Littelfuse 0232004.M Glass Cartridge Fuse 4A 250VAC 5x20mm Equivalent & Substitute Parts

Part Overview

The Littelfuse 0232004.M is a 4A 250VAC glass cartridge fuse with a 5x20mm form factor, designed for medium-blow response applications requiring a holder for installation. This part is classified as obsolete, making identification of active equivalent and substitute components essential for ongoing system support and procurement planning. The fuse provides 100A breaking capacity at rated voltage with a melting I²t of 38.75, suitable for general-purpose circuit protection in AC and DC applications across the -55°C to 125°C operating temperature range.

Substiute Parts

0232004.M

Littelfuse Inc.In Stock: 9840232004.M Datasheet

Current PartRFQ

0232004.MXP

Littelfuse Inc.In Stock: 7780232004.MXP Datasheet

Parametric EquivalentRFQ

MSC-4A

OptiFuseIn Stock: 4224MSC-4A Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 0232004.M is determined by strict equivalence across the following parameters: current rating (4A), voltage rating (250VAC), fuse type (cartridge glass), physical package (5x20mm), response time (medium blow), and mounting configuration (requires holder). All identified substitutes maintain these core electrical and mechanical specifications, ensuring direct functional replacement without circuit redesign or holder modification.

The two substitute parts identified—0232004.MXP (Littelfuse) and MSC-4A (OptiFuse)—meet all substitution criteria. Differences in melting I²t values (37.73 and 33.47 respectively, compared to 38.75 for the main part) and DC cold resistance remain within acceptable tolerance ranges for this component category and do not preclude substitution.

Parameter Comparison

Engineering Selection Recommendations

For new designs and ongoing procurement, the Littelfuse 0232004.MXP is the primary recommended substitute. It maintains identical electrical and mechanical specifications to the obsolete 0232004.M while offering active product status and ROHS3 compliance. The 0232004.MXP carries CE, KC, and PSE approvals, providing broader regulatory coverage than the original part.

The OptiFuse MSC-4A serves as a secondary substitute option. It meets all core electrical and mechanical requirements and maintains active product status with ROHS3 compliance and cULus/UL 248 certifications. The MSC-4A exhibits a lower melting I²t value (33.47 versus 38.75), which may result in faster response characteristics in certain circuit conditions but remains within acceptable substitution parameters for this fuse category.

Selection between 0232004.MXP and MSC-4A should be based on supply chain availability, certification requirements specific to the end application, and any design-specific thermal response preferences.

Frequently Asked Questions (FAQ)

Q: Can the 0232004.MXP directly replace the obsolete 0232004.M without circuit modification?

A: Yes. The 0232004.MXP maintains identical current rating (4A), voltage rating (250VAC), physical dimensions (5x20mm), response time (medium blow), and mounting configuration (requires holder). No circuit redesign or holder replacement is necessary.

Q: What is the significance of the different melting I²t values among the three fuses?

A: Melting I²t indicates the thermal energy required to melt the fuse element. The 0232004.M (38.75), 0232004.MXP (37.73), and MSC-4A (33.47) all operate within acceptable ranges for 4A medium-blow cartridge fuses. The variation reflects different internal element designs but does not affect substitutability for standard circuit protection applications.

Q: Are there compliance differences between the substitute parts?

A: Yes. The 0232004.M is RoHS non-compliant. Both 0232004.MXP and MSC-4A are ROHS3 compliant. The 0232004.MXP carries CE, KC, and PSE approvals, while MSC-4A carries cULus and UL 248 certifications. Selection should align with the regulatory requirements of the target application and market.

Q: Will the MSC-4A work in the same holder as the 0232004.M?

A: Yes. The MSC-4A shares the identical 5x20mm form factor and requires the same holder type as the 0232004.M. Physical installation is interchangeable.

Q: What inventory considerations should guide part selection?

A: The 0232004.MXP has 687 units in stock, while MSC-4A has 4,176 units available. For applications requiring immediate procurement or high-volume orders, MSC-4A availability may provide supply chain advantages.