RUEF700K-2 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The RUEF700K-2 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc. in the PolySwitch® RUEF series. This component is rated for 30V maximum voltage with a 7A hold current and 14A trip current, designed for through-hole radial mounting in disc configuration. The part is currently active in production with 3590 units in stock.

Substitute parts are identified when they maintain identical electrical specifications (voltage, current ratings, trip characteristics, and resistance parameters) and compatible mechanical form factors. Alternative sources and packaging options may be required due to inventory availability, supply chain considerations, or specific procurement requirements.

Substiute Parts

RUEF700K-2

Littelfuse Inc.In Stock: 3666RUEF700K-2 Datasheet

Current PartRFQ

RUEF700-2

Littelfuse Inc.In Stock: 5297RUEF700-2 Datasheet

DirectRFQ

PTR030V0700-TR

Eaton - Electronics DivisionIn Stock: 1081PTR030V0700-TR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the RUEF700K-2 is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Requirements:

• Voltage rating: 30V maximum
• Hold current (Ih): 7A maximum
• Trip current (It): 14A
• Initial resistance (Ri): 5 mOhms minimum
• Post-trip resistance (R1): 30 mOhms maximum
• Time to trip: 17.5 seconds
• Operating temperature range: -40°C to 85°C

Mechanical Compatibility Requirements:

• Mounting type: Through hole
• Package configuration: Radial, disc
• Lead spacing tolerance: ±0.015" (±0.38mm) from 0.400" (10.15mm)
• Physical dimensions: 0.752" L x 0.118" W (19.10mm x 3.00mm)

Compliance Requirements:

• RoHS3 compliance mandatory
• Regulatory approvals: CQC, CSA, TUV, UL preferred

Two substitute parts meet these criteria with minor mechanical variations within acceptable tolerances.

Parameter Comparison

Engineering Selection Recommendations

RUEF700-2 (Littelfuse Inc.): This substitute maintains identical electrical specifications and mechanical dimensions as the RUEF700K-2. Both parts are from the same manufacturer series (PolySwitch® RUEF) with equivalent certifications (CQC, CSA, TUV, UL). The primary difference is packaging format (Cut Tape vs. Cut Tape) and seated height variation of 0.071" (1.80mm), which remains within acceptable PCB assembly tolerances. This part is preferred for direct substitution when Littelfuse inventory is prioritized. Higher inventory availability (5229 units) supports supply chain continuity.

PTR030V0700-TR (Eaton - Electronics Division): This substitute provides electrical equivalence across all critical parameters with compatible mechanical form factor. The lead spacing is 0.394" (10.00mm) versus 0.400" (10.15mm) on the primary part, representing a 0.006" (0.15mm) tolerance variation acceptable for through-hole PCB mounting. Seated height is 1.051" (26.70mm), within 0.040" (1.02mm) of the primary part. Packaging is Tape & Reel (TR) format, suitable for automated assembly processes. Regulatory approvals include cURus and TUV certifications. This part is suitable when cross-manufacturer sourcing is required or when Tape & Reel packaging is specified for production assembly.

Both substitutes are active products with current manufacturing status and full RoHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can RUEF700-2 be used as a direct replacement for RUEF700K-2 in existing designs?

A: Yes. Both parts share identical electrical specifications (30V, 7A hold, 14A trip, 17.5s trip time) and mechanical dimensions (0.752" x 0.118", 0.400" lead spacing). The seated height difference of 0.071" (1.80mm) is within standard PCB assembly tolerances and does not affect circuit performance or board layout compatibility.

Q: What is the significance of the lead spacing difference between RUEF700K-2 and PTR030V0700-TR?

A: The PTR030V0700-TR has 0.394" (10.00mm) lead spacing versus 0.400" (10.15mm) on the RUEF700K-2. This 0.006" (0.15mm) difference is within standard through-hole PCB tolerance ranges and does not require PCB redesign. Both parts are mechanically compatible with standard 0.400" pitch PCB footprints.

Q: Are there differences in regulatory approvals between these parts?

A: RUEF700K-2 and RUEF700-2 carry identical approvals (CQC, CSA, TUV, UL). PTR030V0700-TR carries cURus and TUV approvals. All three parts are RoHS3 compliant. Selection should be based on specific regulatory requirements for your application region.

Q: What packaging format should I specify for automated assembly?

A: RUEF700K-2 and RUEF700-2 are supplied in Cut Tape (CT) format. PTR030V0700-TR is supplied in Tape & Reel (TR) format, which is optimized for automated pick-and-place assembly processes. Specify PTR030V0700-TR if your production line requires Tape & Reel packaging.

Q: Are all three parts electrically interchangeable in circuit operation?

A: Yes. All three parts maintain identical electrical performance: 30V maximum voltage, 7A hold current, 14A trip current, 17.5 second trip time, 5 mOhms initial resistance, and 30 mOhms maximum post-trip resistance. Operating temperature range is -40°C to 85°C for all parts.