Equivalent & Substitute Parts for 21FD3740-F Film Capacitor

Part Overview

The Cornell Dubilier Electronics (CDE) 21FD3740-F is a 40 µF film capacitor rated for 370V AC operation with polypropylene (PP) metallized dielectric construction. This radial, can-style component is designed for motor run and power factor correction (PFC) applications in chassis-mounted configurations. The 21FD3740-F carries an obsolete product status, making identification of equivalent and substitute parts essential for system maintenance, repair, and component sourcing continuity.

Substiute Parts

21FD3740-F

Cornell Dubilier Electronics (CDE)In Stock: 71421FD3740-F Datasheet

Current PartRFQ

21FD3740A-F

Cornell Dubilier Electronics (CDE)In Stock: 84321FD3740A-F Datasheet

DirectRFQ

21FD3740

Cornell Dubilier Electronics (CDE)In Stock: 102821FD3740 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 21FD3740-F is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Non-Negotiable):

• Capacitance: 40 µF
• Tolerance: ±10%
• Voltage Rating (AC): 370V
• Dielectric Material: Polypropylene (PP), Metallized

Mechanical Parameters (Non-Negotiable):

• Package / Case: Radial, Can
• Mounting Type: Chassis Mount, Requires Holder/Bracket
• Lead Spacing: 0.813" (20.64mm)
• Termination: Quick Connect, Disconnect

Environmental Parameters:

• Operating Temperature Range: -40°C ~ 70°C
• Moisture Sensitivity Level: 1 (Unlimited)

All substitute parts listed below maintain identical electrical and mechanical specifications. Variations in product status, packaging format, and compliance certifications are noted but do not affect functional interchangeability within the specified application scope.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: 21FD3740A-F

The 21FD3740A-F is the direct manufacturer equivalent with active product status. This part maintains all electrical and mechanical specifications identical to the 21FD3740-F. The 21FD3740A-F carries ROHS3 compliance certification and is available in bulk packaging. The seated height differential of 0.090" (2.28mm) is within typical mechanical tolerance ranges for chassis-mounted can capacitors and does not affect functional interchangeability in standard motor run and PFC applications.

Secondary Substitute: 21FD3740

The 21FD3740 is a parametric equivalent with active product status. This part maintains identical electrical specifications and mechanical dimensions (seated height 4.000" matching the original 21FD3740-F). The 21FD3740 does not carry RoHS3 compliance certification. Selection of this part is appropriate for applications where RoHS compliance is not a regulatory requirement.

Both substitute parts are suitable for direct replacement in motor run and power factor correction circuits where the 21FD3740-F was originally specified.

Frequently Asked Questions (FAQ)

Q: Can the 21FD3740A-F be used as a direct replacement for the 21FD3740-F?

A: Yes. The 21FD3740A-F maintains identical electrical ratings (40 µF, ±10%, 370V AC), dielectric material (polypropylene metallized), and mechanical specifications (radial can package, 0.813" lead spacing, quick connect termination). The 0.090" height difference falls within acceptable mechanical tolerances for chassis-mounted applications.

Q: What is the difference between the 21FD3740A-F and 21FD3740?

A: Both parts are parametric equivalents with identical electrical and core mechanical specifications. The 21FD3740A-F carries ROHS3 compliance certification; the 21FD3740 does not. The 21FD3740A-F is available in bulk packaging, while the 21FD3740 packaging format is not specified. Selection depends on regulatory compliance requirements for your application.

Q: Why is the 21FD3740-F listed as obsolete?

A: The 21FD3740-F has reached end-of-life status with Cornell Dubilier Electronics. The 21FD3740A-F and 21FD3740 remain active products and serve as current production alternatives.

Q: Are there any compatibility concerns with the seated height variation between 21FD3740-F and 21FD3740A-F?

A: The 21FD3740-F has a maximum seated height of 4.000" (101.60mm); the 21FD3740A-F is 4.090" (103.88mm). This 0.090" (2.28mm) difference is typical for can capacitor manufacturing tolerances and does not affect electrical performance or standard chassis mounting configurations.

Q: Can these parts be used in power factor correction (PFC) applications?

A: Yes. All listed parts are rated for power factor correction applications. The 370V AC rating, 40 µF capacitance, and polypropylene metallized dielectric are suitable for PFC circuit requirements.

Q: What is the lead spacing requirement for these capacitors?

A: All listed parts maintain 0.813" (20.64mm) lead spacing. This specification is critical for chassis-mounted holder/bracket compatibility and must be verified during installation.

Q: Are these parts RoHS compliant?

A: The 21FD3740-F and 21FD3740A-F are ROHS3 compliant. The 21FD3740 is RoHS non-compliant. Verify compliance requirements for your specific application before selection.