Bussmann FNQ-R-4 Current Limiting Time Delay Fuse

The Bussmann FNQ‑R‑4 is an Eaton Bussmann Series Class CC Limitron current‑limiting time‑delay fuse rated at 4 A, designed to protect control circuits and small transformers in industrial equipment. This rejection‑style, dual‑element fuse tolerates brief inrush currents typical of control transformers while providing fast clearing during sustained faults, helping downstream devices survive transient overloads. It carries a 600 V AC rating and a 200 kA interrupting rating, making it suitable for low‑ to mid‑voltage circuits such as small control transformers, industrial control panels, and branch circuits with startup surges. The FNQ‑R‑4 uses ferrule‑end terminals on a cylindrical melamine body measuring about 13/32 in (0.406 in) in diameter and 1‑1/2 in long, and is offered in a non‑indicating form compatible with CC fuse holders. Applications include protection of small control transformers, line protection in industrial controls, and circuits where brief overcurrents occur during startup.