Equivalent & Substitute Parts for RLD30P500UFF

Part Overview

The RLD30P500UFF 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 a 5A hold current and is designed for through-hole radial mounting in disc configuration. The product is currently obsolete, making identification of suitable equivalent and substitute parts essential for ongoing maintenance, repair, and legacy system support.

Substiute Parts

RLD30P500UFF

Littelfuse Inc.In Stock: 1118RLD30P500UFF Datasheet

Current PartRFQ

30R500UF

Littelfuse Inc.In Stock: 1297730R500UF Datasheet

DirectRFQ

30R600UF

Littelfuse Inc.In Stock: 725830R600UF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the RLD30P500UFF is determined by strict alignment of electrical and mechanical parameters. The following criteria establish valid substitute relationships:

Primary Substitution Criteria:

• Voltage rating must equal or exceed 30V maximum
• Mounting type must be through-hole radial disc configuration
• Lead spacing must match 0.402" (10.20mm)
• Operating temperature range must encompass -40°C ~ 85°C
• Approval agencies must include cURus and TUV certifications
• RoHS3 compliance is required

Current Rating Considerations: Hold current (Ih) and trip current (It) values define the protection threshold. Substitutes with identical or higher current ratings maintain equivalent protection characteristics within the same voltage class.

Parameter Comparison

Engineering Selection Recommendations

30R500UF - Direct Substitute: The 30R500UF is the primary equivalent for RLD30P500UFF replacement. Both components share identical electrical specifications: 30V maximum voltage, 5A hold current, 10A trip current, and matching resistance characteristics. The 30R500UF maintains active product status with full cURus and TUV certification. Physical dimensions are nearly identical with only minor height variation (1.008" vs 0.980"). This substitute provides direct functional equivalence with improved availability.

30R600UF - Manufacturer Recommended Alternative: The 30R600UF is the manufacturer-recommended substitute when 30R500UF is unavailable. This component operates at the same 30V voltage rating but provides higher current protection with 6A hold current and 12A trip current. The 30R600UF features improved initial resistance (5 mOhms vs 10 mOhms) and lower post-trip resistance (40 mOhms vs 50 mOhms), resulting in reduced power dissipation. Physical dimensions are larger (0.650" L vs 0.551" L), requiring verification of available board space. This substitute is suitable for applications where higher current protection is acceptable or beneficial.

Both substitutes maintain ROHS3 compliance and full regulatory certifications required for the original component.

Frequently Asked Questions (FAQ)

Q: Can 30R500UF directly replace RLD30P500UFF without circuit modification? A: Yes. The 30R500UF provides identical electrical specifications and equivalent physical dimensions. No circuit modifications are required for direct substitution.

Q: What is the difference between 30R500UF and 30R600UF? A: The primary difference is current rating. The 30R500UF maintains the original 5A hold current specification, while the 30R600UF provides 6A hold current with corresponding 12A trip current. The 30R600UF also features lower resistance values. Selection depends on circuit protection requirements and available board space.

Q: Are there physical space constraints when using 30R600UF? A: Yes. The 30R600UF is physically larger (0.650" L x 0.118" W) compared to RLD30P500UFF (0.551" L x 0.118" W). Verify available board space before substitution. Lead spacing remains identical at 0.402" (10.20mm).

Q: Do both substitutes maintain the same regulatory certifications? A: Yes. Both 30R500UF and 30R600UF carry cURus and TUV approvals and are ROHS3 compliant, matching the original RLD30P500UFF certifications.

Q: Why is RLD30P500UFF obsolete? A: The RLD30P500UFF has been superseded by the active 30R series components (30R500UF and 30R600UF), which offer improved performance characteristics and continued manufacturing support.