Littelfuse 02301.25DRT3SW Glass Cartridge Fuse Equivalent & Substitute Parts

Part Overview

The Littelfuse 02301.25DRT3SW is a 1.25 A, 250 V AC glass cartridge fuse with slow-blow response characteristics, designed for through-hole mounting in axial configuration. This part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for ongoing production and field replacement applications.

Key Parameters

Parameter	Value
Manufacturer	Littelfuse Inc.
Current Rating	1.25 A
Voltage Rating - AC	250 V
Fuse Type	Cartridge, Glass
Response Time	Slow Blow
Mounting Type	Through Hole
Package / Case	Cartridge, Non-Standard (Axial)
Size / Dimension	0.177" Dia x 0.571" L (4.50mm x 14.50mm)
Melting I²t	9.8
DC Cold Resistance	0.145 Ohms
Operating Temperature	-55°C ~ 125°C
Series	230

Substitute Part Grouping Explanation

Substitution eligibility is determined by strict equivalence across the following parameters: current rating (1.25 A), AC voltage rating (250 V), fuse type (cartridge glass), response time (slow blow), physical dimensions (0.177" Dia x 0.571" L), melting I²t value (9.8), and mounting configuration (through-hole axial). All identified substitutes maintain these core electrical and mechanical specifications. Substitute parts are grouped into two categories: direct manufacturer equivalents with identical packaging and parametric equivalents with alternative packaging configurations, all rated for 250 V AC operation with 125 V DC capability.

Parameter Comparison

Part Number	Manufacturer	Current Rating (A)	Voltage AC (V)	Voltage DC (V)	Response Time	Melting I²t	DC Resistance (Ω)	Product Status	RoHS Status	Packaging
02301.25DRT3SW	Littelfuse Inc.	1.25	250	—	Slow Blow	9.8	0.145	Obsolete	RoHS Non-Compliant	Bulk
02301.25DRT3SP	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25DRT1P	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25DRT1SP	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25DRT2P	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25DRT2SP	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25DRT3P	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25MRT1EP	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel
02301.25MRT1SSP	Littelfuse Inc.	1.25	250	125	Slow Blow	9.8	0.146	Active	ROHS3 Compliant	Tape & Reel

Engineering Selection Recommendations

All listed substitute parts maintain electrical equivalence with the 02301.25DRT3SW across current rating, voltage specification, response time, and thermal characteristics. The primary distinction between the obsolete main part and active substitutes is product status and regulatory compliance. The main part carries RoHS non-compliant status, while all substitute options are ROHS3 compliant, meeting current environmental and regulatory requirements for new designs and production applications.

Packaging differences exist between the obsolete part (bulk) and substitute options (tape & reel format). Tape & reel packaging is standard for active production inventory and automated assembly processes. DC voltage rating enhancement (125 V DC) in substitute parts provides expanded application flexibility without compromising AC circuit protection performance.

Selection among substitute parts should be based on internal packaging and supply chain requirements, as all alternatives are electrically and mechanically interchangeable for the specified 1.25 A, 250 V AC slow-blow cartridge fuse application.

Frequently Asked Questions (FAQ)

Q: Can 02301.25DRT3SP directly replace 02301.25DRT3SW in existing designs?

A: Yes. Both parts share identical electrical ratings (1.25 A, 250 V AC), response time (slow blow), physical dimensions (0.177" Dia x 0.571" L), and melting I²t value (9.8). The primary difference is packaging format (bulk versus tape & reel) and regulatory compliance status. Electrical performance and circuit protection characteristics are equivalent.

Q: What is the significance of the 125 V DC rating in substitute parts?

A: The substitute parts are rated for both 250 V AC and 125 V DC operation, whereas the obsolete part specifies only 250 V AC. This expanded DC rating does not affect AC circuit protection performance and provides additional application flexibility for designs requiring DC voltage capability.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All identified substitute parts carry ROHS3 compliance status. The obsolete main part (02301.25DRT3SW) is RoHS non-compliant. For new production and designs subject to environmental regulations, substitute parts meet current compliance requirements.

Q: Does packaging format affect electrical performance?

A: No. Tape & reel packaging is a supply and assembly format consideration only. Electrical characteristics, protection performance, and circuit behavior remain identical between bulk and tape & reel configurations of the same fuse specification.

Q: Are there approval agency differences between the main part and substitutes?

A: The obsolete main part carries CSA, METI, and UL approvals. Substitute parts carry CE, CSA, PSE, and UL approvals, providing broader international regulatory recognition suitable for global applications.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message