SSQ 1.6/5K Equivalent & Substitute Parts

Part Overview

The SSQ 1.6/5K is a 1.6 A surface mount board mount fuse manufactured by Bel Fuse Inc., rated for 125 V AC and 125 V DC operation with fast blow response characteristics. This component is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, maintenance, and production continuity. Substitute parts must maintain electrical compatibility while meeting the same mechanical and thermal specifications for direct board-level replacement.

Substiute Parts

SSQ 1.6/5K

Bel Fuse Inc.In Stock: 810SSQ 1.6/5K Datasheet

Current PartRFQ

047601.6MR

Littelfuse Inc.In Stock: 1696047601.6MR Datasheet

DirectRFQ

047601.6MRSN

Littelfuse Inc.In Stock: 1009047601.6MRSN Datasheet

DirectRFQ

045101.6MRSN

Littelfuse Inc.In Stock: 1050045101.6MRSN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SSQ 1.6/5K are classified into two categories based on electrical parameter alignment:

Direct Substitutes (047601.6MR, 047601.6MRSN): These Littelfuse NANO²®476 series fuses maintain the 1.6 A current rating, 125 V DC voltage rating, fast blow response, and identical mechanical package (2-SMD, Square End Block). The AC voltage rating is elevated to 250 V, which provides enhanced overvoltage margin while remaining fully compatible with 125 V AC circuit applications. Both parts share identical breaking capacity at rated voltage (100A AC, 300A DC) and operating temperature range (-55°C ~ 125°C).

Similar Substitute (045101.6MRSN): The Littelfuse NANO²®451 series fuse maintains the 1.6 A current rating, 125 V AC voltage rating, fast blow response, and identical mechanical package. This part does not specify a DC voltage rating and has a reduced breaking capacity (50A AC only), making it suitable for AC-dominant applications where DC performance is not critical.

Substitution eligibility is determined by: current rating match (1.6 A), voltage rating compatibility (minimum 125 V AC and 125 V DC for direct substitutes), response time match (fast blow), mechanical package compatibility (2-SMD, Square End Block), and operating temperature range alignment (-55°C ~ 125°C).

Parameter Comparison

Engineering Selection Recommendations

For applications requiring both AC and DC operation: Select 047601.6MR or 047601.6MRSN. Both parts are active products from Littelfuse with enhanced AC voltage rating (250 V) and maintained DC voltage rating (125 V), providing superior margin over the obsolete SSQ 1.6/5K. These parts carry cURus approval and are functionally equivalent for dual-voltage circuits.

For AC-only applications: The 045101.6MRSN is suitable where DC performance is not required. This part maintains the original 125 V AC rating and carries CSA and UR approvals. However, the absence of specified DC voltage rating and reduced breaking capacity (50A AC) restricts its use to AC-dominant circuits.

Packaging and inventory considerations: All substitute parts are available in Tape & Reel (TR) packaging, supporting automated assembly processes. Current inventory levels are substantial (047601.6MR: 1653 pcs, 047601.6MRSN: 933 pcs, 045101.6MRSN: 1021 pcs), ensuring supply continuity.

Frequently Asked Questions (FAQ)

Q: Can 047601.6MR and 047601.6MRSN be used interchangeably? A: Yes. Both parts are identical Littelfuse NANO²®476 series fuses with the same electrical ratings, mechanical package, and performance characteristics. The difference is packaging format (047601.6MR is standard Tape & Reel, 047601.6MRSN includes additional specification notation). Selection depends on procurement and assembly requirements.

Q: Why does 047601.6MR have a higher AC voltage rating (250 V) than the original SSQ 1.6/5K (125 V)? A: The elevated AC voltage rating provides enhanced overvoltage protection margin without affecting compatibility with 125 V AC circuits. This is a design improvement in the NANO²®476 series and does not compromise functionality in the original application.

Q: Is 045101.6MRSN a complete replacement for SSQ 1.6/5K? A: 045101.6MRSN is suitable only for AC-only applications. It does not specify a DC voltage rating and has reduced breaking capacity (50A AC vs. 50A AC, 300A DC). For circuits requiring DC operation or higher breaking capacity, use 047601.6MR or 047601.6MRSN instead.

Q: Are all substitute parts RoHS3 compliant? A: Yes. SSQ 1.6/5K and all listed substitutes (047601.6MR, 047601.6MRSN, 045101.6MRSN) are ROHS3 compliant with Moisture Sensitivity Level 1 (Unlimited), meeting environmental and reliability standards.

Q: What is the mechanical compatibility between SSQ 1.6/5K and substitute parts? A: All parts use identical 2-SMD, Square End Block packaging with the same footprint (0.240" L x 0.100"–0.106" W x 0.100"–0.106" H). Direct board-level substitution is supported without PCB redesign.