Introduction
This manual provides essential information for the safe and effective use of the Littelfuse FLNR-35 Class RK5 Dual Element Fuse. This fuse is designed to provide reliable overcurrent protection in various electrical circuits. Please read this manual thoroughly before installation or operation.
Safety Information
WARNING: Electrical shock hazard. Improper installation or use can result in serious injury or death. Always disconnect power before working with electrical components.
- Ensure all power to the circuit is disconnected at the main service panel before handling fuses.
- Only qualified personnel should install or replace fuses.
- Always replace a blown fuse with a fuse of the same type, voltage rating, and ampere rating (e.g., FLNR-35 with another FLNR-35).
- Do not bypass or tamper with fuses.
- Wear appropriate personal protective equipment (PPE), such as insulated gloves and safety glasses, when working with electrical systems.
Specifications
| Specification | Value |
|---|---|
| Model Number | FLNR-35 |
| Brand | Littelfuse |
| Voltage Rating | 250 Volts |
| Current Rating | 35 Amps |
| Class | RK5 |
| Element Type | Dual Element |
| Material | Copper |
| Dimensions (L x W x H) | 3 x 0.72 x 3 inches |
| Weight | 0.798 ounces |
| Mounting Type | Through-Hole Mount |
| Compliance | UL Listed |
Installation
- Power Disconnection: Before beginning any installation, ensure that the main power supply to the circuit where the fuse will be installed is completely disconnected and locked out according to safety procedures. Verify with a voltage tester.
- Fuse Holder Preparation: Ensure the fuse holder or disconnect switch is clean and free from debris. The holder must be rated for the FLNR-35 fuse's voltage and current.
- Fuse Insertion: Carefully insert the FLNR-35 fuse into the appropriate fuse clips or holder. Ensure a firm and secure connection. Do not force the fuse.
- Verification: Double-check that the fuse is correctly seated and that all connections are tight.
- Power Restoration: Once installation is complete and verified, restore power to the circuit.
Note: It is highly recommended that installation be performed by a qualified electrician to ensure compliance with local electrical codes and safety standards.
Operation
The Littelfuse FLNR-35 is a passive protective device. It operates by interrupting the electrical circuit when an overcurrent condition (e.g., short circuit or overload) occurs. The dual-element design provides both short-circuit and time-delay overload protection, allowing for temporary inrush currents without nuisance tripping, while still reacting quickly to severe short circuits.
When an overcurrent condition exceeds the fuse's rating, the internal element melts, creating an open circuit and preventing damage to downstream equipment or wiring. The fuse itself is consumed in this process and must be replaced.
Maintenance
Fuses generally require no maintenance under normal operating conditions. The primary maintenance task involves replacement after a fuse has blown.
Fuse Replacement Procedure:
- Disconnect Power: Absolutely ensure that all power to the circuit is disconnected and verified before attempting to remove or replace a fuse.
- Identify Blown Fuse: Visually inspect the fuse for signs of a blown element (e.g., darkened window, broken filament). If a visual indicator is not present, use a multimeter to test for continuity across the fuse. A blown fuse will show infinite resistance (open circuit).
- Remove Old Fuse: Carefully remove the blown fuse from its holder using an appropriate fuse puller tool. Do not use bare hands.
- Install New Fuse: Insert a new Littelfuse FLNR-35 fuse into the holder, ensuring it is securely seated. Crucially, always replace with a fuse of identical type, voltage, and ampere rating.
- Restore Power: Once the new fuse is installed and verified, restore power to the circuit.
Troubleshooting
The primary "troubleshooting" for a fuse involves identifying why it blew and replacing it correctly.
- Fuse Blows Immediately After Replacement: This indicates a persistent short circuit or severe overload in the circuit. Do not replace the fuse again until the underlying electrical fault is identified and corrected by a qualified electrician.
- Fuse Blows Intermittently: This could be due to intermittent overloads, loose connections, or a component drawing excessive current. Professional electrical inspection is recommended.
- Equipment Not Functioning (Fuse Appears Intact): Verify the fuse continuity with a multimeter. If the fuse is good, the issue lies elsewhere in the circuit or equipment.
Never install a fuse with a higher ampere rating than specified, as this can lead to severe damage to equipment or fire hazards.
Warranty Information
For specific warranty terms and conditions related to the Littelfuse FLNR-35 fuse, please refer to the official Littelfuse website or contact their customer service directly. Warranty coverage typically applies to manufacturing defects under normal use.
Customer Support
If you have questions or require technical assistance regarding the Littelfuse FLNR-35 fuse, please contact Littelfuse customer support through their official website or the contact information provided on their packaging.
Official Littelfuse Website: www.littelfuse.com