The **GMA-6-R** is a specific model of a fast-acting glass tube fuse, widely used in electronic equipment to protect circuits from overcurrent conditions. Below is a detailed technical breakdown of its parts and specifications. --- ### 1. General Specifications The part number follows a standardized naming convention in the electronics industry (commonly associated with brands like Eaton/Bussmann or Bel Fuse). | Feature | Specification | | :--- | :--- | | **Type** | Glass Tube Fuse | | **Current Rating** | 6 Amperes (6A) | | **Voltage Rating** | 125V AC / 250V AC | | **Speed/Characteristic** | Fast-Acting (F) | | **Dimensions** | 5mm x 20mm | | **RoHS Compliant** | Yes (indicated by the "-R" suffix) | --- ### 2. Physical Components The GMA-6-R consists of four primary physical parts: 1. **Glass Tube (Body):** The transparent cylindrical housing allows for easy visual inspection. If the fuse has blown due to a short circuit, you can often see a dark burn mark or a broken wire inside. 2. **Element (Wire):** A thin metallic wire calibrated to melt at exactly 6 Amps. Because it is "Fast-Acting," this wire is designed to snap almost instantly when the threshold is exceeded, protecting sensitive semiconductors. 3. **End Caps:** Made of nickel-plated brass, these caps provide the electrical contact points. They are crimped and often soldered to the internal element. 4. **Filler (Optional):** While some fuses use sand to quench arcs, the GMA series is typically "clear," meaning it is air-filled to allow for visibility. --- ### 3. Electrical Characteristics Understanding how this part behaves in a circuit is crucial for repair or design: * **Interrupting Rating:** This is the maximum current the fuse can safely stop without physically exploding. For the GMA-6-R, it is typically **200A at 125V AC** or **100A at 250V AC**. * **Voltage Drop:** There is a small resistance in the wire; at 100% load, you may see a drop of approximately 0.11 to 0.15 volts. * **Fast-Acting vs. Time-Delay:** Unlike "Slow-Blow" (MDL or GDC series) fuses, the GMA-6-R does not tolerate temporary "in-rush" currents. If a motor or large capacitor pulls 7A for even a fraction of a second, this fuse will blow. --- ### 4. Typical Applications The 5x20mm 6A fuse is common in: * Power supplies for desktop computers. * Consumer electronics (TVs, Audio Amplifiers). * Control panels for industrial machinery. * Laboratory equipment. --- ### 5. Part Number Breakdown | Segment | Meaning | | :--- | :--- | | **GMA** | Series name (5x20mm Fast-Acting Glass) | | **6** | Amperage rating (6 Amps) | | **-R** | RoHS compliant (Lead-free) |