SR-5-400MA-AP Equivalent & Substitute Parts

Part Overview

The SR-5-400MA-AP is a 400 mA, 250 V AC/DC board mount fuse manufactured by Eaton - Electronics Division. This through-hole radial fuse features slow-blow response characteristics and is designed for vertical mounting in radial, can-style packages. The part is currently classified as obsolete, making equivalent substitute components necessary for ongoing production support, maintenance, and new design implementations where this specification is required.

Substiute Parts

SR-5-400MA-AP

Eaton - Electronics DivisionIn Stock: 847SR-5-400MA-AP Datasheet

Current PartRFQ

37204000001

Littelfuse Inc.In Stock: 199537204000001 Datasheet

DirectRFQ

MRT 400-AMMO

Bel Fuse Inc.In Stock: 904MRT 400-AMMO Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SR-5-400MA-AP are qualified based on the following critical parameters that must match or exceed the main part specifications:

Mandatory Matching Parameters:

• Current Rating: 400 mA
• Voltage Rating (AC): 250 V
• Response Time: Slow Blow
• Mounting Type: Through Hole
• Fuse Type: Board Mount (Cartridge Style Excluded)
• Package / Case: Radial, Can, Vertical

Allowable Variation Parameters:

• Breaking Capacity @ Rated Voltage: Substitute parts may exceed the minimum 35 A requirement
• Operating Temperature Range: Substitute parts may provide extended temperature ranges
• DC Cold Resistance: Minor variations acceptable within engineering tolerance
• Melting I²t: Variations acceptable provided electrical performance remains within fuse coordination requirements
• Physical Dimensions: Minor dimensional variations acceptable provided mechanical fit is maintained within standard PCB mounting tolerances

Two active substitute parts meet these criteria and are available from alternative manufacturers with current production status.

Parameter Comparison

Engineering Selection Recommendations

37204000001 (Littelfuse Inc., TR5® 372 Series)

This substitute part is recommended as the primary equivalent for SR-5-400MA-AP replacement. The part maintains identical electrical specifications including 400 mA current rating, 250 V AC voltage rating, and slow-blow response time. Physical dimensions are within acceptable tolerance (0.335" Dia x 0.315" H versus 0.335" Dia x 0.319" H). The part holds ROHS3 compliance and carries active production status with 1974 units in stock. Approval agencies include CCC, cURus, SEMKO, and VDE. The TR5® 372 series is widely used in industrial and commercial applications requiring board mount fuse solutions.

MRT 400-AMMO (Bel Fuse Inc., MRT Series)

This substitute part provides an alternative equivalent with enhanced specifications suitable for applications requiring extended operating temperature range (-55°C ~ 125°C versus -40°C ~ 85°C) and higher breaking capacity (50 A versus 35 A). The part maintains identical electrical specifications for current rating, voltage rating, and response time. Physical dimensions show minor variation (0.329" Dia x 0.303" H) within acceptable mechanical fit tolerances. The part holds ROHS3 compliance, active production status with 855 units in stock, and carries AEC-Q200 automotive qualification in addition to CCC, CE, CSA, cURus, SEMKO, and VDE approvals. This part is suitable for applications requiring automotive-grade reliability or extended environmental operating conditions.

Frequently Asked Questions (FAQ)

Q: Can the 37204000001 be used as a direct replacement for SR-5-400MA-AP?

A: Yes. The 37204000001 maintains identical electrical specifications (400 mA, 250 V AC, slow-blow response) and compatible physical dimensions within standard PCB mounting tolerances. Both parts are through-hole radial, can-style board mount fuses with matching approval certifications.

Q: What is the difference between the two substitute parts?

A: Both substitutes meet the core electrical requirements. The 37204000001 provides a closer dimensional match to the original part. The MRT 400-AMMO offers extended operating temperature range (-55°C to 125°C versus -40°C to 85°C), higher breaking capacity (50 A versus 35 A), and includes AEC-Q200 automotive qualification. Selection depends on application-specific environmental and reliability requirements.

Q: Are there packaging differences between these parts?

A: Yes. The SR-5-400MA-AP is supplied in standard packaging. The 37204000001 is supplied in Cut Tape (CT) packaging. The MRT 400-AMMO is supplied in Tape & Box (TB) packaging. Packaging format may affect procurement, handling, and integration into automated assembly processes.

Q: Do all three parts have the same physical dimensions?

A: No. Minor dimensional variations exist: SR-5-400MA-AP is 0.335" Dia x 0.319" H; 37204000001 is 0.335" Dia x 0.315" H; MRT 400-AMMO is 0.329" Dia x 0.303" H. These variations are within acceptable mechanical fit tolerances for standard through-hole PCB mounting but should be verified against specific board layout constraints.

Q: Which substitute part has better availability?

A: The 37204000001 (Littelfuse) has higher current inventory at 1974 units in stock compared to MRT 400-AMMO at 855 units. Both parts carry active production status, ensuring ongoing availability for future procurement.

Q: Are all parts RoHS compliant?

A: Yes. The SR-5-400MA-AP is RoHS Compliant. Both substitute parts are ROHS3 Compliant, meeting current and future environmental regulatory requirements.

Q: What approval agencies certify these parts?

A: SR-5-400MA-AP carries CCC, cULus, KC-MARK, SEMKO, and VDE approvals. The 37204000001 carries CCC, cURus, SEMKO, and VDE approvals. The MRT 400-AMMO carries AEC-Q200, CCC, CE, CSA, cURus, SEMKO, and VDE approvals. The MRT 400-AMMO provides the broadest certification coverage including automotive qualification.

Q: Can the MRT 400-AMMO be used in applications with temperature extremes?

A: Yes. The MRT 400-AMMO operates across -55°C to 125°C, providing extended temperature capability compared to the original SR-5-400MA-AP (-40°C to 85°C) and the 37204000001 (-40°C to 85°C). This makes the MRT 400-AMMO suitable for automotive, industrial, and harsh environment applications.

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

A: Melting I²t values indicate the thermal energy required to melt the fuse element. The SR-5-400MA-AP has 0.771618, the 37204000001 has 1.408, and the MRT 400-AMMO has 1. These variations reflect different fuse element designs while maintaining the same 400 mA current rating and slow-blow response characteristic. All values are within acceptable ranges for fuse coordination in circuit protection applications.