SSQ 800/1K Equivalent & Substitute Parts

Part Overview

The SSQ 800/1K is an 800 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 equivalent substitute parts essential for ongoing design support and procurement continuity. The fast blow response time and 2-SMD square end block package configuration define its functional role in circuit protection applications. Substitute parts must maintain identical electrical ratings and mechanical compatibility to ensure proper circuit protection performance.

Substiute Parts

SSQ 800/1K

Bel Fuse Inc.In Stock: 876SSQ 800/1K Datasheet

Current PartRFQ

0451.800MRSN

Littelfuse Inc.In Stock: 8110451.800MRSN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SSQ 800/1K is determined by strict alignment of the following critical parameters:

• Current Rating: 800 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 Configuration: 2-SMD, Square End Block
• Physical Dimensions: Compatible with 0.240" L x 0.100" W x 0.100" H footprint tolerance
• Approval Agencies: CSA, cULus, or equivalent recognized certifications

The substitute part 0451.800MRSN (Littelfuse Inc., NANO²® 451 series) meets all mandatory electrical and mechanical criteria for direct substitution. This part maintains identical current and voltage ratings, fast blow response, surface mount configuration, and operates within the same temperature range. Physical dimensions show minor tolerance variation (0.106" W x 0.106" H versus 0.100" W x 0.100" H), which remains within acceptable PCB footprint compatibility for 2-SMD square end block packages.

Parameter Comparison

Engineering Selection Recommendations

The 0451.800MRSN from Littelfuse Inc. is the qualified substitute for the obsolete SSQ 800/1K. Selection is based on the following engineering criteria:

• Electrical equivalence: Identical 800 mA current rating and 125 V AC voltage rating
• Mechanical compatibility: 2-SMD square end block package with compatible footprint dimensions
• Regulatory compliance: Both parts maintain ROHS3 compliance, REACH unaffected status, and EAR99 classification
• Active product status: The 0451.800MRSN is actively manufactured and supported, ensuring long-term availability and supply chain continuity
• Thermal performance: Identical operating temperature range (-55°C ~ 125°C) ensures equivalent thermal behavior in circuit applications
• Certification alignment: CSA and UR certifications on the substitute part provide recognized safety approval for board mount fuse applications

Physical dimension tolerance (0.106" versus 0.100" width and height) represents a minor variation acceptable within standard PCB footprint design margins for 2-SMD packages and does not compromise electrical or mechanical function.

Frequently Asked Questions (FAQ)

Q: Can the 0451.800MRSN be used as a direct replacement for the SSQ 800/1K on existing PCBs?

A: Yes. The 0451.800MRSN maintains identical electrical ratings (800 mA, 125 V AC), fast blow response time, and 2-SMD square end block package configuration. Physical dimensions show minor tolerance variation (±0.006" in width and height) that remains within acceptable PCB footprint compatibility for this package type.

Q: What is the primary reason for substitution?

A: The SSQ 800/1K is classified as obsolete. The 0451.800MRSN is an active product from Littelfuse Inc., ensuring ongoing availability, manufacturing support, and supply chain continuity.

Q: Are there compliance or certification differences between these parts?

A: Both parts are ROHS3 compliant and REACH unaffected. The SSQ 800/1K carries CE, CSA, and cULus certifications. The 0451.800MRSN carries CSA and UR certifications. Both certifications are recognized for board mount fuse applications.

Q: Does the 0451.800MRSN have a DC voltage rating specification?

A: The provided data specifies 125 V AC for the 0451.800MRSN. The SSQ 800/1K is rated for 125 V AC/DC. Verify DC voltage requirements with the component manufacturer or datasheet if DC operation above 125 V is required.

Q: What is the packaging difference between these parts?

A: The SSQ 800/1K is supplied as loose components. The 0451.800MRSN is supplied in Tape & Reel (TR) format, which is standard for high-volume surface mount assembly operations.

Q: Are there any thermal or performance differences?

A: Both parts operate across the identical temperature range (-55°C ~ 125°C) and maintain fast blow response time. The 0451.800MRSN specifies a melting I²t value of 0.271 and DC cold resistance of 0.212 Ohms, providing additional thermal and electrical characterization data for design verification.