Q201E4

Triacs Overview

The Littelfuse Q201E4 is a fast-acting fuse belonging to the 487 series, housed in a 5x20mm ceramic body. It provides over-current protection for telecom and datacenter server power supplies requiring high-voltage DC interruption. The device features simultaneous AC and DC ratings of 420V. It supports current ratings up to 16A within its footprint. Key electrical parameters include nominal melting I²t values and resistance specific to each ampere rating. The fuse operates within a standard temperature range and holds relevant agency approvals for industrial use.

Triacs Feature Summary

• Simultaneous AC and DC voltage ratings for versatile circuit protection
• Fast-acting response with lower I²t for rapid tripping
• High-current capacity within a compact 5x20mm form factor

Triacs Applications

• Telecom power supply circuits
• Datacenter server power supplies
• High-voltage DC interrupting applications

Triacs Procurement Notes

Verify the specific amperage rating required for the target circuit when ordering, as the 487 series spans multiple current options. Confirm that the 420V AC/DC rating aligns with the system's maximum operating voltage. Check for any specific agency approval requirements mandated by the end equipment manufacturer before finalizing the component selection.

Triacs Selection Notes

Select this fuse for applications demanding both AC and DC interruption capabilities in a standard 5x20mm size. Ensure the continuous current load does not exceed the rated value. Consider the nominal melting I²t for coordination with upstream or downstream protective devices. Verify thermal derating requirements if operation occurs outside standard ambient temperatures.

Triacs Part Context

This component is part of the Littelfuse 487 series, distinguished as the first fast-acting fuse in the 5x20mm family to offer dual AC and DC ratings. It addresses the need for reliable over-current protection in modern power distribution systems where high-voltage DC interruption is critical.

Triacs Replacement Considerations

Direct replacements must match the 5x20mm dimensions, 420V AC/DC rating, and fast-acting characteristic. Verify that substitute fuses maintain comparable I²t values to ensure proper circuit coordination and protection timing.