What type of test is used to ensure the functionality of ground fault circuit interrupters (GFCIs)?

A function test is specifically designed to verify the operational effectiveness of ground fault circuit interrupters (GFCIs). This test simulates a ground fault condition to ensure that the GFCI reacts appropriately by tripping and cutting off power. Performing a function test typically involves pressing the 'test' button on a GFCI device, which should cause it to trip, indicating that it can perform its intended protective function.

In contrast, other tests like continuity tests assess the ability of electrical connections to conduct current, insulation resistance tests measure the integrity of the insulation material used in electrical systems, and voltage drop tests evaluate the efficiency of a circuit in delivering voltage to devices. While these tests are essential in their own contexts, they do not specifically address a GFCI's critical function of detecting ground faults and ensuring safety against electrical shock.