The **FRS-R-1-1/2** is a specialized industrial electrical component, specifically a dual-element, time-delay fuse from the **Fusetron™** series manufactured by Eaton's Bussmann Division. --- ### 1. Technical Specifications The part number follows a specific nomenclature that defines its electronic characteristics: | Parameter | Specification | |:---|:---| | **Series** | FRS-R (Fusetron™ dual-element, time-delay) | | **Current Rating** | 1.5 Amps (1-1/2 A) | | **Voltage Rating (AC)** | 600 Vac | | **Voltage Rating (DC)** | 300 Vdc | | **Interrupting Rating (IR)** | 200,000A RMS Symmetrical (at 600Vac) | | **Class** | Class RK5 | | **Dimensions** | 5.0" Length x 0.81" Diameter | --- ### 2. Key Electronic Features #### Dual-Element Design Unlike a standard fast-acting fuse, the FRS-R-1-1/2 contains two distinct elements: 1. **Thermal Element:** Handles low-level overloads. It allows momentary surges (like motor startups) to pass without blowing the fuse. 2. **Instantaneous Element:** Acts as a short-circuit protector. If a massive fault occurs, it clears the circuit in microseconds to protect equipment. #### Time-Delay Characteristics This fuse provides a minimum of **10 seconds** of delay at 500% of the rated current (7.5A). This is critical for inductive loads where "inrush current" would otherwise cause nuisance tripping of standard fuses. #### Rejection Feature (RK5) The "R" in FRS-R indicates a "Rejection" tip. This physical design prevents the installation of lower-rated fuses (like Class H) into a Class R fuse block, ensuring that the safety integrity of the system is maintained. --- ### 3. Common Applications Due to its low amperage but high voltage rating, the 1.5A version is typically used for: * **Small Motor Protection:** Protecting fractional horsepower motors. * **Control Transformers:** Safeguarding the primary or secondary side of control circuits. * **Solenoids:** Providing overcurrent protection for inductive coils. * **Branch Circuit Protection:** General-purpose protection in industrial panels where 600V capacity is required. --- ### 4. Comparison with Similar Models | Model | Voltage | Delay Type | Main Use Case | |:---|:---|:---|:---| | **FRS-R-1-1/2** | 600V | Time-Delay | Motor/Transformer circuits | | **FRN-R-1-1/2** | 250V | Time-Delay | Same application, lower voltage | | **KTS-R-1-1/2** | 600V | Fast-Acting | Sensitive electronics (no inrush) |