SCHURTER 0034.4280 Board Mount Fuse — Equivalent & Substitute Parts

Part Overview

The SCHURTER 0034.4280 is an 800 mA, 125 V AC/DC board mount fuse in radial, can package format, designed for through-hole PCB mounting. This part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for ongoing production and field replacement applications.

Key Parameters

Parameter	Value
Current Rating	800 mA
Voltage Rating (AC)	125 V
Voltage Rating (DC)	125 V
Fuse Type	Board Mount (Cartridge Style Excluded)
Mounting Type	Through Hole
Package / Case	Radial, Can
Response Time	Fast Blow
Operating Temperature Range	-25°C ~ 85°C
Size / Dimension	0.252" Dia x 0.346" H (6.40mm x 8.80mm)
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility for the SCHURTER 0034.4280 is determined by strict equivalence across the following parameters:

Current Rating: 800 mA (exact match required)
Voltage Rating (AC): 125 V (exact match required)
Voltage Rating (DC): 125 V (exact match required)
Fuse Type: Board Mount (Cartridge Style Excluded)
Mounting Type: Through Hole
Package / Case: Radial, Can
Response Time: Fast Blow
RoHS Compliance: ROHS3 Compliant

Substitute parts are grouped into two categories:

Category 1: Parametric Equivalents (SCHURTER Series) Parts 0034.4220 and 0034.4250 are SCHURTER MSF 125 series fuses meeting all electrical parameters. Both are active products with identical current, voltage, and response characteristics. Mechanical dimensions and package format are identical.

Category 2: Direct and Similar Equivalents (Littelfuse Series) Parts 0273.800V, 0272.800V, and 0278.800V are Littelfuse MICRO™ series fuses meeting all electrical parameters. Part 30308000421 (Littelfuse TR3® 303) shares current rating and AC voltage but operates at reduced DC voltage (63 V DC) and is listed as a similar equivalent only.

Parameter Comparison

Parameter	0034.4280 (Main)	0034.4220	0034.4250	0273.800V	0272.800V	0278.800V	30308000421
Manufacturer	SCHURTER Inc.	SCHURTER Inc.	SCHURTER Inc.	Littelfuse Inc.	Littelfuse	Littelfuse Inc.	Littelfuse Inc.
Series	MSF 125	MSF 125	MSF 125	MICRO™ 273	MICRO™ 272	MICRO™ 278	TR3® 303
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
Current Rating (Amps)	800 mA	800 mA	800 mA	800 mA	800 mA	800 mA	800 mA
Voltage Rating - AC	125 V	125 V	125 V	125 V	125 V	125 V	125 V
Voltage Rating - DC	125 V	125 V	125 V	125 V	125 V	125 V	63 V
Response Time	Fast Blow	Fast Blow	Fast Blow	Fast Blow	Fast Blow	Fast Blow	Fast Blow
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Fuse Type	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)	Board Mount (Cartridge Style Excluded)
Package / Case	Radial, Can	Radial, Can	Radial, Can	Radial, Can, Vertical	Radial, Can, Vertical	Radial, Can, Vertical	Radial, Can, Vertical
Size / Dimension	0.252" Dia x 0.346" H (6.40mm x 8.80mm)	0.252" Dia x 0.346" H (6.40mm x 8.80mm)	0.252" Dia x 0.346" H (6.40mm x 8.80mm)	0.250" Dia x 0.350" H (6.35mm x 8.89mm)	0.235" Dia x 0.287" H (5.97mm x 7.30mm)	0.235" Dia x 0.287" H (5.97mm x 7.30mm)	0.236" Dia x 0.315" H (6.00mm x 8.00mm)
Operating Temperature Range	-25°C ~ 85°C	-25°C ~ 85°C	-25°C ~ 85°C	-55°C ~ 85°C	-55°C ~ 125°C	-55°C ~ 125°C	-25°C ~ 70°C
Breaking Capacity @ Rated Voltage	300A	100A	100A	10kA	10kA	10kA	50A
Melting I²t	0.04	0.04	0.04	0.113	0.113	0.113	0.025
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	cURus	cURus	cURus	CSA, QPL, UL	CSA, QPL, UL	CSA, QPL, UL	CSA, UL

Engineering Selection Recommendations

Primary Substitutes (Recommended for Direct Replacement)

SCHURTER 0034.4220 and 0034.4250 are the preferred substitutes. Both are active products within the same MSF 125 series, maintaining identical electrical specifications, mechanical dimensions, and operating temperature range as the obsolete 0034.4280. Both carry cURus approval and ROHS3 compliance. The 0034.4250 offers higher inventory availability (1157 pcs) compared to 0034.4220 (759 pcs).

Secondary Substitutes (Cross-Manufacturer Alternatives)

Littelfuse MICRO™ series parts 0273.800V, 0272.800V, and 0278.800V provide electrical equivalence with enhanced breaking capacity (10kA vs. 300A) and extended operating temperature ranges. These parts carry CSA, QPL, and UL certifications. Mechanical dimensions vary slightly; PCB footprint compatibility must be verified during design review.

Limited Compatibility Substitute

Littelfuse 30308000421 (TR3® 303) shares the 800 mA current rating and 125 V AC voltage but operates at reduced DC voltage (63 V DC). This part is suitable only for applications where DC voltage does not exceed 63 V. Approval agencies are CSA and UL (no QPL listing).

Frequently Asked Questions (FAQ)

Q: Can SCHURTER 0034.4220 or 0034.4250 be used as direct replacements for the obsolete 0034.4280?

A: Yes. Both parts are parametric equivalents with identical current rating (800 mA), voltage ratings (125 V AC/DC), response time (Fast Blow), mounting type (Through Hole), and package format (Radial, Can). Mechanical dimensions and operating temperature ranges are identical. Both are active products with current manufacturing support.

Q: What is the difference between SCHURTER and Littelfuse substitutes?

A: SCHURTER 0034.4220 and 0034.4250 maintain identical specifications and dimensions as the original part. Littelfuse MICRO™ series (0273.800V, 0272.800V, 0278.800V) offer higher breaking capacity and extended temperature ranges but have slightly different physical dimensions. Littelfuse parts carry additional certifications (QPL, UL) beyond the cURus approval of SCHURTER parts.

Q: Are there any mechanical compatibility concerns with Littelfuse substitutes?

A: Littelfuse MICRO™ 272 and 278 series have reduced diameter (0.235" vs. 0.252") and height (0.287" vs. 0.346"). MICRO™ 273 dimensions are closer to the original (0.250" Dia x 0.350" H). PCB footprint hole spacing and clearance must be verified before implementation.

Q: Can Littelfuse 30308000421 be used in all applications?

A: No. This part operates at 63 V DC maximum, compared to 125 V DC for the original part. Use only in applications where DC voltage does not exceed 63 V. The reduced melting I²t (0.025 vs. 0.04) and lower breaking capacity (50A vs. 300A) also indicate different thermal and electrical characteristics.

Q: What certifications apply to each substitute?

A: SCHURTER 0034.4220 and 0034.4250 carry cURus approval. Littelfuse MICRO™ series (0273.800V, 0272.800V, 0278.800V) carry CSA, QPL, and UL certifications. Littelfuse 30308000421 carries CSA and UL certifications. All parts are ROHS3 compliant and REACH unaffected.

Q: Which substitute offers the best inventory availability?

A: SCHURTER 0034.4250 has the highest inventory (1157 pcs), followed by Littelfuse 0278.800V (1038 pcs) and Littelfuse 30308000421 (857 pcs).

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message