1. บทนำ
This manual provides essential information for the safe and effective use of the Littelfuse FLNR045 FUS 250V T/D Class RK5 45A fuse. Please read this manual thoroughly before installation or operation and retain it for future reference. This fuse is designed for use in panel accessories and electrical systems requiring reliable overcurrent protection.
2. ข้อมูลด้านความปลอดภัย
คำเตือน: Electrical shock hazard. Improper installation or use of this product can result in serious injury or death. Always follow local electrical codes and safety regulations.
- Ensure power is disconnected at the main circuit breaker or fuse panel before installing, inspecting, or replacing fuses.
- บุคลากรที่มีคุณสมบัติเหมาะสมเท่านั้นที่ควรทำงานเกี่ยวกับไฟฟ้า
- Use appropriate personal protective equipment (PPE), such as insulated gloves and eye protection.
- Verify the correct fuse rating (voltagอีและ amperage) for the circuit. Using an incorrect fuse can lead to equipment damage or fire.
- อย่าบายพาสหรือตamper with fuses.
3. คำอธิบายและคุณสมบัติของผลิตภัณฑ์
The Littelfuse FLNR045 is a 45 Amp, 250 Volt, Class RK5, dual-element, time-delay fuse. It is designed to provide superior protection for motors and other inductive loads against both overloads and short-circuits. Its time-delay characteristic allows for temporary inrush currents without nuisance opening, while still providing fast-acting protection under short-circuit conditions.

Figure 3.1: A Littelfuse FLNR045 Class RK5 time-delay fuse. This image shows the cylindrical body of the fuse with the Littelfuse brand and "CLASS RK5 Time Delay Dual Element" visible on its label.
คุณสมบัติหลัก:
- Dual-Element Construction: Provides both overload and short-circuit protection.
- Time-Delay Characteristic: Prevents nuisance blowing from temporary overcurrents, such as motor starting.
- Class RK5 Rating: Offers current-limiting capabilities, reducing damage to components during short-circuit events.
- UL จดทะเบียน: Meets safety standards for reliable performance.
4. การตั้งค่าและการติดตั้ง
Installation of the FLNR045 fuse should only be performed by a qualified electrician in accordance with all applicable national and local electrical codes.
- ตัดกระแสไฟออกจากวงจร: Before beginning any work, ensure that the circuit where the fuse is to be installed or replaced is completely de-energized. Verify with a voltagอีผู้ทดสอบ
- Identify Fuse Holder: Locate the appropriate fuse holder or disconnect switch for the circuit requiring protection.
- Insert Fuse: Carefully insert the FLNR045 fuse into the fuse clips or holder, ensuring a secure and proper connection. Do not force the fuse.
- ตรวจสอบการติดตั้ง: Double-check that the fuse is seated correctly and that all connections are tight.
- Re-energize Circuit: เมื่อการติดตั้งเสร็จสมบูรณ์และตรวจสอบแล้ว ให้จ่ายไฟให้กับวงจรอีกครั้ง
It is critical to match the fuse's voltagอีและ amperage ratings to the circuit's requirements. Using a fuse with an incorrect rating can lead to system failure or hazardous conditions.
5. หลักการทำงาน
The Littelfuse FLNR045 is a current-limiting, time-delay fuse. This means it is designed to:
- Protect against Overloads: The dual-element construction allows the fuse to withstand temporary overcurrents (e.g., motor starting surges) for a specified duration without opening. If an overload persists, the fuse element will melt and open the circuit.
- Protect against Short-Circuits: In the event of a severe short-circuit, the fuse acts very quickly to interrupt the fault current, limiting the peak current and energy let-through. This rapid response helps prevent damage to upstream and downstream components.
The time-delay feature is particularly beneficial in circuits with inductive loads that draw high inrush currents upon startup, preventing unnecessary fuse blows and ensuring continuous operation.
6. การบำรุงรักษา
Fuses are generally maintenance-free components. However, periodic inspection of the fuse and its holder is recommended as part of routine electrical system maintenance.
- การตรวจสอบภาพ: With power disconnected, visually inspect the fuse for any signs of damage, discoloration, or cracking.
- Holder Inspection: Check the fuse holder clips for corrosion, looseness, or signs of overheating. Ensure good contact with the fuse ends.
- การทดแทน: If a fuse has blown (indicated by an open circuit when tested with a multimeter, or visible damage), it must be replaced with an identical fuse (same brand, model, voltagอี และ amperage rating). Never replace a fuse with one of a higher rating.
7 การแก้ไขปัญหา
If a circuit protected by the FLNR045 fuse loses power, the fuse may have blown due to an overcurrent condition. Follow these steps:
- ตัดกระแสไฟออกจากวงจร: Immediately disconnect power to the affected circuit at the main panel.
- ระบุฟิวส์ขาด: Carefully remove the fuse (using appropriate tools if necessary) and test it with a multimeter for continuity. A blown fuse will show an open circuit (no continuity).
- Investigate Cause: Before replacing the fuse, identify and rectify the cause of the overcurrent. Common causes include:
- Short-circuit in wiring or equipment.
- Overloaded circuit (too many devices drawing power).
- Faulty appliance or motor.
- เปลี่ยนฟิวส์: Once the fault is cleared, replace the blown fuse with a new Littelfuse FLNR045 fuse. Ensure the replacement fuse has the exact same ratings.
- Re-energize and Monitor: Restore power and monitor the circuit for proper operation. If the new fuse blows immediately, there is still an unresolved issue in the circuit that requires professional attention.
Do not repeatedly replace fuses without addressing the underlying problem, as this can lead to serious electrical hazards.
8. ข้อมูลจำเพาะ
| ข้อมูลจำเพาะ | ค่า |
|---|---|
| หมายเลขรุ่น | FLNR045 |
| ยี่ห้อ | ลิตเทิลฟิวส์ |
| เล่มที่tage เรตติ้ง | AC 250 โวลต์ |
| Ampเรจเรตติ้ง | 45 Amps |
| คลาสฟิวส์ | RK5 |
| ลักษณะเด่น | Time-Delay, Dual-Element |
| วัสดุ | Stone (Insulating Body) |
| การปฏิบัติตาม | ได้รับการรับรองจาก UL |
| หมวดหมู่ | Panel Accessories, Fuse |
9. การรับประกันและการสนับสนุน
For information regarding warranty, technical support, or service for your Littelfuse FLNR045 fuse, please contact Littelfuse directly through their official website or customer service channels. Keep your purchase receipt for any warranty claims.
Littelfuse Official Webเว็บไซต์: www.littelfuse.com





