RLD30P600UFF Equivalent & Substitute Parts

Part Overview

The RLD30P600UFF is a polymeric PTC resettable fuse manufactured by Littelfuse, part of the POLY-FUSE® RLD30 series. This through-hole radial disc component provides overcurrent protection at 30V with a 6A hold current rating. The product is currently obsolete, making equivalent substitutes necessary for ongoing system maintenance, repairs, and legacy design support. Substitute parts must maintain electrical equivalence across voltage, current, and thermal characteristics while accommodating available packaging and certification requirements.

Substiute Parts

RLD30P600UFF

LittelfuseIn Stock: 1235RLD30P600UFF Datasheet

Current PartRFQ

30R600UF

Littelfuse Inc.In Stock: 725830R600UF Datasheet

DirectRFQ

RUEF600-AP

LittelfuseIn Stock: 1260RUEF600-AP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RLD30P600UFF is determined by strict equivalence across the following critical parameters:

• Voltage Rating: Maximum voltage must be 30V or greater
• Current - Hold (Ih): Must be rated at 6A maximum
• Current - Trip (It): Must be 12A
• Resistance - Initial (Ri): Minimum 5 mOhms
• Resistance - Post Trip (R1): Maximum 40 mOhms
• Operating Temperature: Must support -40°C to 85°C range
• Mounting Type: Through Hole configuration required
• Package / Case: Radial, Disc form factor required
• Lead Spacing: Nominal 0.402 inches (10.20mm) with tolerance
• Regulatory Compliance: RoHS3 compliance required

The two identified substitutes—30R600UF and RUEF600-AP—meet all electrical and mechanical equivalence criteria. Both are polymeric PTC resettable fuses manufactured by Littelfuse with identical voltage, hold current, trip current, and resistance specifications. Differences in product status, packaging format, and approval agencies are noted for procurement and application-specific selection.

Parameter Comparison

Engineering Selection Recommendations

Both 30R600UF and RUEF600-AP are electrically and mechanically equivalent to the obsolete RLD30P600UFF across all critical protection parameters. Selection between the two substitutes is based on product availability, packaging requirements, and regulatory certification scope:

30R600UF is the primary substitute. It maintains active product status within the POLY-FUSE® 30R series, carries identical electrical specifications, and is available in bulk packaging. Certifications include cURus and TUV approval. This part is recommended for standard applications requiring high inventory availability.

RUEF600-AP is an alternative substitute from the PolySwitch® RUEF series. It provides equivalent electrical performance with a higher maximum current rating (100A vs. 40A), broader regulatory approval (CQC, CSA, TUV, UL), and is available in Cut Tape packaging. This part is suitable for applications requiring extended certification coverage or tape-and-reel assembly processes. Seated height and lead spacing show minor dimensional variation within acceptable tolerance ranges for through-hole radial disc components.

Both substitutes are ROHS3 compliant and maintain the same operating temperature range, making them suitable for direct replacement in legacy system repairs and ongoing production support.

Frequently Asked Questions (FAQ)

Q: Can 30R600UF or RUEF600-AP be used as direct replacements for RLD30P600UFF in existing designs?

A: Yes. Both substitutes meet all electrical equivalence criteria: 30V maximum voltage, 6A hold current, 12A trip current, 5 mOhms initial resistance, and 40 mOhms post-trip resistance. Through-hole radial disc mounting and lead spacing are compatible with standard PCB layouts designed for the RLD30P600UFF.

Q: What is the difference between the two substitute parts?

A: The primary differences are product series designation (POLY-FUSE® 30R vs. PolySwitch® RUEF), maximum current rating (40A vs. 100A), regulatory approvals (cURus/TUV vs. CQC/CSA/TUV/UL), and packaging format (Bulk vs. Cut Tape). Electrical protection characteristics are identical.

Q: Are there dimensional compatibility concerns?

A: Seated height varies slightly: RLD30P600UFF at 0.980", 30R600UF at 1.055", and RUEF600-AP at 0.949". Lead spacing is 0.402" (10.20mm) for both substitutes versus 0.402" for the main part, with RUEF600-AP at 0.400" (10.15mm). These variations are within acceptable tolerance for through-hole radial disc components and do not affect PCB assembly compatibility.

Q: Which substitute should be selected for new production?

A: 30R600UF is recommended for standard applications due to active product status and established supply chain. RUEF600-AP is preferred when broader regulatory certifications (UL, CSA, CQC) are required or when tape-and-reel packaging is specified for automated assembly.

Q: Are both substitutes RoHS3 compliant?

A: Yes. Both 30R600UF and RUEF600-AP are ROHS3 compliant, meeting environmental and material restriction requirements equivalent to the obsolete RLD30P600UFF.