Do you know how to measure the earth resistance? if so
explain it

Answer Posted / nurul islam mallick

The Fluke 1625 earth ground tester is able to measure earth ground loop resistances for multi grounded systems using only current clamps. With this test method, two clamps are placed around the earth ground rod or the connecting cable and each are connected to the tester. A known voltage is induced by one clamp, and the current is measured using the second clamp. The tester automatically determines the ground loop resistance at this ground rod.



Ideally a ground should be of zero ohms resistance.
There is not one standard ground resistance threshold that is recognized by all agencies.

However, the NFPA and IEEE have recommended a ground resistance value of 5.0 ohms or less.

The NEC has stated to “Make sure that system impedance to ground is less than 25 ohms specified in NEC 250.56. In facilities with sensitive equipment it should be 5.0 ohms or less.”

The Telecommunications industry has often used 5.0 ohms or less as their value for grounding and bonding.

The goal in ground resistance is to achieve the lowest ground resistance value possible that makes sense economically and physically.

Is This Answer Correct ?    2 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is the formula for hv test for cable and circuit breaker..????

1554


Why is it prefer to initiate circuit breaker failure by "86" lockout relay not by "94" tripping relay ?!

1318


How many kw will suply from one db

1081


33kv Rated output avilable in market (any where in india)

1639


I have c license but I don't know eligibility of Max Kilo Volts under the electrical licensing board.

1229






Generation of voltage for each phase are same of a turbogenerator.Although the short circuit current flow when two phase of turbogenerator are shorted(where current can't flow without potential difference),why?

1656


what parameters are should nessary for control technic dc drive(in rolling mills)?

1522


List the time domain specifications.

648


The sodium vapor lamp is not glows when it is connected a distance of 5 meters above from gearbox, why ?

3213


If VFD is On but no starting commond on it. so how many outpout voltages of VFD

699


Connection diagram for KW meter and  Kva meter

1797


lenz law application and define

2234


in Contactor opearation Why there is a difference in the values of the operate and release voltage in case AC supply

1581


how we can set the IDMT relay.

1681


How to decide cable tray size?

729