Littelfuse 02351.25MXEP Equivalent & Substitute Parts

Part Overview

The Littelfuse 02351.25MXEP is a 1.25 A, 250 V AC/DC fast-blow glass cartridge fuse with axial through-hole mounting. This component is classified as Active product status and is designed for circuit protection applications requiring fast response characteristics. Substitute parts are identified when equivalent electrical ratings, mechanical dimensions, and approval certifications align with the original specification, enabling direct replacement in compatible circuit designs.

Substiute Parts

02351.25MXEP

Littelfuse Inc.In Stock: 73402351.25MXEP Datasheet

Current PartRFQ

5MFP 1.25-R

Bel Fuse Inc.In Stock: 19475MFP 1.25-R Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Littelfuse 02351.25MXEP is determined by the following criteria:

Mandatory Matching Parameters:

• Current Rating: 1.25 A
• Voltage Rating (AC): 250 V
• Fuse Type: Cartridge, Glass
• Response Time: Fast Blow
• Mounting Type: Through Hole
• Operating Temperature Range: -55°C ~ 125°C minimum
• RoHS Compliance: ROHS3 Compliant

Acceptable Variation Parameters:

• Physical dimensions within mechanical tolerance for through-hole mounting compatibility
• Breaking Capacity at rated voltage (higher values acceptable)
• Melting I²t characteristics (within fast-blow classification)
• Approval agency certifications (subset or superset of original certifications acceptable)

The Bel Fuse Inc. 5MFP 1.25-R meets all mandatory matching parameters and qualifies as a direct substitute.

Parameter Comparison

Engineering Selection Recommendations

The Bel Fuse 5MFP 1.25-R qualifies as a direct substitute for the Littelfuse 02351.25MXEP based on electrical parameter equivalence and regulatory compliance alignment. Both components maintain identical current and voltage ratings, fast-blow response characteristics, and operating temperature specifications. Both achieve ROHS3 compliance and REACH unaffected status.

Physical dimensions differ slightly: the Bel Fuse substitute measures 5.50mm diameter x 21.00mm length versus the original 5.80mm x 22.50mm. These dimensional variations remain within acceptable mechanical tolerance for standard through-hole cartridge fuse holders. The substitute exhibits higher breaking capacity (200 A versus 100 A) and marginally higher melting I²t (1.5 versus 1.085), both of which represent enhanced performance characteristics within the fast-blow classification.

Approval certifications show partial overlap: both components hold CE, CSA, and PSE certifications. The original includes KC and UL; the substitute includes cULus. Component selection should verify that the specific certifications required by the end application are present in the chosen part.

Frequently Asked Questions (FAQ)

Q: Can the Bel Fuse 5MFP 1.25-R be used directly in place of the Littelfuse 02351.25MXEP?

A: Yes, the Bel Fuse part qualifies as a direct substitute. Both components share identical electrical ratings (1.25 A, 250 V AC), fuse type (cartridge glass), response time (fast blow), and operating temperature range (-55°C to 125°C). Physical dimensions are similar and compatible with standard through-hole mounting.

Q: What are the key differences between these two parts?

A: The primary differences are manufacturer origin, physical dimensions (minor variation within tolerance), breaking capacity (200 A versus 100 A), and approval certifications. The Bel Fuse substitute offers higher breaking capacity and slightly different certification coverage (cULus versus UL/KC).

Q: Will the dimensional differences affect mounting compatibility?

A: The dimensional variation (5.50mm x 21.00mm versus 5.80mm x 22.50mm) is within acceptable tolerance for standard through-hole cartridge fuse holders. Mechanical compatibility should be verified for application-specific holder designs.

Q: Are both parts RoHS compliant?

A: Yes, both the Littelfuse 02351.25MXEP and Bel Fuse 5MFP 1.25-R are ROHS3 compliant and REACH unaffected.

Q: Which certifications does each part hold?

A: Littelfuse 02351.25MXEP holds CE, CSA, KC, PSE, and UL certifications. Bel Fuse 5MFP 1.25-R holds CE, CSA, cULus, and PSE certifications. Verify that required certifications for your application are present in the selected part.

Q: What does "fast blow" response time mean?

A: Fast-blow fuses are designed to interrupt circuits quickly when current exceeds the rated value. Both parts share this characteristic, ensuring consistent protection behavior in equivalent applications.