Equivalent & Substitute Parts for 3SB 5-R Glass Cartridge Fuse

Part Overview

The 3SB 5-R is a 5 A, 250 V AC/DC slow-blow glass cartridge fuse manufactured by Bel Fuse Inc. This component is designed for circuit protection in applications requiring a 3AB/3AG form factor with a 1/4" x 1-1/4" package. The part maintains Active product status with 900 units in current inventory. Substitute parts are necessary to address supply chain flexibility, alternative sourcing options, and compatibility with systems that accept equivalent electrical and mechanical specifications.

Key Parameters

Parameter	Value
Current Rating	5 A
Voltage Rating (AC)	250 V
Fuse Type	Cartridge, Glass
Response Time	Slow Blow
Package / Case	3AB, 3AG, 1/4" x 1-1/4"
Breaking Capacity @ Rated Voltage	200 A
Operating Temperature Range	-55°C ~ 125°C
Mounting Type	Requires Holder
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution of the 3SB 5-R is determined by strict equivalence across the following parameters:

Current Rating: 5 A (exact match required)
Voltage Rating (AC): 250 V (exact match required)
Fuse Type: Cartridge, Glass (exact match required)
Response Time: Slow Blow (exact match required)
Package / Case: 3AB, 3AG, 1/4" x 1-1/4" (exact match required)
Breaking Capacity @ Rated Voltage: 200 A (exact match required)
Operating Temperature Range: -55°C ~ 125°C (exact match required)
Mounting Type: Requires Holder (exact match required)

All substitute parts listed below meet these criteria. Variations in secondary parameters such as Melting I²t, DC Cold Resistance, and specific approval agency certifications do not disqualify substitution when primary electrical and mechanical specifications are identical.

Parameter Comparison

Parameter	3SB 5-R (Bel Fuse)	0313005.HXP (Littelfuse)	0313005.MXP (Littelfuse)	0313005.HXIDP (Littelfuse)	0313005.VXIDP (Littelfuse)
Current Rating (Amps)	5 A	5 A	5 A	5 A	5 A
Voltage Rating - AC	250 V	250 V	250 V	250 V	250 V
Fuse Type	Cartridge, Glass	Cartridge, Glass	Cartridge, Glass	Cartridge, Glass	Cartridge, Glass
Response Time	Slow Blow	Slow Blow	Slow Blow	Slow Blow	Slow Blow
Package / Case	3AB, 3AG, 1/4" x 1-1/4"	3AB, 3AG, 1/4" x 1-1/4"	3AB, 3AG, 1/4" x 1-1/4"	3AB, 3AG, 1/4" x 1-1/4"	3AB, 3AG, 1/4" x 1-1/4"
Breaking Capacity @ Rated Voltage	200 A	200 A	200 A	200 A	200 A
Operating Temperature	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C	-55°C ~ 125°C
Mounting Type	Requires Holder	Requires Holder	Requires Holder	Requires Holder	Requires Holder
Size / Dimension	0.250" Dia x 1.252" L (6.35mm x 31.80mm)	0.250" Dia x 1.250" L (6.35mm x 31.75mm)	0.250" Dia x 1.250" L (6.35mm x 31.75mm)	0.250" Dia x 1.250" L (6.35mm x 31.75mm)	0.250" Dia x 1.250" L (6.35mm x 31.75mm)
DC Cold Resistance	0.03 Ohms	0.0214 Ohms	0.0214 Ohms	0.0214 Ohms	0.0214 Ohms
Melting I²t	349	140	276	140	140
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	CE, CSA, cULus, PSE	CE, CSA, K-MARK, PSE, UL	CE, CSA, K-MARK, PSE, UL	CE, CSA, KC, PSE, UL	CE, CSA, KC, PSE, UL

Engineering Selection Recommendations

All four Littelfuse substitute parts (0313005.HXP, 0313005.MXP, 0313005.HXIDP, 0313005.VXIDP) are functionally equivalent to the 3SB 5-R and maintain Active product status. Selection among these alternatives is based on:

Approval Agency Coverage: The 0313005.HXP and 0313005.MXP variants carry CSA, K-MARK, and UL certifications. The 0313005.HXIDP and 0313005.VXIDP variants carry KC and UL certifications. Choose based on regional compliance requirements.

Inventory Availability: 0313005.HXP (5083 units), 0313005.MXP (2198 units), 0313005.HXIDP (729 units), and 0313005.VXIDP (755 units) are all in stock. Selection may be driven by supply chain lead time and quantity requirements.

All substitute parts maintain ROHS3 compliance and REACH Unaffected status, consistent with the original 3SB 5-R specification.

Frequently Asked Questions (FAQ)

Q: Can 0313005.HXP, 0313005.MXP, 0313005.HXIDP, and 0313005.VXIDP be used interchangeably with the 3SB 5-R?

A: Yes. All four Littelfuse parts meet the core electrical and mechanical specifications: 5 A current rating, 250 V AC voltage rating, slow-blow response, 3AB/3AG package form factor, and 200 A breaking capacity. They are direct substitutes for the 3SB 5-R in applications requiring these specifications.

Q: What is the difference between the Littelfuse substitute options?

A: The primary differences are approval agency certifications and Melting I²t values. 0313005.HXP and 0313005.VXIDP have Melting I²t of 140, while 0313005.MXP has 140 and 0313005.HXIDP has 140. The 0313005.MXP variant has a Melting I²t of 276. Approval agencies vary: 0313005.HXP and 0313005.MXP include K-MARK certification, while 0313005.HXIDP and 0313005.VXIDP include KC certification. Select based on regional regulatory requirements.

Q: Are there dimensional differences between the 3SB 5-R and the Littelfuse substitutes?

A: The 3SB 5-R measures 0.250" Dia x 1.252" L (6.35mm x 31.80mm), while all Littelfuse substitutes measure 0.250" Dia x 1.250" L (6.35mm x 31.75mm). This 0.002" (0.05mm) difference in length is within standard mechanical tolerance for 3AB/3AG cartridge fuses and does not affect holder compatibility or electrical performance.

Q: Do all substitute parts require the same holder as the 3SB 5-R?

A: Yes. All substitute parts are specified for 3AB and 3AG holders, identical to the 3SB 5-R. No holder modification or replacement is required when substituting.

Q: What certifications should I verify for my application?

A: Verify that the selected substitute part carries the approval agencies required by your regional standards and application. The 3SB 5-R carries CE, CSA, cULus, and PSE certifications. Littelfuse substitutes carry overlapping certifications with regional variations (K-MARK or KC). Confirm alignment with your compliance requirements before selection.

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