RUEF900

Ptc Resettable Fuses Overview

The Littelfuse RUEF900K is a PolySwitch radial-leaded PPTC resettable fuse designed for PCB mounting. It features a hold current of 9 A and a trip current of 18 A, with a maximum voltage rating of 30 VDC. The device has a maximum fault current rating (Imax) of 40 A and a minimum resistance of 20 mOhms. Operating within a temperature range of -40°C to +85°C, it dissipates up to 4.2 W. Physical dimensions include a length of 29 mm, width of 24.1 mm, height of 3 mm, and a lead spacing of 10.9 mm.

Ptc Resettable Fuses Feature Summary

• Provides reliable overcurrent protection by increasing resistance as heat limits current flow
• Offers automatic reset functionality after fault conditions clear
• Designed for radial leaded through-hole PCB mounting

Ptc Resettable Fuses Applications

• Protection for automotive actuators and small motors
• Overcurrent safeguarding for telecom equipment circuits
• Power supply circuit protection in industrial systems

Ptc Resettable Fuses Procurement Notes

Verify the specific ordering suffix against the manufacturer datasheet to confirm packaging type and electrical tolerances. Ensure the selected variant matches the required Imax rating and lead spacing for the target PCB layout. Confirm RoHS compliance status and lead-free soldering compatibility prior to integration into the final assembly design.

Ptc Resettable Fuses Selection Notes

Select this component when a high-current resettable fuse is required for low-voltage DC applications. The 9 A hold current suits heavy-duty loads where standard fuses would nuisance-trip. Verify that the 30 VDC rating aligns with the system voltage and that the 40 A Imax capability exceeds potential short-circuit currents in the protected branch.

Ptc Resettable Fuses Part Context

This part belongs to the RUEF series of PolySwitch resettable fuses from Littelfuse. These devices are solid-state polymer components used for circuit protection. The RUEF series specifically targets high-current applications requiring robust overcurrent defense in automotive, telecom, and power supply environments.

Ptc Resettable Fuses Replacement Considerations

RUEF900-2 serves as an alternative variant within the same series, offering identical electrical specifications but differing in packaging format.