SCHURTER 0034.4270 Equivalent & Substitute Parts

Part Overview

The SCHURTER 0034.4270 is a 125 mA, 125 V AC/DC board mount fuse with fast blow response time, housed in a radial can package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new designs. The MSF 125 series fuse is designed for through-hole mounting applications requiring reliable overcurrent protection in low-voltage circuits.

Substiute Parts

0034.4270

SCHURTER Inc.In Stock: 10620034.4270 Datasheet

Current PartRFQ

0034.4210

SCHURTER Inc.In Stock: 9150034.4210 Datasheet

Parametric EquivalentRFQ

0034.4240

SCHURTER Inc.In Stock: 9710034.4240 Datasheet

Parametric EquivalentRFQ

0273.125H

Littelfuse Inc.In Stock: 9720273.125H Datasheet

DirectRFQ

0272.125V

Littelfuse Inc.In Stock: 10130272.125V Datasheet

SimilarRFQ

0273.125V

Littelfuse Inc.In Stock: 8920273.125V Datasheet

SimilarRFQ

30301250421

Littelfuse Inc.In Stock: 96530301250421 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SCHURTER 0034.4270 is determined by the following critical parameters:

Primary Substitution Criteria:

• Current Rating: 125 mA (exact match required)
• Voltage Rating - AC: 125 V (exact match required)
• Voltage Rating - DC: 125 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Fuse Type: Board Mount (Cartridge Style Excluded) (exact match required)

Secondary Compatibility Factors:

• Package / Case: Radial, Can (physical footprint compatibility)
• Size / Dimension: Nominal equivalence within manufacturing tolerances
• Operating Temperature Range: Must accommodate application requirements
• Approval Agency: Compliance certifications for target markets

Substitute parts are grouped into three categories:

Parametric Equivalents (SCHURTER 0034.4210, 0034.4240): Identical electrical specifications and mounting characteristics. These parts share the same series (MSF 125), current rating, voltage ratings, and response time. Primary difference is product status (active vs. obsolete) and breaking capacity variance.

Direct Manufacturer Equivalent (Littelfuse 0273.125H): Matches all critical electrical parameters and mounting type. Offers superior breaking capacity (10kA) and expanded temperature range (-55°C ~ 85°C). Vertical orientation package provides mechanical compatibility with radial can footprint.

Similar Alternatives (Littelfuse 0272.125V, 0273.125V, Littelfuse 30301250421): Meet core electrical specifications (125 mA, 125 V AC, fast blow, through-hole board mount) with dimensional or voltage rating variations. These parts require design verification for mechanical fit and application-specific voltage requirements.

Parameter Comparison

Engineering Selection Recommendations

First Priority - Parametric Equivalents: SCHURTER 0034.4210 and 0034.4240 are the preferred substitutes. Both parts maintain identical electrical specifications, current rating, voltage ratings, and response characteristics as the original 0034.4270. These parts are active products with current manufacturing support and cURus certification. The primary distinction between these two SCHURTER options is packaging (bulk) and breaking capacity (100A vs. 300A original). For applications where the 300A breaking capacity of the original part is not a design requirement, either SCHURTER substitute provides direct functional replacement.

Secondary Priority - Direct Manufacturer Equivalent: Littelfuse 0273.125H offers enhanced performance characteristics while maintaining all critical electrical parameters. This part provides 10kA breaking capacity and extended low-temperature operation (-55°C minimum vs. -25°C original). The vertical orientation package is mechanically compatible with radial can footprint applications. Littelfuse certification includes CSA, QPL, and UL approvals, providing broader market compliance than the original cURus certification.

Tertiary Options - Similar Alternatives: Littelfuse 0272.125V and 0273.125V meet core electrical specifications with dimensional variations. The 0272.125V operates across an extended temperature range (-55°C ~ 125°C) and features a smaller physical footprint (0.235" Dia x 0.287" H). The 0273.125V matches the dimensional profile of the 0273.125H variant. Littelfuse 30301250421 is suitable only for applications where 63 V DC rating is acceptable; this part is not recommended for 125 V DC circuits.

Compliance Considerations: All substitute parts maintain ROHS3 compliance and REACH unaffected status. Littelfuse parts provide enhanced certification coverage (CSA, QPL, UL) compared to the original cURus certification, supporting broader regulatory requirements in North American and international markets.

Frequently Asked Questions (FAQ)

Q: Can SCHURTER 0034.4210 or 0034.4240 be used as direct replacements for the obsolete 0034.4270?

A: Yes. Both parts are parametric equivalents with identical current rating (125 mA), voltage ratings (125 V AC/DC), response time (fast blow), and mounting configuration (through-hole board mount). The primary difference is breaking capacity: the original part is rated 300A, while the substitutes are rated 100A. For applications not requiring 300A breaking capacity, these SCHURTER parts provide complete functional equivalence.

Q: What is the difference between the SCHURTER and Littelfuse substitute options?

A: SCHURTER 0034.4210 and 0034.4240 are parametric equivalents from the same manufacturer as the original part, ensuring design continuity. Littelfuse 0273.125H, 0272.125V, and 0273.125V are cross-manufacturer alternatives that meet electrical specifications but may require mechanical fit verification due to dimensional variations and package orientation differences. Littelfuse parts offer enhanced breaking capacity (10kA) and broader certification coverage (CSA, QPL, UL).

Q: Are there any dimensional compatibility concerns when substituting with Littelfuse parts?

A: Littelfuse 0273.125H and 0273.125V are dimensionally similar to the original part (0.250" Dia x 0.350" H vs. 0.252" Dia x 0.346" H original), with nominal tolerance variations acceptable for through-hole board mount applications. Littelfuse 0272.125V features a smaller footprint (0.235" Dia x 0.287" H) and requires verification of PCB hole spacing and component clearance. All Littelfuse options use vertical orientation packaging, compatible with radial can mounting patterns.

Q: Why is Littelfuse 30301250421 listed as a similar alternative rather than a direct substitute?

A: The 30301250421 has a reduced DC voltage rating of 63 V compared to the original 125 V DC specification. This part is suitable only for applications operating at 63 V DC or lower. For circuits requiring full 125 V DC operation, this part is not compatible and should not be selected.

Q: What is the significance of the breaking capacity difference between the original 0034.4270 (300A) and the SCHURTER substitutes (100A)?

A: Breaking capacity defines the maximum fault current the fuse can safely interrupt without rupturing or creating a hazard. The original part's 300A rating provides margin for high-fault-current applications. The 100A rating of the SCHURTER substitutes is suitable for standard low-voltage circuit protection where fault currents do not exceed this threshold. Application circuit analysis determines whether the reduced breaking capacity is acceptable.

Q: Do all substitute parts have the same operating temperature range?

A: No. The original 0034.4270 operates from -25°C to 85°C. SCHURTER 0034.4210 and 0034.4240 match this range. Littelfuse 0273.125H and 0273.125V extend the low-temperature limit to -55°C. Littelfuse 0272.125V provides the widest range (-55°C to 125°C). Littelfuse 30301250421 is limited to -25°C to 70°C. Selection depends on application environmental requirements.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the environmental compliance profile of the original 0034.4270.