The RCDT tests not only type A and type AC RCDs, but also the selective (time-delayed) variants of both types, performing 1⁄2I, 1I and 5I tests on RCDs rated at 30 mA, 100 mA, 300 mA and 500 mA tested at 0° or 180°. The RCDT320 offers additional tests for RCDs rated at 10 mA and 1000 mA.