### FRS-R-450 Fuse Specifications and Overview The **FRS-R-450** is a high-capacity industrial fuse belonging to the Fusetron™ family, manufactured by Eaton (Bussmann Series). It is a dual-element, time-delay fuse designed for heavy-duty electrical protection. --- ### Technical Specifications | Parameter | Specification | |:---|:---| | **Part Number** | FRS-R-450 | | **Amperage Rating** | 450 Amps | | **Voltage Rating (AC)** | 600 Vac | | **Voltage Rating (DC)** | 300 Vdc | | **Interrupting Rating (AC)** | 200,000 Amps RMS Symmetrical | | **Interrupting Rating (DC)** | 20,000 Amps | | **Class** | RK5 | | **Fuse Body Material** | Fiberglass Tube | | **Termination Style** | Blade (Knife Blade) | --- ### Key Features and Electronic Design #### 1. Dual-Element Construction Unlike standard fast-acting fuses, the FRS-R-450 contains two distinct elements: * **Thermal Element:** Handles long-term overloads. It allows temporary surges (like motor startups) without blowing. * **Instantaneous Magnetic Element:** Responds immediately to high-level short circuits to prevent catastrophic equipment failure. #### 2. Time-Delay Functionality This fuse is engineered to provide a minimum 10-second delay at 500% of the rated current. This is critical for industrial applications where inductive loads (motors, transformers) draw high "inrush" currents that would trigger a standard fuse. #### 3. Current Limitation As a Class RK5 fuse, it provides significant current limitation. In the event of a short circuit, the fuse reacts so quickly that it prevents the fault current from reaching its full potential magnitude, protecting downstream components from thermal and mechanical stress. --- ### Common Applications * **Large Motor Branches:** Provides superior protection for large industrial motors. * **Main Feeders:** Used in service entrance equipment. * **Branch Circuit Protection:** Protects lighting and heating circuits. * **Inductive Loads:** Ideal for transformers and solenoids where high inrush is expected. --- ### Cross-Reference and Equivalents If the Bussmann FRS-R-450 is unavailable, the following are industry equivalents: * **Littelfuse:** FLSR450 / FLSR450ID * **Mersen (Ferraz Shawmut):** TRS450R