### MDA-4-R Electronic Component Overview The **MDA-4-R** is a specific model of a time-delay (slow-blow) fuse, manufactured by **Eaton (formerly Bussmann)**. It is part of the MDA series, designed for high-current applications where temporary power surges occur. --- ### Technical Specifications The following table outlines the primary electrical and physical characteristics of the MDA-4-R: | Attribute | Specification | | :--- | :--- | | **Current Rating** | 4 Amperes | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Ceramic Tube, Time-Delay (Slow-Blow) | | **Interrupt Rating** | 200A at 250VAC / 10,000A at 125VAC | | **Dimensions** | 1/4" x 1-1/4" (6.3mm x 32mm) | | **Material** | Ceramic body, Nickel-plated brass endcaps | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### Key Features and Construction 1. **Time-Delay Functionality**: Unlike "Fast-Acting" fuses, the MDA-4-R is designed to withstand short-term inductive surges (like motor startups or transformer inrush currents) without blowing. It will only open the circuit if the overcurrent persists. 2. **Ceramic Body**: The use of a ceramic tube instead of glass allows for a higher **Interrupting Rating**. In the event of a severe short circuit, the ceramic housing can withstand higher internal pressures and temperatures without shattering. 3. **The "-R" Suffix**: In the Eaton/Bussmann naming convention, the **-R** indicates that the part is lead-free and complies with **RoHS (Restriction of Hazardous Substances)** directives. --- ### Applications The MDA-4-R is commonly found in the following electronic environments: * **Industrial Controls**: Protecting circuits with high inductive loads. * **Power Supplies**: Managing initial capacitor charging surges. * **Large Appliances**: Protecting motors that draw high current upon starting. * **Test Equipment**: Ensuring safety in high-voltage laboratory settings. --- ### Comparison: MDA vs. MDL Series | Feature | MDA Series (e.g., MDA-4-R) | MDL Series (e.g., MDL-4-R) | | :--- | :--- | :--- | | **Body Material** | Ceramic (Opaque) | Glass (Transparent) | | **Interrupt Capacity** | High | Low to Medium | | **Visibility** | Cannot see if blown | Internal filament visible |