1. Introduction and Product Overview
BOJACK high-quality organic type thermal fuses are designed to provide reliable over-temperature protection in various electrical applications. This manual provides essential information for the safe and effective use of your SF70E thermal fuses.
The SF70E thermal fuse acts as a safety device, permanently opening an electrical circuit when its internal temperature reaches a predetermined activation point. This prevents damage to appliances and potential hazards caused by overheating.
2. Product Features and Operating Principle
- High-Quality Organic Type: Utilizes a specialized organic material for precise temperature response.
- Model: SF70E
- Rated Operating Temperature: 73 ℃
- Rated Current: 10 Amperes
- Rated Voltage: 250 Volts AC
Operating Principle: The thermal fuse consists of a sliding contact, a compression spring, and a non-conductive thermal pellet made of organic material. Under normal operating conditions, current flows from one lead, through the sliding contact, and out the other lead. When the external temperature surrounding the fuse reaches or exceeds its rated operating temperature (73℃), the organic material melts. This allows the compression spring to expand, separating the sliding contact from the lead. This action permanently opens the circuit, cutting off the current and protecting the appliance from thermal overload.
Image 2.1: BOJACK SF70E Thermal Fuse packaging showing specifications.
3. Setup and Installation
Safety First: Thermal fuses are critical safety components. Installation should only be performed by qualified personnel in accordance with all local electrical codes and the appliance manufacturer's instructions. Always disconnect the power supply to the appliance before beginning any installation or replacement work.
- Power Disconnection: Ensure the main power to the appliance is completely off and locked out to prevent accidental re-energization.
- Identify Location: Locate the existing thermal fuse or the designated installation point within the appliance's circuit.
- Connection: Connect the BOJACK SF70E thermal fuse in series with the circuit requiring over-temperature protection. Ensure secure electrical connections (e.g., crimping, soldering) that can withstand the operating environment.
- Positioning: Position the thermal fuse so it can accurately sense the temperature of the component it is protecting. Avoid placing it in areas where it might be subject to external heat sources unrelated to the protected component.
- Mechanical Stress: Avoid excessive bending, pulling, or mechanical stress on the fuse body or its leads during installation.
- Verification: After installation, double-check all connections and ensure the fuse is properly secured and isolated from unintended contact.
Image 3.1: BOJACK SF70E Thermal Fuse with approximate dimensions for installation reference.
4. Maintenance
BOJACK SF70E thermal fuses are maintenance-free devices. They do not require periodic inspection, cleaning, or calibration. Once activated, a thermal fuse cannot be reset and must be replaced.
Replacement: If a thermal fuse activates, it indicates an over-temperature condition within the appliance. Before replacing the fuse, it is crucial to identify and rectify the underlying cause of the overheating. Always replace an activated thermal fuse with a new BOJACK SF70E or an equivalent fuse with identical temperature, current, and voltage ratings to ensure continued safety and proper appliance function.
5. Troubleshooting
- Fuse Blows Immediately After Replacement: This indicates a persistent over-temperature condition or a short circuit within the appliance. Do not continue to replace fuses without thoroughly diagnosing and repairing the underlying fault. Repeated fuse replacement without addressing the root cause can lead to further damage or safety hazards.
- Appliance Not Functioning (Fuse Intact): If the appliance is not working but the thermal fuse is still conductive (i.e., it has not activated), the fault lies elsewhere in the electrical circuit. The thermal fuse is specifically designed to protect against overheating, not general electrical failures.
- Appliance Overheating (Fuse Not Blown): This scenario is unlikely if the fuse is correctly installed and rated for the application. However, if suspected, verify the fuse's temperature rating and its installation location. Ensure that the appliance has adequate ventilation and that no external factors are causing localized overheating that the fuse cannot detect.
6. Specifications
| Specification | Value |
|---|---|
| Manufacturer | BOJACK |
| Model Number | SF70E / BJ-SF-70E |
| Rated Operating Temperature | 73 ℃ |
| Rated Current | 10 Amperes |
| Rated Voltage | 250 Volts AC |
| Material | Metal |
| Mounting Type | Surface Mount |
| Package Dimensions | 6.81 x 5.11 x 1.4 cm |
| Item Weight | 18 g (for 10-pack) |
7. Warranty and Support
Warranty Information: Specific warranty details for BOJACK SF70E thermal fuses may vary depending on the retailer and region of purchase. Please refer to the documentation provided by your point of purchase or visit the official BOJACK website for the most current warranty policy.
Technical Support: For technical assistance, product inquiries, or further information regarding BOJACK products, please contact BOJACK customer service through their official website or the contact channels provided by your retailer.