LSP550

Ptc Resettable Fuses Overview

The Littelfuse LSP550 is a thermally protected Surge Protective Device (SPD) from the LSP05G series, engineered for transient overvoltage protection in outdoor and commercial LED lighting fixtures. It utilizes thermally protected varistor technology with a built-in thermal disconnect function to prevent catastrophic failure or fire hazards during extreme conditions or end-of-life scenarios. The device supports parallel-connected and series-connected options, offering high line-to-earth/ground resistance for efficient production line testing. In series configurations, it provides clear indication of thermal fault protection by disconnecting power to the luminaire, signaling the need for module replacement. This design facilitates compliance with IEEE C62.41.2 Location Category C Low exposure standards and ANSI C136.2 Enhanced Level specifications.

Ptc Resettable Fuses Feature Summary

• Built-in thermal disconnect function prevents catastrophic failure and fire hazards under extreme voltage conditions or varistor end-of-life.
• High line-to-earth/ground resistance facilitates faster production line testing.
• Series-connected option allows clear indication of thermal fault protection by disconnecting power to signal module replacement.
• Thermally protected varistor technology ensures reliable self-protection against transient overvoltages.

Ptc Resettable Fuses Applications

• Outdoor LED lighting fixtures
• Commercial LED lighting systems
• Luminaires requiring IEEE C62.41.2 Location Category C Low compliance
• Systems adhering to ANSI C136.2 Enhanced Level specifications

Ptc Resettable Fuses Procurement Notes

Verify the specific part number suffix to confirm voltage rating and lead form compatibility with your fixture design. Confirm whether the application requires parallel or series connection, as this affects the fault indication behavior. Ensure the selected variant meets the required agency approvals, such as UL 1449 recognition for 120Vac or 240Vac ratings. Cross-reference the thermal disconnect characteristics with the luminaire's safety requirements to ensure proper fault signaling functionality.

Ptc Resettable Fuses Selection Notes

Select the LSP550 when designing for outdoor or commercial LED environments subject to significant transient overvoltage risks. Choose the series-connected variant if visual or electrical fault indication via power disconnection is required for maintenance protocols. Verify that the device's thermal protection aligns with the luminaire's enclosure constraints and safety standards. Consider the high ground resistance feature if rapid production testing throughput is a priority for manufacturing operations.

Ptc Resettable Fuses Part Context

The LSP550 belongs to the LSP05G series of surge protective devices manufactured by Littelfuse. This series is specifically developed using thermally protected varistor technology to address the unique challenges of protecting LED lighting infrastructure. Unlike standard SPDs, these devices integrate thermal management to mitigate fire risks associated with varistor degradation, making them suitable for critical lighting applications where reliability and safety are paramount.

Ptc Resettable Fuses FAQ

How does the LSP550 indicate a fault condition?

In a series-connected configuration, the LSP550 indicates a thermal fault by disconnecting power to the luminaire, which signals that the SPD module requires replacement.

What safety mechanism prevents fire hazards in the LSP550?

The device incorporates a built-in thermal disconnect function that activates during extreme circumstances, such as sustaining overvoltage or varistor end-of-life, to prevent catastrophic failure and fire hazards.