The **GMD-2.5-R** is a specific type of electronic component, specifically a **Glass Tube Fuse** belonging to the GMD series manufactured by **Eaton (formerly Bussmann)**. It is designed for low-power applications requiring time-delay characteristics. --- ### 1. Technical Specifications The part number "GMD-2.5-R" can be broken down into its technical attributes: | Parameter | Specification | | :--- | :--- | | **Series** | GMD (5mm x 20mm format) | | **Current Rating** | 2.5 Amperes | | **Voltage Rating** | 250 VAC | | **Fuse Type** | Time-Delay (Slow-Blow) | | **Material** | Glass Tube with Nickel-plated Brass Endcaps | | **Interrupt Rating** | 100A at 250VAC | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Physical Characteristics * **Dimensions:** It follows the standard small-dimension format of **5mm (diameter) x 20mm (length)**. * **Mounting:** It is typically used in panel-mount fuse holders, PCB clips, or inline fuse holders. * **Visual Check:** Because it is a glass tube, the internal filament is visible. In a "slow-blow" fuse like this, the element often has a small coil or a tiny drop of solder (a "T-element") to provide the necessary thermal mass for time-delay. --- ### 3. Functional behavior: Time-Delay The "GMD" series is characterized as **Time-Delay**. Unlike "Fast-Acting" fuses that blow instantly upon hitting the current limit, the GMD-2.5-R is engineered to: 1. **Withstand Inrush Current:** It ignores temporary spikes (like when a motor or transformer starts up). 2. **Protect against Sustained Overload:** It will open the circuit if the 2.5A limit is exceeded for a prolonged period. --- ### 4. Applications This specific fuse is commonly found in: * **Consumer Electronics:** Power supplies for TVs and audio equipment. * **Industrial Equipment:** Small control circuits and PLCs. * **Chargers:** Laptop power adapters or battery charging stations. --- ### 5. Ordering and Replacements When replacing this part, ensure the following markers match: * **Voltage:** Can be 250V or higher (never lower than the circuit voltage). * **Amperage:** Must be exactly 2.5A. * **Speed:** Must be "T" (Time-delay/Slow-blow). Replacing this with a "Fast-acting" fuse will likely cause it to blow immediately upon device startup.