The **MDL-2-1/4-R** is a specific model of electronic fuse manufactured by Eaton (Bussmann Series). It is a time-delay (slow-blow) glass tube fuse widely used in power supplies and industrial equipment. ### 1. Technical Specifications Below are the primary electrical and physical characteristics of this component: | Feature | Specification | | :--- | :--- | | **Current Rating** | 2.25 Amps (2-1/4 A) | | **Voltage Rating (AC)** | 250 VAC | | **Fuse Type** | Time-Delay / Slow-Blow | | **Material** | Glass Tube with Nickel-plated brass endcaps | | **Physical Size** | 1/4" x 1-1/4" (6.3mm x 32mm) | | **Interrupt Rating** | 100A at 250VAC / 10,000A at 125VAC | | **RoHS Compliant** | Yes (Indicated by the "-R" suffix) | --- ### 2. Breakdown of the Part Number Understanding the nomenclature helps in identifying equivalent parts or replacements: * **MDL**: The series name, signifying a time-delay glass tube fuse (standard 1/4" x 1-1/4"). * **2-1/4**: The amperage rating. In decimal form, this is **2.25 Amps**. * **-R**: Indicates the part is **RoHS compliant** (lead-free). --- ### 3. Key Electronic Characteristics #### A. Time-Delay (Slow-Blow) Mechanism Unlike "Fast-Acting" fuses, the MDL series is designed to withstand temporary surges in current. This is crucial for inductive loads like **motors or transformers** that experience a high "inrush current" when first powered on. The fuse will not blow immediately if the current slightly exceeds 2.25A for a fraction of a second, but it will blow if a sustained overload or short circuit occurs. #### B. Interrupting Rating This defines the maximum fault current the fuse can safely stop without physically exploding or arcing. The MDL-2-1/4-R is rated to handle up to **10,000 Amps** at a lower voltage (125V), making it very safe for standard household and light industrial circuits. #### C. Typical Applications * **Power Supplies:** Protecting the primary side of transformers. * **Consumer Electronics:** Used in older audio amplifiers and appliances. * **Industrial Control:** Protecting solenoid valves or small motors. --- ### 4. Safety and Replacement Note When replacing this part, ensure the replacement is also a **Time-Delay** fuse. Replacing a slow-blow MDL fuse with a fast-acting fuse (like the AGC series) will likely result in the fuse blowing immediately upon startup, even if the device is functioning correctly.