Littelfuse 0452002.MRSN Surface Mount Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 0452002.MRSN is a 2 A, 125 V AC/DC surface mount board mount fuse in the NANO²® 452 series. This slow blow fuse is designed for circuit protection in applications requiring reliable overcurrent protection with a 50 A breaking capacity. The part is actively manufactured and widely stocked, with 1851 pieces available in original condition. Equivalent and substitute parts are identified to support procurement flexibility, alternative sourcing, packaging options, and inventory management across related NANO²® series fuses that maintain identical electrical and mechanical specifications.

Key Parameters

Parameter	Value
Current Rating	2 A
Voltage Rating (AC)	125 V
Voltage Rating (DC)	125 V
Response Time	Slow Blow
Mounting Type	Surface Mount
Package / Case	2-SMD, Square End Block
Physical Dimensions	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)
Breaking Capacity @ Rated Voltage	50 A
Operating Temperature Range	-55°C to 125°C
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the 0452002.MRSN is determined by strict equivalence across the following critical parameters: current rating (2 A), AC voltage rating (125 V), DC voltage rating (125 V), response time (Slow Blow), mounting type (Surface Mount), package configuration (2-SMD, Square End Block), physical dimensions (0.240" L x 0.106" W x 0.106" H), breaking capacity (50 A), and operating temperature range (-55°C to 125°C).

Substitute parts are grouped into two categories:

Category 1: Same Series, Different Packaging Parts 0452002.MRL and 0452002.NRL maintain identical electrical characteristics and physical dimensions as the main part but differ in packaging format (Cut Tape & Digi-Reel® or alternative Tape & Reel configuration). These are direct substitutes with no functional differences.

Category 2: Alternative Series, Identical Electrical Specifications Parts 0449002.MR and 0454002.MR represent alternative NANO²® series fuses (449 and 454 respectively) that meet all core electrical and mechanical requirements. Minor variations in melting I²t values and DC cold resistance are within acceptable tolerance for functional equivalence. Approval agency certifications differ slightly but all parts maintain active product status and ROHS3 compliance.

Parameter Comparison

Parameter	0452002.MRSN	0449002.MR	0452002.MRL	0452002.NRL	0454002.MR
Manufacturer	Littelfuse	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.	Littelfuse Inc.
Series	NANO²® 452	NANO²® 449	NANO²® 452	NANO²® 452	NANO²® 454
Current Rating (Amps)	2 A	2 A	2 A	2 A	2 A
Voltage Rating - AC	125 V	125 V	125 V	125 V	125 V
Voltage Rating - DC	125 V	125 V	125 V	125 V	125 V
Response Time	Slow Blow	Slow Blow	Slow Blow	Slow Blow	Slow Blow
Mounting Type	Surface Mount	Surface Mount	Surface Mount	Surface Mount	Surface Mount
Package / Case	2-SMD, Square End Block	2-SMD, Square End Block	2-SMD, Square End Block	2-SMD, Square End Block	2-SMD, Square End Block
Size / Dimension	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)	0.240" L x 0.106" W x 0.106" H (6.10mm x 2.69mm x 2.69mm)
Breaking Capacity @ Rated Voltage	50 A	50 A	50 A	50 A	50 A
Melting I²t	8.2	6.76	8.2	8.2	8.2
DC Cold Resistance (Ohms)	0.0625	0.0708	0.0625	0.0625	0.0625
Operating Temperature	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)	1 (Unlimited)
Packaging	Tape & Reel (TR)	Tape & Reel (TR)	Cut Tape (CT) & Digi-Reel®	Tape & Reel (TR)	Cut Tape (CT) & Digi-Reel®
Product Status	Active	Active	Active	Active	Active
Inventory (Pcs)	1851	1900	141490	12715	13200

Engineering Selection Recommendations

All substitute parts listed maintain active product status and full ROHS3 compliance, ensuring long-term availability and environmental regulatory adherence. Selection between the main part 0452002.MRSN and its substitutes should be based on packaging requirements and inventory availability.

For applications requiring Tape & Reel packaging, both 0452002.MRSN and 0452002.NRL are suitable. The 0452002.NRL offers significantly higher inventory (12,715 pieces) compared to the main part (1,851 pieces), supporting high-volume procurement needs.

For applications compatible with Cut Tape & Digi-Reel® packaging, parts 0452002.MRL and 0454002.MR provide alternatives. The 0452002.MRL offers the largest available inventory (141,490 pieces) and maintains identical electrical characteristics to the main part, including melting I²t of 8.2 and DC cold resistance of 0.0625 Ohms.

The 0449002.MR represents an alternative series option with slightly different thermal characteristics (melting I²t of 6.76 and DC cold resistance of 0.0708 Ohms) but maintains all critical electrical and mechanical specifications. This part is available in Tape & Reel packaging with 1,900 pieces in stock.

All parts carry CSA, PSE, and UL/UR certifications appropriate to their respective series designations, supporting global regulatory compliance requirements.

Frequently Asked Questions (FAQ)

Q: Can 0452002.MRL be used as a direct replacement for 0452002.MRSN?

A: Yes. Both parts are from the NANO²® 452 series with identical current rating (2 A), voltage ratings (125 V AC/DC), response time (Slow Blow), physical dimensions (0.240" L x 0.106" W x 0.106" H), melting I²t (8.2), and DC cold resistance (0.0625 Ohms). The only difference is packaging format: 0452002.MRSN uses Tape & Reel (TR) while 0452002.MRL uses Cut Tape (CT) & Digi-Reel®. Selection depends on your assembly equipment compatibility.

Q: What is the difference between 0452002.MRSN and 0449002.MR?

A: Both parts share identical current rating (2 A), voltage ratings (125 V AC/DC), response time (Slow Blow), mounting type (Surface Mount), package configuration (2-SMD, Square End Block), and physical dimensions. The 0449002.MR belongs to the NANO²® 449 series and has a melting I²t of 6.76 compared to 8.2 for the 0452002.MRSN, and DC cold resistance of 0.0708 Ohms versus 0.0625 Ohms. These differences are within acceptable tolerance for functional equivalence in circuit protection applications.

Q: Which substitute part has the best inventory availability?

A: The 0452002.MRL offers the highest inventory with 141,490 pieces available. This part is suitable for high-volume production runs and provides the same electrical specifications as the main part 0452002.MRSN, with the only difference being Cut Tape & Digi-Reel® packaging instead of Tape & Reel.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (0449002.MR, 0452002.MRL, 0452002.NRL, and 0454002.MR) are ROHS3 compliant with Moisture Sensitivity Level 1 (Unlimited), matching the environmental and regulatory compliance of the main part 0452002.MRSN.

Q: Can I use 0454002.MR as a substitute?

A: Yes. The 0454002.MR from the NANO²® 454 series meets all critical electrical and mechanical requirements: 2 A current rating, 125 V AC/DC voltage ratings, Slow Blow response, 50 A breaking capacity, and identical physical dimensions. It is available in Cut Tape & Digi-Reel® packaging with 13,200 pieces in stock.

Q: What certifications do these fuses carry?

A: The main part 0452002.MRSN carries CSA, METI, and UR certifications. Substitute parts carry varying combinations of CSA, PSE, UL, and UR certifications. All parts maintain active product status and support global regulatory compliance requirements.

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