The **3SBP4-R** is a specific type of electronic fuse manufactured by **Bel Fuse Inc.** It belongs to the 3SBP series, which is characterized by its miniature size and time-delay (slow-blow) performance characteristics. ### Technical Specifications Below are the primary technical parameters for the 3SBP4-R: | Parameter | Specification | |:---|:---| | **Fuse Type** | Glass Tube Miniature Fuse | | **Current Rating** | 4 Amperes (4A) | | **Voltage Rating (AC)** | 250V AC | | **Response Time** | Slow Blow / Time Delay (T) | | **Size / Dimension** | 6.3mm x 32mm (1/4" x 1-1/4") | | **Termination Style** | Axial Leaded (Pigtail) | | **RoHS Status** | Compliant (indicated by the "-R" suffix) | --- ### Key Features and Construction 1. **Axial Leads (Pigtails):** Unlike standard cartridge fuses that snap into clips, the "P" in the part number indicates axial leads. These are soldered directly onto a Printed Circuit Board (PCB), making them ideal for permanent installations where space is limited. 2. **Slow-Blow (Time-Delay) Characteristic:** This fuse is designed to withstand temporary "inrush" currents (spikes) that occur when a device is first turned on. It will only blow if the overcurrent persists, preventing "nuisance blowing." 3. **Glass Body:** The transparent glass body allows for easy visual inspection to determine if the internal filament has melted. 4. **RoHS Compliant:** The "-R" suffix confirms that the component is lead-free and meets environmental safety standards. ### Common Applications The 3SBP4-R is typically found in power supply circuits and industrial electronics where inductive loads (like motors or large capacitors) are present: * **Power Supplies:** Protecting the primary side of AC/DC converters. * **Consumer Electronics:** High-end audio equipment or appliances with small motors. * **Industrial Controls:** Used on control boards to protect sensitive components from short circuits while allowing for startup surges. ### Breaking Capacity It is important to note the **Interrupting Rating**. For the 3SBP series at 250V AC, the breaking capacity is typically: * 200 Amperes at 250V AC. * 10,000 Amperes at 125V AC. ---