SSQ 315/5K Equivalent & Substitute Parts

Part Overview

The SSQ 315/5K is a 315 mA surface mount board mount fuse rated for 125 V AC/DC operation, manufactured by Bel Fuse Inc. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and procurement continuity. The fast blow response time and 2-SMD square end block package are critical functional characteristics that define the substitution scope.

Substiute Parts

SSQ 315/5K

Bel Fuse Inc.In Stock: 835SSQ 315/5K Datasheet

Current PartRFQ

0451.315MRSN

Littelfuse Inc.In Stock: 10840451.315MRSN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SSQ 315/5K is determined by strict alignment across the following parameters:

• Current Rating: 315 mA (exact match required)
• Voltage Rating: 125 V AC minimum; DC rating of 125 V or higher
• Response Time: Fast Blow
• Mounting Type: Surface Mount
• Package / Case: 2-SMD, Square End Block
• Operating Temperature Range: -55°C ~ 125°C minimum
• RoHS Compliance: ROHS3 Compliant

The substitute part 0451.315MRSN (Littelfuse Inc., NANO²® 451 series) meets all substitution criteria. This part maintains identical current and voltage ratings, fast blow response, surface mount configuration, and compatible package dimensions within tolerance.

Parameter Comparison

Engineering Selection Recommendations

The 0451.315MRSN from Littelfuse Inc. is the qualified substitute for the obsolete SSQ 315/5K. Selection is based on:

• Functional equivalence across all critical electrical parameters (current, voltage, response time)
• Mechanical compatibility within package tolerance (width and height variance of 0.006" / 0.15mm)
• Active product status ensuring long-term availability and supply chain continuity
• Equivalent regulatory compliance (ROHS3, CSA, UR certifications)
• Identical operating temperature range and moisture sensitivity classification

The substitute part is suitable for direct replacement in existing designs without circuit modification.

Frequently Asked Questions (FAQ)

Q: Can the 0451.315MRSN be used as a direct replacement for the SSQ 315/5K?

A: Yes. Both parts share identical current rating (315 mA), voltage rating (125 V AC), response time (Fast Blow), mounting type (Surface Mount), and package configuration (2-SMD, Square End Block). Dimensional variance is within acceptable tolerance for PCB footprint compatibility.

Q: What is the significance of the product status difference (Obsolete vs. Active)?

A: The SSQ 315/5K is obsolete and no longer manufactured by Bel Fuse Inc. The 0451.315MRSN is an active product with ongoing production and supply availability, making it the appropriate choice for new procurement and design continuity.

Q: Are there dimensional differences between these parts?

A: Minor dimensional variance exists in width and height (0.006" / 0.15mm difference). Both parts maintain the same length (0.240" / 6.10mm) and are designed for the same 2-SMD, Square End Block footprint. Standard PCB design tolerances accommodate this variance.

Q: What certifications apply to the substitute part?

A: The 0451.315MRSN holds CSA and UR approvals. The original SSQ 315/5K held CE, CSA, and cULus approvals. Verify that the substitute certifications meet your specific application requirements.

Q: Is DC voltage rating specified for the substitute part?

A: The 0451.315MRSN datasheet specifies 125 V AC operation. DC rating is not explicitly provided in the available parameters. Confirm DC voltage compatibility with Littelfuse technical documentation if DC operation is required.