The Multi‑Amp ERT‑ACT5 ERT‑ACTS Trip Circuit Tester is a high‑current test set used to verify the short‑time, long‑time and instantaneous trip characteristics of industrial protection devices such as breakers and relays. Common failure modes for this class of equipment include damaged or corroded contactors, burnt relay coils, degraded insulation on power leads, and faulty internal fuses or diodes that prevent proper current injection. First‑check diagnostics should begin with a visual inspection of the test set’s power cables and connectors for signs of wear or damage; verify that the unit is receiving correct supply voltage (120 V/60 Hz) and that all internal fuse ratings match specifications. Next, confirm that the relay coils are energizing by measuring coil resistance and checking for continuity on the output contacts. Finally, review any error codes displayed on the tester’s panel or printed on its manual to identify specific component failures before proceeding with deeper circuit analysis.[oss-gpt-20b]