30R900UMR

Ptc Resettable Fuses Overview

The Littelfuse 30R900UMR is a POLYFUSE resettable PTC device from the 30R series, designed for through-hole PCB mounting. It features radial leads with a 10.20 mm spacing and operates within a temperature range of -40°C to +85°C. The component has a maximum voltage rating of 30V and a hold current (Ih) of 9 A. Trip current (It) is specified at 18 A, with a maximum fault current rating of 40 A. Initial resistance (Ri) is minimum 5 mOhms, while post-trip resistance (R1) is maximum 20 mOhms. Dimensions are 24.10 mm in length, 3.00 mm in width, and up to 31.60 mm in height.

Ptc Resettable Fuses Feature Summary

• Provides automatic circuit protection by increasing resistance significantly upon overcurrent conditions
• Designed for applications where space constraints are not critical and resettable functionality is required
• Features a polymer construction suitable for through-hole radial leaded mounting on printed circuit boards

Ptc Resettable Fuses Applications

• Overcurrent protection for electronic circuits requiring resettable fuse solutions
• Protection of sensitive components against transient overcurrent events
• Circuit safeguarding in industrial or commercial equipment utilizing through-hole assembly

Ptc Resettable Fuses Procurement Notes

Verify that the specific suffix UMR corresponds to the required tape-and-reel packaging configuration rather than bulk or other formats. Confirm that the 30V maximum voltage and 9 A hold current align with the target circuit's operational parameters. Ensure the 10.20 mm lead spacing fits the designated PCB footprint. Check RoHS 3 compliance status if environmental regulations apply to the final product assembly.

Ptc Resettable Fuses Selection Notes

Select this component when the application requires a high-current resettable fuse with a 30V rating. The 9 A hold current makes it suitable for protecting higher-power circuits compared to lower-rated variants. Consider the physical dimensions, particularly the 31.60 mm height, to ensure adequate clearance on the PCB. Verify that the trip current of 18 A provides appropriate margin above normal operating currents without nuisance tripping.

Ptc Resettable Fuses Part Context

This part belongs to the Littelfuse 30R series of POLYFUSE resettable PTC devices. The series is characterized by radial leaded packages intended for through-hole mounting. These devices offer a balance of high current handling and resettable protection, distinguishing them from single-use fuses. The 30R series is generally used where space is less constrained than in surface-mount applications.

Ptc Resettable Fuses Replacement Considerations

Compatible substitutes include other 30R series parts with matching electrical ratings, such as 30R900MPR or 30R900UF, provided the packaging type (tape vs. bulk) and lead spacing requirements are met. Ensure any replacement maintains the same 30V max voltage and 9 A hold current specifications.