GGT500 Ground Grid Tester

Ground Grid Tester GGT500 is a test set specially designed for inspection of substation ground grid. During a measurement the instrument generates 300 A during a time period of 60 s or longer. During the test current and voltage drop are measured and displayed simultaneously.
The test is performed with single set of current cables. One cable is connected to the referent grounding point in substation, and the second cable is connected to the testing ground point in the substation. With additional current clamps, current flow through the grounding is being inspected. Based on the current values measured with current clamps the state of the ground grid under the substation can be determined.
GGT500 can also be used as a standard micro ohmmeter for resistance measurement. As a micro ohmmeter to test low resistance values it can produce high test currents of up to 500 A.
GGT500 generates true DC ripple-free current with automatically regulated test ramps. During a test, the GGT500 ramps with increasing current before measuring and decreasing current after the measurement. This significantly eliminates magnetic transients.
The GGT500 instrument can store internally up to 500 measurements. All measurements are time- and date-stamped. Using the DV-Win software a test can be initiated and controlled from a PC and the results can be stored and displayed on it.
Communication between the GGT500 and PC is through an USB (as standard) or RS232 cable (as an option). DV-Win enables arranging the results as an Excel spread-sheet which can be later shown as a diagram and printed for a report.
The GGT500 instrument supports five separate test modes:

• Ground Grid mode
• SINGLE mode
• CONTIN mode
• BSG mode (Both Sides Grounded)
• DTR test mode (Dead Tank Resistance)