Ohm reading

[dwellselectric]

Question what device would you use if you wanted to get an ohm reading from a ground rod? Would it be a megger? And what is the reading supposed to be? Or should I say what reading should it be closest too? Thanks for your help

 

[stickboy1375]

Question what device would you use if you wanted to get an ohm reading from a ground rod? And what is the reading supposed to be? Or should I say what reading should it be closest too? Thanks for your help

What would you like the ohms to be?

 

[dwellselectric]

Thank you for the pic its very nice lol but what type of meter is it?

 

[augie47]

this will work

this will work

http://www.groundtesterstore.com/p2161/amprobe_gp-2_datalogging_ground_resistance_and_resistivity_tester.php

Amprobe GP-2 Datalogging Ground Resistance & Resistivity Tester


Amprobe GP-2 Datalogging Ground Resistance & Resistivity Tester. Measures Earth ground resistance - 3 point (fall of potential) or 2 point tests. Download test results to your PC using the RS-232 cable and software. Kit includes test leads, auxiliary electrodes and software.

$1,495.00
Save $161.00

$1,334.00

 

[stickboy1375]

Thank you for the pic its very nice lol but what type of meter is it?

Its a ground resistance meter http://www.idealindustries.com/prodDetail.do?prodId=61-920

 

[dwellselectric]

Gosh only about $1,500 thats cheap:roll:

 

[stickboy1375]

Gosh only about $1,500 thats cheap:roll:

especially since a 2nd ground rod is VERY cheap...

 

[dwellselectric]

I agee haha

 

[augie47]

but you sure can show that pesky inspector a thing or two :grin:

 

[dwellselectric]

Haha the inspector is a nice guy :roll:

 

[iwire]

That is one way, the standard way is a three point fall of potential test.

These are not cheap either.

 

[zog]

Clamp on ground resistance meters can only be used in limited appliactions and when are used are misused 90% of the time. The accuarcy of this method is very questionable.

A true fall of potential test is more accurate becuase when done properly is a proven value by the nature of the procedure.

A fall of potential test combined with a clamp on test input (Attached Rod Technuique) is the best test today, accuracy of a fall of potential test without the need for disconnecting the rod from the system.

 

[brian john]

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Clamp on ground resistance meters can only be used in limited applications and when are used are misused 90% of the time.

In my opinion you are being very kind with this low a level, based on reports I have reviewed.

Earth ground resistance tester, 3-point test, FOP (Fall of Potential) ground test.

And about the same percentages of these are not performed properly in my expierence.

 

[Lxnxjxhx]

Ohm reading

From page 10 of this manual

http://www.idealindustries.com/media/pdfs/products/instructions/61-920_instructions_v2.pdf

it looks like you could inject a few volts into the ground rods with a step-down transformer and measure the current with a conventional current probe, for way less than $1500. If you want freqs other than 60 Hz it gets a little more complicated.

 

[brian john]

I think you will find as Zog pointed out, that while this meter does have it uses, MOST test performed with this meter are not completed properly. Due to a variety of factors, first and foremost a lack of understanding the proper use of the meter. The primary reason this meter is used is trying to do it on the cheap (labor wise) and folks think it is EASY to use. If you are going to perform any electrical testing the first thing you learn is IGNORE the price. Because all test equipment is expensive. Meggers alone I probably have over 30,000.00 dollars tied up and that is the most basic of testers besides the multimeters and amp clamps.