SSQ 2.5/5K Surface Mount Board Mount Fuse Equivalent & Substitute Parts

Part Overview

The SSQ 2.5/5K is a 2.5 A, 125 V AC/DC surface mount board mount fuse manufactured by Bel Fuse Inc. in a 2-SMD, Square End Block package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The fuse provides fast-blow response with a breaking capacity of 50 A AC and 300 A DC, suitable for circuit protection in compact surface mount applications.

Substiute Parts

SSQ 2.5/5K

Bel Fuse Inc.In Stock: 993SSQ 2.5/5K Datasheet

Current PartRFQ

0679L2500-05

Bel Fuse Inc.In Stock: 302620679L2500-05 Datasheet

DirectRFQ

047602.5MR

Littelfuse Inc.In Stock: 16307047602.5MR Datasheet

DirectRFQ

047602.5MRSN

Littelfuse Inc.In Stock: 853047602.5MRSN Datasheet

DirectRFQ

045102.5MRSN

Littelfuse Inc.In Stock: 2541045102.5MRSN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SSQ 2.5/5K is determined by the following critical parameters:

• Current Rating: 2.5 A (exact match required)
• Voltage Rating (AC): 125 V minimum
• Voltage Rating (DC): 125 V minimum
• Response Time: Fast Blow
• Mounting Type: Surface Mount
• Package / Case: 2-SMD, Square End Block
• Operating Temperature Range: -55°C to 125°C
• RoHS Compliance: ROHS3 Compliant

Substitute parts are grouped into two categories:

Direct Substitutes (full parameter compatibility): Parts that match all critical electrical and mechanical parameters of the SSQ 2.5/5K.

Similar Substitutes (compatible with design constraints): Parts that maintain the same current rating, response time, and mounting type but may have different voltage ratings or breaking capacities. These are suitable when the application permits higher voltage ratings or different breaking capacities.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: 0679L2500-05 (Bel Fuse Inc.)

The 0679L2500-05 is the recommended direct substitute for the SSQ 2.5/5K. Both parts are manufactured by Bel Fuse Inc. and share identical electrical ratings (2.5 A, 125 V AC/DC), response time (Fast Blow), and breaking capacity (50 A AC, 300 A DC). The 0679L2500-05 is active in production with substantial inventory availability (30,231 pcs). Both parts are ROHS3 compliant and operate across the same temperature range (-55°C to 125°C). The primary difference is packaging format: the SSQ 2.5/5K is supplied in bulk, while the 0679L2500-05 is supplied in Tape & Reel format, which is standard for automated assembly processes.

Secondary Substitutes: 047602.5MR and 047602.5MRSN (Littelfuse Inc., NANO²® 476 Series)

The 047602.5MR and 047602.5MRSN are functionally compatible substitutes manufactured by Littelfuse Inc. Both maintain the 2.5 A current rating and Fast Blow response time. The key difference is elevated AC voltage rating (250 V AC versus 125 V AC), which provides enhanced circuit protection capability. Both parts have higher breaking capacity (100 A AC versus 50 A AC). These parts are suitable for applications where the higher voltage rating does not conflict with circuit design constraints. Both are ROHS3 compliant and operate within the same temperature range. The 047602.5MRSN has limited inventory (827 pcs), while the 047602.5MR has higher availability (16,203 pcs).

Tertiary Substitute: 045102.5MRSN (Littelfuse Inc., NANO²® 451 Series)

The 045102.5MRSN is a similar substitute with matching 2.5 A current rating, Fast Blow response time, and 125 V AC voltage rating. DC voltage rating is not specified in the provided data. This part is suitable for applications operating at 125 V AC with equivalent breaking capacity (50 A AC). It is active in production with moderate inventory (2,530 pcs) and is ROHS3 compliant.

Frequently Asked Questions (FAQ)

Q: Can the 0679L2500-05 be used as a direct replacement for the SSQ 2.5/5K?

A: Yes. The 0679L2500-05 is a direct electrical and mechanical equivalent. Both parts have identical current ratings (2.5 A), voltage ratings (125 V AC/DC), response time (Fast Blow), and breaking capacity (50 A AC, 300 A DC). The primary difference is packaging: the 0679L2500-05 is supplied in Tape & Reel format, which is standard for automated PCB assembly.

Q: What is the difference between the Littelfuse 047602.5MR and 047602.5MRSN?

A: Both parts are electrically identical with 2.5 A current rating, 250 V AC / 125 V DC voltage ratings, and 100 A AC breaking capacity. The difference is in product designation and inventory availability. The 047602.5MR has higher stock (16,203 pcs) compared to the 047602.5MRSN (827 pcs).

Q: Can I use a 250 V AC rated fuse (047602.5MR or 047602.5MRSN) in a circuit designed for 125 V AC?

A: Yes. A fuse with a higher voltage rating can be used in a lower voltage application. The 250 V AC rating provides additional safety margin. However, verify that all other parameters (current rating, response time, breaking capacity, and package dimensions) are compatible with your circuit design.

Q: What is the significance of the Tape & Reel (TR) packaging?

A: Tape & Reel packaging is the standard format for automated surface mount assembly. It allows for high-speed pick-and-place machine processing. If your manufacturing process uses automated assembly, Tape & Reel packaged parts (0679L2500-05, 047602.5MR, 047602.5MRSN, 045102.5MRSN) are required. Bulk packaging is used for manual assembly or low-volume applications.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts (0679L2500-05, 047602.5MR, 047602.5MRSN, and 045102.5MRSN) are ROHS3 compliant, matching the compliance status of the SSQ 2.5/5K.

Q: What is the operating temperature range for these fuses?

A: All parts listed operate across the temperature range of -55°C to 125°C, which is suitable for industrial and commercial applications.

Q: Why is the SSQ 2.5/5K classified as obsolete?

A: The SSQ 2.5/5K is no longer in active production. Active alternatives such as the 0679L2500-05 (same manufacturer) and the Littelfuse NANO²® series (047602.5MR, 047602.5MRSN) provide equivalent or enhanced functionality and are recommended for new designs and ongoing procurement.