Littelfuse 0251003.NAT1L Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0251003.NAT1L is a 3 A, 125 V AC/DC board mount fuse with axial through-hole configuration, part of the PICO® II 251 series. This fast-blow fuse is designed for circuit protection in applications requiring reliable overcurrent interruption at rated voltage levels. The part maintains active product status with full regulatory compliance across multiple approval agencies including CCC, CSA, cURus, PSE, and TUV. Substitute parts are identified when identical electrical and mechanical specifications are maintained across different packaging or tape configurations from the same manufacturer.

Substiute Parts

0251003.NAT1L

Littelfuse Inc.In Stock: 51260251003.NAT1L Datasheet

Current PartRFQ

0251003.HAT1L

Littelfuse Inc.In Stock: 12070251003.HAT1L Datasheet

Parametric EquivalentRFQ

0251003.MAT1L

Littelfuse Inc.In Stock: 38430251003.MAT1L Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 0251003.NAT1L are identified based on strict equivalence across all critical electrical and mechanical parameters. The substitution criteria are:

• Current Rating: 3 A (exact match required)
• Voltage Rating: 125 V AC and 125 V DC (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Package / Case: Axial (exact match required)
• Breaking Capacity: 50 A AC, 300 A DC (exact match required)
• Melting I²t: 1.19 (exact match required)
• Operating Temperature Range: -55°C to 125°C (exact match required)
• DC Cold Resistance: 0.0295 Ohms (exact match required)
• Series: PICO® II 251 (exact match required)
• Regulatory Approvals: CCC, CSA, cURus, PSE, TUV (exact match required)

The identified substitutes (0251003.HAT1L and 0251003.MAT1L) meet all these criteria and differ only in packaging configuration (Cut Tape), which does not affect electrical or mechanical performance in the application.

Parameter Comparison

Engineering Selection Recommendations

All three parts (0251003.NAT1L, 0251003.HAT1L, and 0251003.MAT1L) are functionally equivalent for circuit protection applications requiring 3 A, 125 V AC/DC fast-blow fuse protection. Selection between these parts should be based on:

• Inventory availability and lead time requirements
• Packaging format compatibility with assembly processes (Cut Tape vs. standard packaging)
• Supply chain logistics and cost considerations

All parts maintain active product status and carry identical regulatory approvals (CCC, CSA, cURus, PSE, TUV), ensuring compliance with applicable standards across all intended markets. ROHS3 compliance is maintained across all substitute options.

Frequently Asked Questions (FAQ)

Q: Can 0251003.HAT1L or 0251003.MAT1L be used as direct replacements for 0251003.NAT1L?

A: Yes. These parts are parametric equivalents with identical electrical and mechanical specifications. The only difference is packaging configuration (Cut Tape), which does not affect circuit protection performance or board mount compatibility.

Q: Are there any differences in breaking capacity or response time between these parts?

A: No. All three parts have identical breaking capacity (50 A AC, 300 A DC) and fast-blow response time characteristics. They provide equivalent protection performance in the same application.

Q: Do all substitute parts carry the same regulatory approvals?

A: Yes. All parts carry CCC, CSA, cURus, PSE, and TUV approvals and are ROHS3 compliant. No compliance differences exist between the main part and substitutes.

Q: What is the significance of the different part number suffixes (NAT1L, HAT1L, MAT1L)?

A: The suffixes indicate different packaging tape configurations used during manufacturing and distribution. The electrical and mechanical specifications remain identical across all configurations.

Q: Can these parts be used in both AC and DC circuits?

A: Yes. All parts are rated for 125 V AC and 125 V DC operation, making them suitable for both AC and DC circuit protection applications within the specified voltage range.

Q: What is the operating temperature range for these fuses?

A: All parts operate across -55°C to 125°C, providing consistent performance across industrial and commercial temperature environments.