Molex 0387800421 Equivalent & Substitute Parts

Part Overview

The Molex 0387800421 is a 21-circuit barrier block connector with 0.438" (11.12mm) pitch, designed for chassis and panel mounting applications. This component features dual-wall barrier construction, flange mounting, and a current rating of 20A at 300V. The part is classified as obsolete, making identification of suitable substitutes essential for ongoing system maintenance and new design implementations. The availability of active equivalent models ensures continuity in component sourcing and system reliability.

Substiute Parts

0387800421

MolexIn Stock: 7740387800421 Datasheet

Current PartRFQ

0387800121

MolexIn Stock: 8460387800121 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Molex 0387800421 is determined by the following critical parameters:

Primary Matching Criteria:

• Terminal block type: Barrier Block
• Number of circuits: 21
• Pitch: 0.438" (11.12mm)
• Number of rows: 2
• Barrier type: 2 Wall (Dual)
• Voltage rating: 300V
• Mounting type: Chassis, Panel
• Material flammability rating: UL94 V-0
• RoHS compliance: ROHS3 Compliant

Secondary Compatibility Factors:

• Current rating: 20A (main part) vs. 15A (substitute)
• Top termination: Screws configuration
• Bottom termination: Closed
• Series: Beau 38780

The substitute part Molex 0387800121 maintains all primary matching criteria and series designation. The reduction in current rating from 20A to 15A represents the primary electrical difference and must be evaluated against application requirements.

Parameter Comparison

Engineering Selection Recommendations

The Molex 0387800121 is the designated manufacturer substitute for the obsolete 0387800421. Both components share identical mechanical and electrical specifications within the Beau 38780 series, with the exception of current rating capacity.

Selection Basis:

The 0387800121 maintains active product status, ensuring ongoing availability and manufacturer support. Both parts comply with ROHS3 requirements and achieve UL94 V-0 flammability certification. The substitute part provides documented wire gauge specifications (14-22 AWG) and includes screws as standard, whereas the main part lists screws as not included.

The current rating differential (20A vs. 15A) is the primary technical consideration. Applications operating at or below 15A can utilize the substitute without electrical derating. Applications requiring the full 20A capacity of the original part must evaluate whether the 15A rating of the substitute meets system requirements.

Frequently Asked Questions (FAQ)

Q: Can the Molex 0387800121 directly replace the 0387800421 in all applications?

A: Direct replacement is possible for applications operating at 15A or below. The substitute maintains identical mechanical form factor, pitch, circuit count, voltage rating, and mounting configuration. Applications requiring 20A operation must assess whether the reduced current rating is acceptable for the specific circuit design.

Q: What is the significance of the current rating difference between these parts?

A: The main part (0387800421) is rated for 20A, while the substitute (0387800121) is rated for 15A. This difference reflects the electrical capacity of each component. Selection depends on the actual current requirements of the connected circuits. If circuit current does not exceed 15A per connection, the substitute is suitable.

Q: Are there packaging differences between these parts?

A: The main part packaging is listed as unspecified, while the substitute is supplied in bulk packaging. Both parts are from the same manufacturer series and maintain identical terminal block specifications.

Q: Do both parts include mounting screws?

A: The main part (0387800421) lists screws as not included. The substitute (0387800121) includes screws as part of the standard package. Verify screw requirements for your application.

Q: Are both parts RoHS and flammability compliant?

A: Yes. Both the 0387800421 and 0387800121 are ROHS3 compliant and meet UL94 V-0 flammability requirements, ensuring compliance with environmental and safety standards.

Q: What wire gauges are compatible with the substitute part?

A: The substitute (0387800121) accommodates 14-22 AWG wire. The main part does not specify wire gauge in the provided data. Verify that your wire gauge falls within the 14-22 AWG range for the substitute.