21FD3703-F Film Capacitor 3µF 370VAC Radial

Part Overview

The Cornell Dubilier Electronics (CDE) 21FD3703-F is a 3 µF film capacitor rated for 370V AC, designed with polypropylene (PP) metallized dielectric in a radial, can-style package. This component is classified as obsolete product status, making alternative sources necessary for new production and maintenance applications. The part is commonly used in motor run and power factor correction (PFC) circuits where stable capacitance and reliable performance across the specified temperature range (-40°C to 70°C) are required.

Substiute Parts

21FD3703-F

Cornell Dubilier Electronics (CDE)In Stock: 77321FD3703-F Datasheet

Current PartRFQ

21FD3703A-F

Cornell Dubilier Electronics (CDE)In Stock: 90321FD3703A-F Datasheet

DirectRFQ

SFP37T3K238B-F

Cornell Dubilier Electronics (CDE)In Stock: 1198SFP37T3K238B-F Datasheet

DirectRFQ

SFP44T3K238B-F

Cornell Dubilier Electronics (CDE)In Stock: 669SFP44T3K238B-F Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Direct substitution for the 21FD3703-F is established based on strict equivalence in the following key parameters: capacitance (3 µF), tolerance (±10%), voltage rating (370V AC), dielectric material (polypropylene metallized), and mounting type (chassis mount radial can). Two substitute parts meet these criteria without exception:

Group 1 - Direct AC Voltage Equivalents (370V):

• 21FD3703A-F: Active product status equivalent with identical electrical specifications and mounting characteristics. Height difference (2.630" vs. 2.880") is within chassis mount installation tolerances.
• SFP37T3K238B-F: Active product from the SF series with matching electrical parameters. Minor dimensional variations in diameter (1.870" vs. 1.875") and height (2.500" vs. 2.880") remain compatible with standard holder/bracket installations.

Group 2 - Higher Voltage Rating (440V AC):

• SFP44T3K238B-F: 440V AC rated variant with identical 3 µF capacitance and ±10% tolerance. This part provides overvoltage margin relative to the original 370V specification and is mechanically compatible. Substitution is valid only in applications where the 440V rating does not create cost or form-factor constraints.

Substitution is determined solely by matching capacitance, tolerance, dielectric type, and mounting configuration. All substitute parts maintain ROHS3 compliance and are actively manufactured by Cornell Dubilier Electronics.

Parameter Comparison

Engineering Selection Recommendations

The 21FD3703-F, classified as obsolete, requires substitution for ongoing procurement. Both 21FD3703A-F and SFP37T3K238B-F provide direct electrical equivalence at 370V AC with active product status. The 21FD3703A-F maintains identical dimensions and is the preferred choice for direct replacement without mechanical redesign. The SFP37T3K238B-F, from the SF series, offers equivalent performance with minor dimensional reductions suitable for space-constrained installations.

The SFP44T3K238B-F (440V variant) is electrically compatible and provides additional voltage margin in applications where system voltage tolerance permits. This part is applicable only when the 440V rating aligns with circuit design specifications and cost objectives.

All substitute options maintain ROHS3 compliance, matching the environmental requirements of the original part.

Frequently Asked Questions (FAQ)

Q: Can the 21FD3703A-F directly replace the 21FD3703-F without any modifications? A: Yes. The 21FD3703A-F matches all critical electrical parameters (3 µF, ±10% tolerance, 370V AC, polypropylene metallized dielectric) and mounting characteristics (chassis mount, radial can, quick connect/disconnect termination). The only difference is product status—obsolete versus active—and a minor height reduction (2.630" versus 2.880"), which is compatible with standard holder/bracket installations.

Q: What is the difference between the 370V and 440V variants? A: The SFP44T3K238B-F is rated for 440V AC compared to 370V AC for the main part and other substitutes. Both maintain identical 3 µF capacitance and ±10% tolerance. The 440V rating provides overvoltage protection margin but should only be selected if the application permits higher voltage ratings without cost or space penalties.

Q: Are there any dimensional constraints I should consider when selecting a substitute? A: Minor dimensional differences exist among the substitutes. The 21FD3703A-F maintains the original diameter (1.875") but is 0.250" shorter. The SFP37T3K238B-F and SFP44T3K238B-F are both approximately 0.005" smaller in diameter and 0.380" to 0.380" shorter. All variants are compatible with standard chassis mount holders/brackets. Verify available space in your application if height or diameter constraints are critical.

Q: Are all substitute parts ROHS3 compliant? A: Yes. The 21FD3703A-F, SFP37T3K238B-F, and SFP44T3K238B-F all carry ROHS3 compliance certification, matching the environmental standards of the original obsolete part.

Q: Can I use the SFP37T3K238B-F in a motor run or PFC application? A: The SFP37T3K238B-F is electrically suitable for motor run applications based on its 3 µF capacitance, 370V AC rating, and polypropylene metallized dielectric. While the documented applications for this part list motor run only, the electrical specifications and dielectric properties support PFC functionality if circuit design requirements are met.