Siemens 48FM4R 4G 25 131 891 503 Current Limiting Fuse

Siemens 48FM4R-4G is a high‑voltage current‑limiting fuse from the FM family, designed to protect medium‑voltage motor starters and distribution circuits by interrupting fault currents while limiting let‑through energy. It is rated for 2400–4800 VAC (2.4–4.8 kV) and carries the 48FM4R‑4G designation, with the catalog number 25‑131‑891‑503. This model is used in Siemens/Allis Chalmers motor‑starter assemblies and other industrial control gear to safeguard feeders and downstream equipment from short circuits. The fuse shares compatibility with Siemens FM fuse holders, enabling straightforward replacement in high‑voltage protection applications. Published specifications list the unit at about 9.6 lb (4.4 kg), reflecting its robust construction for industrial environments. When sourcing, reference the 48FM4R‑4G code and the 25‑131‑891‑503 part number to ensure the correct Ferrule/FM current‑limiting fuse type is matched to your Siemens protection scheme and related equipment.