SCHURTER 0034.4285 Equivalent & Substitute Parts

Part Overview

The SCHURTER 0034.4285 is a 2.5 A 125 V AC/DC board mount radial fuse with fast blow response time, designed for through-hole applications. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The MSF 125 series fuse provides protection in low-voltage AC/DC circuits with a breaking capacity of 300 A at rated voltage.

Substiute Parts

0034.4285

SCHURTER Inc.In Stock: 7660034.4285 Datasheet

Current PartRFQ

0034.4225

SCHURTER Inc.In Stock: 12260034.4225 Datasheet

SimilarRFQ

0034.4255

SCHURTER Inc.In Stock: 11230034.4255 Datasheet

Parametric EquivalentRFQ

30312500421

Littelfuse Inc.In Stock: 84230312500421 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SCHURTER 0034.4285 is determined by the following critical parameters:

Primary Matching Criteria:

• Current Rating: 2.5 A (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)
• Package / Case: Radial, Can (exact match required)

Secondary Compatibility Factors:

• Size / Dimension: 0.252" Dia x 0.346" H (6.40mm x 8.80mm) - physical fit requirement
• Melting I²t: 0.6 - thermal response characteristic
• Operating Temperature Range: -25°C ~ 85°C - environmental suitability

The SCHURTER 0034.4225 and 0034.4255 are direct parametric equivalents from the same manufacturer and series (MSF 125), matching all primary criteria. Both parts are active products with current availability, providing reliable alternatives to the obsolete 0034.4285.

The Littelfuse 30312500421 is a similar substitute with the same current rating and AC voltage rating. However, this part has a reduced DC voltage rating (63 V versus 125 V), lower breaking capacity (50 A versus 300 A), different melting I²t (0.23 versus 0.6), smaller physical dimensions (0.236" Dia x 0.315" H), and a narrower operating temperature range (-25°C ~ 70°C). This part is suitable only for applications where the lower DC voltage and reduced breaking capacity are acceptable.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents):

The SCHURTER 0034.4225 and 0034.4255 are the preferred substitutes for the obsolete 0034.4285. Both parts are active products from the same manufacturer and MSF 125 series, with identical electrical specifications and physical dimensions. Both maintain ROHS3 compliance and cURus approval. The 0034.4225 is available in bulk packaging with 1171 units in stock, while the 0034.4255 is also available in bulk with 1079 units in stock. Either part provides direct functional replacement without design modification.

Alternative Substitute (Reduced Specifications):

The Littelfuse 30312500421 is an active product suitable only for applications where the reduced DC voltage rating (63 V), lower breaking capacity (50 A), and narrower operating temperature range (-25°C ~ 70°C) are acceptable. This part has different physical dimensions and a lower melting I²t value (0.23), indicating faster thermal response. The part carries CSA and UL approvals and maintains ROHS3 compliance. Use this substitute only when circuit requirements do not demand the full 125 V DC rating or 300 A breaking capacity of the original part.

Frequently Asked Questions (FAQ)

Q: Can the SCHURTER 0034.4225 or 0034.4255 be used as direct replacements for the 0034.4285?

A: Yes. Both parts are parametric equivalents with identical current rating (2.5 A), AC/DC voltage ratings (125 V), response time (Fast Blow), mounting type (Through Hole), and physical dimensions (0.252" Dia x 0.346" H). Both are active products with current manufacturing and inventory availability.

Q: What is the difference between the 0034.4225 and 0034.4255?

A: Both parts are electrically and mechanically identical. The primary difference is packaging: 0034.4225 is supplied in bulk packaging, while 0034.4255 is also supplied in bulk packaging. Both are from the SCHURTER MSF 125 series with identical specifications and availability.

Q: Can the Littelfuse 30312500421 replace the SCHURTER 0034.4285 in all applications?

A: No. The Littelfuse part has a reduced DC voltage rating (63 V versus 125 V), lower breaking capacity (50 A versus 300 A), and different physical dimensions (0.236" Dia x 0.315" H versus 0.252" Dia x 0.346" H). Use this part only in applications where these reduced specifications are acceptable.

Q: Are all substitute parts RoHS compliant?

A: Yes. The SCHURTER 0034.4225, 0034.4255, and Littelfuse 30312500421 are all ROHS3 compliant, matching the compliance status of the original 0034.4285.

Q: What are the approval agencies for these fuses?

A: The SCHURTER parts (0034.4225 and 0034.4255) carry cURus approval. The Littelfuse 30312500421 carries CSA and UL approvals. All parts meet recognized safety standards for board mount fuses.

Q: Do the substitute parts have the same physical footprint?

A: The SCHURTER 0034.4225 and 0034.4255 have identical dimensions (0.252" Dia x 0.346" H) to the original 0034.4285 and will fit existing PCB layouts without modification. The Littelfuse 30312500421 has smaller dimensions (0.236" Dia x 0.315" H) and may require PCB layout verification for proper fit.

Q: What is the melting I²t specification and why does it matter?

A: Melting I²t represents the thermal energy required to melt the fuse element. The SCHURTER parts have a melting I²t of 0.6, while the Littelfuse part has 0.23. A lower value indicates faster thermal response. For the original application, the SCHURTER parts with matching I²t values are preferred.