RLD30P800UFF Equivalent & Substitute Parts

Part Overview

The RLD30P800UFF is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., part of the POLY-FUSE® RLD30 series. This component is rated for 30V maximum voltage with an 8A hold current and is designed for through-hole radial mounting in disc configuration. The product is currently obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations.

Substiute Parts

RLD30P800UFF

Littelfuse Inc.In Stock: 840RLD30P800UFF Datasheet

Current PartRFQ

30R800UH

Littelfuse Inc.In Stock: 297130R800UH Datasheet

DirectRFQ

30R900UH

Littelfuse Inc.In Stock: 369930R900UH Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the RLD30P800UFF is determined by electrical and mechanical compatibility within the following parameters:

Critical Parameters for Substitution:

• Voltage rating (30V maximum)
• Current hold rating (8A or higher)
• Mounting type (through hole radial)
• Package configuration (radial disc)
• Lead spacing (0.402" / 10.20mm)
• Approval certifications (cURus, TUV)
• RoHS compliance (ROHS3)

Direct Equivalent: The 30R800UH maintains identical electrical specifications (30V, 8A hold current, 16A trip current) and mechanical form factor, with active product status and improved availability.

Manufacturer Recommended Substitute: The 30R900UH provides a higher current hold rating (9A) and trip current (18A) while maintaining the same voltage rating and mechanical compatibility. This part is recommended when circuit protection requirements allow for increased current thresholds.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (RLD30P800UFF → 30R800UH): The 30R800UH is the direct functional equivalent with identical electrical characteristics and mechanical form factor. This part is recommended for applications requiring exact parameter matching. The 30R800UH carries active product status with higher inventory availability and maintains all required certifications (cURus, TUV) and ROHS3 compliance.

For Upgraded Protection (RLD30P800UFF → 30R900UH): The 30R900UH is the manufacturer-recommended substitute when circuit design allows for increased current thresholds. This part provides 1A higher hold current (9A vs 8A) and 2A higher trip current (18A vs 16A) while maintaining voltage compatibility and mechanical fit. The 30R900UH is actively manufactured with superior inventory levels and full compliance certifications.

Both substitute parts are manufactured by Littelfuse Inc. and maintain compatibility with the original mounting footprint and lead spacing specifications.

Frequently Asked Questions (FAQ)

Q: Can the 30R800UH be used as a direct replacement for the RLD30P800UFF? A: Yes. The 30R800UH provides identical electrical specifications (30V, 8A hold current, 16A trip current) and mechanical compatibility. Both parts feature the same radial disc package, lead spacing (0.402"), and operating temperature range (-40°C to 85°C).

Q: What is the difference between the 30R800UH and 30R900UH? A: The primary difference is the current rating. The 30R800UH maintains the original 8A hold current and 16A trip current, while the 30R900UH provides 9A hold current and 18A trip current. Both maintain the same 30V voltage rating and mechanical form factor. The 30R900UH has a slightly longer time-to-trip specification (20s vs 18.8s).

Q: Are all substitute parts mechanically compatible with the original PCB footprint? A: Yes. All listed parts maintain the same lead spacing (0.402" / 10.20mm) and radial disc package configuration. Physical dimensions are compatible with standard through-hole mounting.

Q: Do the substitute parts meet the same compliance requirements? A: Yes. Both 30R800UH and 30R900UH are ROHS3 compliant and carry cURus and TUV approvals, matching the original RLD30P800UFF certifications.

Q: Why is the RLD30P800UFF obsolete? A: The RLD30P800UFF has been superseded by the newer 30R series (30R800UH and 30R900UH) from Littelfuse Inc., which offer improved availability and active manufacturing status.