Ground Bond Tester

A ground bond tester (also called an earth bond tester) checks that the protective earth path, from the earth pin of the mains plug to every accessible metal part, can carry a fault current. It passes a high current through that path and measures its resistance in milliohms. The high current is what shows up a loose screw, a weak crimp or a painted joint that a low-current continuity check could pass. Ground bond testing is called for by product safety standards including IEC 62368-1, IEC 60601-1, IEC 60335-1 and BS EN 60204-1. The standard sets the test current, which is often linked to the rating of the product's protective device. Our range includes the GW Instek GCT-9040 (3 to 40 A, four-terminal measurement), the SCI 260 Series (40 A on the Model 264, 60 A on the Model 266) and the Associated Research HYAMP Series (AC or DC to 40 A). Multi-function analysers such as the Associated Research OMNIA II and the SCI 440 Series add 40 A ground bond to hipot and insulation resistance. All are available to buy or rent.