Electrical Ground Testing Procedure

Department of agriculture usda rea bulletin 1751f 802.

Electrical ground testing procedure.

The first is the 3 point or fall of potential method and the second is the induced frequency test or clamp on method. Ground testing is used to measure the performance of this circuit and check if it meets requirements. Neta world techtips ground testing in difficult installations by jeffrey r. However there are key differences between these two tests.

Standards procedures for testing the electrical ground system. Electrical circuits have a separate ground or earth circuit that provides an alternate low impedance path for electricity to safely reach the ground in case of accidental physical contact. Prior to about 15 years ago the basic methodology for ground testing remained fundamentally unchanged since it was originally devised in the early 20th century. You re simply checking for a continuous path on a ground circuit.

In areas where driving ground rods may be impractical the two point method can be used. Download paper c the four potential method wenner method this technique helps overcome some of the problems associated with the requirement for knowing the electrical centre of the earthing systems being tested. Four of the most common methods of ground resistance testing used by test technicians are discussed below. Purpose method a dc low current test to check circuit resistance.

Inadequate electrical grounding or wiring on the customer s premises or. Not just power isolation but also removal of any neutral or other such ground. There are two 2 methods for testing an electrical grounding system. On modern electrical systems rcd s and rcbo s are regularly fitted these devices react to electricity missing from the circuit or installation such as when a person is receiving an electric shock as the electricity passes through his body to the ground earth.

Insert 2 ground probes into the ground. Ansi ieee std 81 1983 ieee guide for measuring earth resistivity ground impedance and earth surface potentials of a ground system. The procedures for earth resistance testing are referenced in ieee standard no. The furthest ground probe needs to be at a distance that is 10 times the length of the ground rod.

2 point dead earth method. An illustration from the us nbs 1918 procedure for electrical ground testing. Ground continuity testing ground continuity testing is the same concept as ground bond testing. The ground probes need to be inserted into the ground at specific distances away from the ground rod.

Similar concept to the ground bond testing. Testing procedures have been also developed. Beyer wally electrical protetion grounding fundamentals pdf 1994 u s.