.

It's not easy - in an installation with multiple earth spikes, like Ashish has, you could measure the resistance from one spike to all the other spikes but that is actually very difficult to do (since I assume that the installation must work without interruptions).

MK

Can you describe what the check is these people do.

In the earlier days we used to apply a heavy current to test that the resistance was low and more importantly that the earth lead could take the necessary current.

It has been raised that simply measuring the resistnace doesn't verify the connection will handle the required fault current.

You could apply a current and measure the voltage during the test.

Mark

Hi all,

I was discussing the problem with my colleagues and it emerged that the similar contraption has been used and installed in smart homes which has a large number of heavy load appliances. The same is monitored and displayed in case there is a break down in the earthing. However, in these homes the power supply earth maybe only one......My issue is a bit different that I have a number of earthing points and i need a system to measure values of the resistance easily without any human errors.

Another thought is that Installing a sensor/ transducer in the output /where we measure values and then bring them to one monitor could be a solution but the extent of wiring through out that land area is another matter of concern. 

Regards

The same is monitored and displayed in case there is a break down in the earthing.

You aren't confusing an Earth leakage Detector are you.?

These detect any in-balance in phase and neutral current and disconnect the power to that circuit.

As jw0752 has pointed out there are some other issues that could be introduced.

Are you able to do any form of schematic to show the connections, in some form of relative way to each other.

The reason is that unless you have your reference at the centre of the multiple earth rods, you may get an in-balance and current may actually flow up the earth rod, through the mains earth/neutral (in NZ/AUS the neutral and earth are the same potential).

This might still register within the acceptable reading.

I understand that testing is a pain, but there are good reasons why it's done.

You might be able to use a low voltage high current system which you connect to the earth and measure and record each time.

This will show any trend or sudden change.

Many of the commercial testers have the ability to record, which removes the operator from the equation.

Mark