## FRS-R-210 Fusetron™ Class RK5 Fuse The **FRS-R-210** is a heavy-duty, dual-element, time-delay fuse manufactured by Eaton (Bussmann Series). It is designed to provide high-level protection for industrial electrical circuits, particularly those involving high motor loads. ### 1. Technical Specifications The following table outlines the core electrical characteristics of the FRS-R-210: | Feature | Specification | | :--- | :--- | | **Manufacturer** | Eaton (Bussmann Series) | | **Amperage Rating** | 210 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 | | **Design Type** | Dual-element, Time-delay | --- ### 2. Key Features and Functions * **Dual-Element Design:** Unlike standard fuses, this part contains two separate components. One handles short-circuit protection (instantaneous), while the other manages thermal overloads (time-delayed). * **Time-Delay (Slow-Blow):** It is engineered to ignore temporary current surges, such as when a large industrial motor starts up. This prevents "nuisance tripping" while still protecting the circuit from sustained overloads. * **Current Limiting:** The RK5 classification means it is highly effective at limiting the let-through energy during a short-circuit event, protecting downstream components from physical damage. * **Rejection Feature:** The "R" in FRS-R signifies a rejection feature. This prevents a lower-rated fuse (like a Class K) from being installed in a Class R fuse clip, ensuring the safety integrity of the system. --- ### 3. Common Applications The FRS-R-210 is typically found in industrial and commercial environments, specifically: 1. **Motor Branch Circuits:** Its time-delay property allows motors to draw high starting current without blowing the fuse. 2. **Transformer Protection:** It handles the initial "inrush" current of transformers. 3. **Main Feeders:** Used in large electrical panels to provide high-capacity overcurrent protection. 4. **Inductive Loads:** Any circuit with high inductance where current spikes are expected during switching. --- ### 4. Dimensional Data * **Diameter:** 2.36 inches (approx. 60mm) * **Length:** 11.63 inches (approx. 295mm) * **Mounting:** Blade-style terminals (Knife-blade) ---