3SBP 1.25 Equivalent & Substitute Parts

Part Overview

The 3SBP 1.25 is a 1.25 A, 250 V AC/DC slow-blow glass cartridge fuse in 3AB/3AG package format (1/4" x 1-1/4" axial). Manufactured by Bel Fuse Inc., this through-hole fuse is designed for circuit protection in industrial and commercial applications. The product is currently obsolete, making identification of compatible substitute parts essential for maintenance, repair, and legacy system support. Active equivalent models from Littelfuse Inc. provide direct functional replacement while maintaining identical electrical and mechanical specifications.

Substiute Parts

3SBP 1.25

Bel Fuse Inc.In Stock: 9143SBP 1.25 Datasheet

Current PartRFQ

03151.25HXP

Littelfuse Inc.In Stock: 105303151.25HXP Datasheet

DirectRFQ

03151.25MXP

Littelfuse Inc.In Stock: 102603151.25MXP Datasheet

DirectRFQ

03151.25VXP

Littelfuse Inc.In Stock: 78203151.25VXP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3SBP 1.25 are qualified based on the following critical parameters:

• Current Rating: 1.25 A (exact match required)
• Voltage Rating: 250 V AC (exact match required)
• Fuse Type: Cartridge, Glass (exact match required)
• Response Time: Slow Blow (exact match required)
• Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (Axial) (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity: 100 A @ rated voltage (exact match required)
• Approval Agencies: CE, CSA, PSE, UL (exact match required)

All three Littelfuse Inc. substitute parts (03151.25HXP, 03151.25MXP, 03151.25VXP) meet these criteria and are functionally equivalent to the obsolete 3SBP 1.25.

Parameter Comparison

Engineering Selection Recommendations

All three Littelfuse substitute parts (03151.25HXP, 03151.25MXP, 03151.25VXP) provide direct functional equivalence to the obsolete 3SBP 1.25. Selection among these three active alternatives should be based on the following factors:

Product Status: The 3SBP 1.25 is obsolete. All three Littelfuse alternatives are active products with current manufacturing and availability.

Compliance: The Littelfuse substitutes are ROHS3 compliant, whereas the original 3SBP 1.25 is RoHS non-compliant. This compliance improvement is significant for new designs and systems subject to RoHS regulations.

Certifications: All substitute parts maintain identical approval agency certifications (CE, CSA, PSE, UL), ensuring regulatory compliance across industrial and commercial applications.

Electrical Performance: Minor variations exist in melting I²t (24 vs. 25.4) and DC cold resistance (0.26 vs. 0.35 Ohms). These differences are within acceptable tolerance for slow-blow fuse operation and do not affect circuit protection performance at the specified 1.25 A rating.

Availability: All three Littelfuse parts are in active stock with quantities exceeding 700 units, providing reliable supply for replacement and maintenance applications.

Frequently Asked Questions (FAQ)

Q: Can the Littelfuse 03151.25HXP, 03151.25MXP, or 03151.25VXP be used as direct replacements for the obsolete 3SBP 1.25?

A: Yes. All three Littelfuse parts are direct functional equivalents. They share identical current rating (1.25 A), voltage rating (250 V AC), fuse type (cartridge, glass), response time (slow blow), package format (3AB/3AG, 1/4" x 1-1/4" axial), mounting type (through hole), breaking capacity (100 A), operating temperature range (-55°C ~ 125°C), and approval certifications (CE, CSA, PSE, UL).

Q: What are the differences between the three Littelfuse substitute parts?

A: The 03151.25HXP, 03151.25MXP, and 03151.25VXP are functionally identical in all critical electrical and mechanical parameters. The part number suffix designates internal manufacturing or packaging variations that do not affect circuit protection performance or compatibility.

Q: Are there any compatibility concerns when substituting these parts?

A: No compatibility concerns exist. The substitute parts maintain the same through-hole mounting configuration, axial orientation, and physical dimensions (0.275" Dia x 1.275" L) as the original 3SBP 1.25. They install directly into existing fuse holders without modification.

Q: How do the melting I²t and DC cold resistance differences affect performance?

A: The melting I²t values (24 vs. 25.4) and DC cold resistance values (0.26 vs. 0.35 Ohms) represent minor manufacturing variations within acceptable tolerance for slow-blow fuse operation. These differences do not affect the fuse's ability to protect circuits at the 1.25 A rating or its response characteristics.

Q: Are the Littelfuse substitutes RoHS compliant?

A: Yes. All three Littelfuse substitute parts (03151.25HXP, 03151.25MXP, 03151.25VXP) are ROHS3 compliant, whereas the original 3SBP 1.25 is RoHS non-compliant. This compliance improvement is beneficial for systems subject to RoHS regulations.

Q: What certifications do the substitute parts carry?

A: All three Littelfuse substitutes carry identical certifications to the original 3SBP 1.25: CE, CSA, PSE, and UL. These certifications confirm compliance with international safety and performance standards for industrial and commercial fuse applications.