Bel Fuse Inc. 5MT 2.5 Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Bel Fuse Inc. 5MT 2.5 is a 2.5 A 250 V AC/DC glass cartridge fuse in 5mm x 20mm form factor with medium blow response time. This component is classified as obsolete, requiring identification of active equivalent and substitute parts for ongoing system support and new designs. Substitute parts must maintain electrical compatibility across current rating, voltage rating, package dimensions, and mechanical mounting requirements while meeting applicable regulatory certifications.

Key Parameters

Parameter	Value
Current Rating	2.5 A
Voltage Rating (AC)	250 V
Package / Case	5mm x 20mm
Fuse Type	Cartridge, Glass
Mounting Type	Requires Holder
Response Time	Medium Blow
Breaking Capacity @ Rated Voltage	100 A
Operating Temperature Range	-55°C ~ 125°C

Substitute Part Grouping Explanation

Substitute parts are grouped based on strict electrical and mechanical compatibility criteria. All substitute parts must match the following core parameters from the main part:

Current Rating: 2.5 A (exact match required)
Voltage Rating (AC): 250 V (exact match required)
Package / Case: 5mm x 20mm (exact match required)
Fuse Type: Cartridge, Glass (exact match required)
Mounting Type: Requires Holder (exact match required)

Response time classification (Medium Blow vs. Slow Blow) and breaking capacity are secondary parameters that may vary between substitutes depending on application requirements. Substitutes are organized by manufacturer and product status to facilitate selection based on availability and regulatory compliance.

Parameter Comparison

Part Number	Manufacturer	Current Rating (A)	Voltage Rating (V AC)	Package	Response Time	Breaking Capacity (A)	Melting I²t	DC Cold Resistance (Ω)	Product Status	RoHS Status
5MT 2.5	Bel Fuse Inc.	2.5	250	5mm x 20mm	Medium Blow	100	35	0.039	Obsolete	RoHS non-compliant
021802.5HXP	Littelfuse	2.5	250	5mm x 20mm	Slow Blow	35	23.25	0.0219	Active	ROHS3 Compliant
021802.5TXP	Littelfuse Inc.	2.5	250	5mm x 20mm	Slow Blow	35	23.25	0.0219	Active	ROHS3 Compliant
023202.5MXP	Littelfuse Inc.	2.5	250	5mm x 20mm	Medium Blow	100	13.875	0.0291	Active	ROHS3 Compliant
BK1/GMC-2.5-R	Eaton - Electronics Division	2.5	250	5mm x 20mm	Medium Blow	100	13	0.035	Active	ROHS3 Compliant
BK1/GMD-2.5-R	Eaton - Electronics Division	2.5	250	5mm x 20mm	Slow Blow	100	94	0.0905	Active	ROHS3 Compliant
GDC-2.5A	Eaton - Electronics Division	2.5	250	5mm x 20mm	Slow Blow	35	59.4	0.0255	Active	Not specified

Engineering Selection Recommendations

All listed substitute parts maintain electrical and mechanical compatibility with the 5MT 2.5 across the core parameters of current rating, voltage rating, package dimensions, and mounting type. Selection should be based on the following criteria:

Medium Blow Response Time Match: The 023202.5MXP (Littelfuse) and BK1/GMC-2.5-R (Eaton) provide medium blow response time matching the original 5MT 2.5 specification. Both are active products with ROHS3 compliance.

Slow Blow Response Time Alternatives: The 021802.5HXP, 021802.5TXP (Littelfuse), BK1/GMD-2.5-R, and GDC-2.5A (Eaton) provide slow blow response time. These are suitable for applications requiring extended thermal protection characteristics.

Regulatory Compliance: All substitute parts except GDC-2.5A carry explicit ROHS3 compliance certification. The original 5MT 2.5 is RoHS non-compliant. For applications requiring RoHS compliance, select from the ROHS3-compliant alternatives.

Breaking Capacity Considerations: The 023202.5MXP, BK1/GMC-2.5-R, and BK1/GMD-2.5-R maintain 100 A breaking capacity matching the original part. The 021802.5HXP, 021802.5TXP, and GDC-2.5A provide 35 A breaking capacity.

Availability: Littelfuse 021802.5HXP shows highest inventory (21,272 pcs). All substitute parts are in active production status.

Frequently Asked Questions (FAQ)

Q: Can I use a slow blow fuse as a substitute for the medium blow 5MT 2.5?

A: Slow blow and medium blow fuses have different thermal response characteristics determined by their melting I²t values. Substitution between response time classifications requires circuit analysis to ensure the application can tolerate the different trip characteristics. Both response times are electrically compatible at the 2.5 A, 250 V rating and 5mm x 20mm package.

Q: What is the significance of breaking capacity differences between substitutes?

A: Breaking capacity indicates the maximum fault current the fuse can safely interrupt. The 5MT 2.5 and several substitutes (023202.5MXP, BK1/GMC-2.5-R, BK1/GMD-2.5-R) are rated at 100 A breaking capacity. Others (021802.5HXP, 021802.5TXP, GDC-2.5A) are rated at 35 A. Selection should match or exceed the system's maximum available fault current.

Q: Are all substitute parts physically interchangeable in the same fuse holder?

A: Yes. All substitute parts maintain the 5mm x 20mm package dimension and require the same holder type. Physical installation is identical across all listed parts.

Q: Which substitute should I select for new designs?

A: For new designs, prioritize active products with ROHS3 compliance. The 023202.5MXP (medium blow) or BK1/GMC-2.5-R (medium blow) match the original response time. The 021802.5HXP (slow blow) offers highest availability. Verify breaking capacity requirements against your system's maximum available fault current.

Q: What certifications do the substitute parts carry?

A: Littelfuse 021802.5HXP and 021802.5TXP carry CCC, CE, CSA, K-MARK, PSE, SEMKO, UL, VDE certifications. Littelfuse 023202.5MXP carries CE, KC, PSE certifications. Eaton BK1/GMC-2.5-R carries CSA, KC, MITI, UL certifications. Eaton BK1/GMD-2.5-R carries CSA, PSE/JET, UL certifications. Eaton GDC-2.5A carries cURus, IMQ, MITI/JET certifications. Verify certification requirements for your specific application.

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