SR-5-2.5A-AP Equivalent & Substitute Parts Reference

Part Overview

The SR-5-2.5A-AP is a 2.5 A, 250 V AC/DC board mount fuse manufactured by Eaton - Electronics Division. This radial, can-style through-hole fuse features slow-blow response characteristics and is designed for circuit protection in industrial and commercial applications. The part is currently active in production with 1299 pieces in stock. Equivalent and substitute parts are identified based on matching electrical ratings, mechanical compatibility, and functional performance within the allowed parameter specifications for board mount fuse applications.

Substiute Parts

SR-5-2.5A-AP

Eaton - Electronics DivisionIn Stock: 1403SR-5-2.5A-AP Datasheet

Current PartRFQ

37012500000

Littelfuse Inc.In Stock: 145337012500000 Datasheet

SimilarRFQ

37212500001

Littelfuse Inc.In Stock: 1637337212500001 Datasheet

SimilarRFQ

MRT 2.5-AMMO

Bel Fuse Inc.In Stock: 3830MRT 2.5-AMMO Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SR-5-2.5A-AP are qualified based on the following mandatory matching criteria:

Electrical Parameters (Must Match):

• Current Rating: 2.5 A
• Voltage Rating (AC): 250 V
• Response Time: Slow Blow

Mechanical Parameters (Must Match):

• Mounting Type: Through Hole
• Fuse Type: Board Mount (Cartridge Style Excluded)
• Package / Case: Radial, Can, Vertical

Performance Parameters (Must Meet or Exceed):

• Breaking Capacity @ Rated Voltage: ≥ 35 A
• Operating Temperature Range: Must encompass -40°C ~ 85°C minimum

Compliance Parameters:

• RoHS Status: Compliant
• Approval Agencies: Must include CCC, PSE, SEMKO, VDE at minimum

The following parts meet all substitution criteria:

1. 37212500001 (Littelfuse Inc., TR5® 372 Series) – Exact electrical and mechanical match with slow-blow response
2. MRT 2.5-AMMO (Bel Fuse Inc., MRT Series) – Exact electrical and mechanical match with slow-blow response and extended temperature range

The part 37012500000 (Littelfuse Inc., TR5® 370 Series) is listed as a similar part but features Fast Blow response time, which differs from the slow-blow characteristic of the main part and is not recommended for direct substitution without circuit design verification.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Replacement):

37212500001 (Littelfuse TR5® 372) is the recommended primary substitute. This part matches all critical electrical and mechanical parameters of the SR-5-2.5A-AP, including 2.5 A current rating, 250 V AC voltage rating, and slow-blow response time. Both parts share identical operating temperature range (-40°C ~ 85°C) and equivalent breaking capacity (35 A). The part holds ROHS3 compliance and carries CCC, cURus, PSE, SEMKO, and VDE approvals. Inventory availability is significantly higher (16275 pieces), supporting supply chain continuity.

MRT 2.5-AMMO (Bel Fuse MRT Series) is an alternative primary substitute with identical electrical ratings and slow-blow response. This part offers extended operating temperature range (-55°C ~ 125°C) and higher breaking capacity (50 A), providing additional performance margin. The MRT series carries AEC-Q200 qualification, indicating automotive-grade reliability. Physical dimensions are slightly smaller (0.329" Dia x 0.303" H versus 0.335" Dia x 0.319" H), requiring verification of PCB footprint compatibility. ROHS3 compliance and comprehensive approval agency certifications (CCC, CE, CSA, cURus, PSE, SEMKO, VDE) are confirmed.

Not Recommended for Direct Substitution:

37012500000 (Littelfuse TR5® 370) features Fast Blow response time, which differs fundamentally from the slow-blow characteristic of the SR-5-2.5A-AP. This response time difference alters circuit protection behavior and inrush current tolerance, making this part unsuitable for direct substitution without circuit design modification and validation.

Frequently Asked Questions (FAQ)

Q: Can the 37012500000 (Fast Blow) be used as a substitute for the SR-5-2.5A-AP (Slow Blow)?

A: No. Although both parts share identical current rating (2.5 A), voltage rating (250 V), and mechanical form factor, the response time difference is a fundamental functional parameter. Fast Blow fuses interrupt circuits more rapidly than slow-blow fuses, affecting inrush current tolerance and circuit protection behavior. Substitution requires circuit design verification and is not recommended for direct replacement.

Q: What is the significance of the Melting I²t parameter in fuse substitution?

A: Melting I²t defines the thermal energy required to melt the fuse element and is directly related to response time and current-carrying capacity. The SR-5-2.5A-AP has a Melting I²t of 45, while the 37212500001 has 35 and the MRT 2.5-AMMO has 43. These variations reflect different fuse element designs but remain within acceptable ranges for slow-blow applications. The 37012500000 (Fast Blow) has a significantly lower Melting I²t of 1.8, confirming its fundamentally different response characteristic.

Q: Are there physical dimension differences between the recommended substitutes?

A: Yes. The SR-5-2.5A-AP measures 0.335" Dia x 0.319" H (8.50mm x 8.10mm). The 37212500001 measures 0.335" Dia x 0.315" H (8.50mm x 8.00mm), representing a negligible height difference of 0.004" (0.10mm). The MRT 2.5-AMMO measures 0.329" Dia x 0.303" H (8.35mm x 7.70mm), with slightly smaller diameter and height. These dimensional variations are within typical manufacturing tolerances for radial, can-style fuses. PCB footprint compatibility should be verified for the MRT 2.5-AMMO due to its smaller diameter.

Q: What is the difference between RoHS and ROHS3 compliance?

A: RoHS (Restriction of Hazardous Substances) compliance indicates conformance to the original directive restricting lead, cadmium, mercury, and other hazardous substances. ROHS3 represents compliance with the updated directive (2011/65/EU as amended by 2015/863/EU), which includes additional restricted substances such as phthalates. The SR-5-2.5A-AP is RoHS Compliant, while both recommended substitutes (37212500001 and MRT 2.5-AMMO) are ROHS3 Compliant, indicating higher environmental compliance standards.

Q: Does the extended operating temperature range of the MRT 2.5-AMMO (-55°C ~ 125°C) provide any advantage?

A: The extended temperature range of the MRT 2.5-AMMO provides operational capability in more extreme thermal environments compared to the SR-5-2.5A-AP and 37212500001, both rated -40°C ~ 85°C. This advantage is relevant only if the application requires operation below -40°C or above 85°C. For applications within the standard -40°C ~ 85°C range, the extended range provides no functional benefit but does not introduce compatibility issues.

Q: What is the significance of AEC-Q200 qualification on the MRT 2.5-AMMO?

A: AEC-Q200 is an automotive electronics qualification standard that specifies reliability and quality requirements for passive components used in automotive applications. The MRT 2.5-AMMO's AEC-Q200 qualification indicates it has undergone rigorous testing for temperature cycling, vibration, and long-term reliability. This qualification is relevant for automotive or high-reliability applications but is not required for general industrial circuit protection applications.

Q: Can packaging format (Cut Tape vs. Tape & Box) affect substitution decisions?

A: Packaging format affects handling, storage, and assembly processes but does not impact electrical or mechanical compatibility. The SR-5-2.5A-AP and 37212500001 are supplied in Cut Tape (CT) format, while the MRT 2.5-AMMO is supplied in Tape & Box (TB) format. Selection between these formats depends on assembly line requirements and inventory management practices rather than functional performance.