SL321R030

Overview

The Vishay Ametherm SL321R030 is a radial leaded Negative Temperature Coefficient (NTC) thermistor designed as an inrush current limiter. It features a nominal resistance of 1 Ohm with a tolerance of ±20% and a maximum steady-state current rating of 30 A. The component supports multiple voltage ratings including 120 VAC, 240 VAC, 480 VAC, and 680 VAC. Physically, it has a diameter of approximately 32 mm (specifically 31.00 mm or 1.220 inches), a pitch spacing of 3.82 mm, and a dissipation factor of 45.4 mW/C.

Feature Summary

• Provides effective suppression of high inrush currents during power-up sequences to protect downstream electronic components.
• Utilizes NTC thermistor technology where resistance decreases significantly as temperature rises, allowing efficient conduction after initial limiting.
• Designed for robust PCB mounting with radial leads suitable for through-hole assembly processes.

Applications

• Power supply input stages
• Motor drive circuits
• Transformer protection

Procurement Notes

Verify the specific datasheet version for precise thermal characteristics and derating curves. Confirm that the 30 A current rating aligns with your application's peak load requirements. Ensure the PCB layout accommodates the 3.82 mm lead spacing and the physical footprint of the 32 mm disc. Check RoHS compliance status if required by your manufacturing standards.

Selection Notes

Select this component when a 1 Ohm cold resistance is appropriate for the target circuit impedance. The 30 A rating suits applications requiring moderate surge handling. Consider the dissipation factor for thermal management in enclosed environments. Compare against the AS32 series if different physical dimensions are needed for the same electrical specifications.

Part Context

This part belongs to the SL32 series of inrush current limiters from Vishay Ametherm. It is functionally similar to the AS321R030 but may differ in specific physical tolerances or packaging details. The SL32 series is widely used for general-purpose surge protection in AC and DC power systems.

Replacement Considerations

The AS321R030 is a closely related part within the Vishay portfolio. Verify dimensional compatibility before substitution, as lead spacing and body diameter may vary slightly between the SL32 and AS32 series despite similar electrical ratings.