16R400GUKL21 Equivalent & Substitute Parts

Part Overview

The 16R400GUKL21 is a PTC resettable fuse in radial configuration manufactured by Littelfuse Inc. This component is classified as obsolete, necessitating identification of active equivalent parts for ongoing design and procurement requirements. PTC resettable fuses provide automatic overcurrent protection by increasing resistance when excessive current is detected, then resetting when the fault condition is removed.

Substiute Parts

16R400GUKL21

Littelfuse Inc.In Stock: 80016R400GUKL21 Datasheet

Current PartRFQ

RGEF400

Littelfuse Inc.In Stock: 7741RGEF400 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The RGEF400 is identified as a direct substitute for the 16R400GUKL21 based on the following substitution criteria:

Electrical Parameters:

• Voltage rating: 16V maximum
• Current hold (Ih): 4A
• Polymeric PTC resettable fuse technology

Mechanical Parameters:

• Mounting type: Through hole radial configuration
• Package form: Radial, disc geometry

Compliance Parameters:

• RoHS3 compliance maintained
• Same ECCN classification (EAR99)
• Same HTSUS code (8533.40.8070)
• Manufacturer: Littelfuse Inc.

Product Status:

• RGEF400 is active and in production, providing long-term availability

Parameter Comparison

Engineering Selection Recommendations

The RGEF400 is the appropriate substitute for the obsolete 16R400GUKL21 based on the following engineering criteria:

Compliance Alignment:

• Both components maintain ROHS3 compliance, ensuring regulatory compatibility in restricted substance applications
• Identical ECCN and HTSUS classifications confirm export control and tariff consistency

Manufacturer Continuity:

• Both components are manufactured by Littelfuse Inc., ensuring consistent design philosophy and quality standards

Functional Equivalence:

• The RGEF400 operates at identical voltage and current hold ratings (16V, 4A), providing direct functional replacement
• Through-hole radial mounting configuration matches the original design form factor

Availability and Support:

• The RGEF400 is in active production status with substantial inventory availability, eliminating obsolescence risk associated with the 16R400GUKL21

Frequently Asked Questions (FAQ)

Q: Can the RGEF400 be used as a direct replacement for the 16R400GUKL21 in existing designs?

A: Yes. Both components share identical voltage (16V) and current hold (4A) ratings, matching mounting type (through-hole radial), and equivalent compliance certifications (ROHS3, EAR99). The RGEF400 is functionally equivalent for applications designed around the 16R400GUKL21 specifications.

Q: What is the primary reason for substitution?

A: The 16R400GUKL21 is classified as obsolete. The RGEF400 is an active product from the same manufacturer, providing long-term availability and supply chain continuity.

Q: Are there any differences in physical dimensions between these parts?

A: The RGEF400 provides detailed dimensional specifications: 0.331" L x 0.098" W (8.40mm x 2.50mm) with a maximum seated height of 0.504" (12.80mm) and lead spacing of 0.199" (5.05mm). The 16R400GUKL21 dimensional data is not provided in the available documentation. Physical verification is necessary if space constraints are critical to the application.

Q: Are the packaging formats compatible?

A: The RGEF400 is supplied in bag packaging. The 16R400GUKL21 packaging format is not specified. Confirm packaging requirements with procurement specifications before finalizing the substitution.

Q: Do both components have the same regulatory approvals?

A: Both components are ROHS3 compliant and carry the same ECCN (EAR99) and HTSUS (8533.40.8070) classifications. The RGEF400 carries CSA, TUV, and UL approvals. Approval agency information for the 16R400GUKL21 is not provided.

Q: What is the difference between Current Hold (Ih) and Current Trip (It)?

A: Current Hold (Ih) is the maximum continuous current the fuse can carry without tripping, specified as 4A for the RGEF400. Current Trip (It) is the threshold at which the fuse activates protection, specified as 6.8A for the RGEF400. The trip current is approximately 1.7 times the hold current.