The **FRN-R-75** is a high-performance industrial fuse commonly used in electrical and electronic systems for overcurrent protection. It is a member of the **Fusetron™** series manufactured by Eaton (Bussmann Division). --- ### ## Technical Specifications Below is a breakdown of the key technical parameters for the FRN-R-75: | Feature | Specification | | :--- | :--- | | **Amperage Rating** | 75 Amps | | **Voltage Rating (AC)** | 250 Volts | | **Voltage Rating (DC)** | 125 Volts | | **Interrupting Rating** | 200,000 Amps RMS Symmetrical (at 250V) | | **Fuse Class** | Class RK5 | | **Type** | Dual-Element, Time-Delay | | **Body Material** | Fiberglass or Melamine | --- ### ### Key Characteristics 1. **Dual-Element Design**: The fuse contains two separate components. One provides a **thermal cutout** for long-term overloads, and the other provides a **magnetic element** for high-level short-circuit protection. This allows the fuse to distinguish between temporary surges and dangerous faults. 2. **Time-Delay Functionality**: The "Time-Delay" feature is critical for circuits involving inductive loads (like motors). It allows for a momentary high current "inrush" during motor startup without blowing the fuse, while still protecting the circuit if the high current persists. 3. **Class RK5 Safety**: Class RK5 fuses are "Rejection" type fuses. They have a specific physical shape (usually a notch or a specific blade design) that prevents them from being replaced by a lower-rated fuse (like Class H), ensuring the safety of the electrical installation. --- ### ### Typical Applications The FRN-R-75 is primarily used in the following scenarios: * **Motor Branch Circuits**: Protecting individual motors from burnout while allowing for startup current. * **Transformer Protection**: Handling the primary and secondary protection of power transformers. * **General Feeder Circuits**: Serving as the main disconnect protection in industrial panels. * **HVAC Systems**: Protecting large air conditioning and heating units. --- ### ### Comparison with Similar Fuses | Part Number | Voltage | Speed | Use Case | | :--- | :--- | :--- | :--- | | **FRN-R-75** | 250V | Time-Delay | Standard industrial (Inductive loads) | | **FRS-R-75** | 600V | Time-Delay | High-voltage industrial applications | | **NON-75** | 250V | Fast-Acting | Resistive loads (No inrush current) |