The **MDA-1-1/2-R** is a high-performance ceramic tube fuse manufactured by Eaton (formerly Bussmann). It is designed for applications that require a "Time-Delay" (slow-blow) characteristic and a high breaking capacity. --- ### Technical Specifications | Parameter | Specification | | :--- | :--- | | **Current Rating** | 1.5 Amperes (1-1/2 A) | | **Voltage Rating (AC)** | 250 VAC | | **Voltage Rating (DC)** | 125 VDC (commonly rated, check specific datasheet) | | **Fuse Body Material** | Ceramic Tube | | **Response Time** | Time-Delay (Slow-Blow) | | **Interrupting Rating** | 100A at 250VAC / 10,000A at 125VAC | | **Dimensions** | 1/4" x 1-1/4" (6.35mm x 31.75mm) | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### Key Features and Construction #### 1. Ceramic Body Unlike glass fuses, the ceramic body of the MDA series allows for a higher **Interrupting Rating** (Breaking Capacity). Ceramic can withstand higher internal pressures and temperatures during a short-circuit event without shattering. #### 2. Time-Delay (Slow-Blow) This fuse is engineered to ignore temporary current surges, such as the "inrush current" seen when a motor starts or a large transformer is energized. It will only blow if the overcurrent persists for a specific duration. #### 3. The "-R" Suffix The "R" in the part number signifies that the component is **RoHS compliant**, meaning it is manufactured without the use of lead or other hazardous substances restricted by European environmental standards. --- ### Common Applications Due to its robust construction and slow-blow nature, the MDA-1-1/2-R is typically found in: * **Industrial Control Panels:** Protecting small motors or solenoids. * **Power Supplies:** Filtering input stages where capacitors cause initial surges. * **Consumer Electronics:** Used in high-end audio equipment or appliances with inductive loads. ### Typical Trip Times | Percentage of Rated Current | Trip Time (approximate) | | :--- | :--- | | 110% | 4 Hours Minimum | | 135% | 60 Minutes Maximum | | 200% | 5 Seconds Minimum / 120 Seconds Maximum | ---