21FD3725-F Film Capacitor 25µF 370VAC Equivalent & Substitute Parts

Part Overview

The 21FD3725-F is a 25 µF film capacitor rated for 370V AC operation, manufactured by Cornell Dubilier Electronics (CDE) in the MPF series. This component is classified as obsolete, though 1142 pieces remain in current inventory. The part is designed for motor run and power factor correction (PFC) applications, utilizing polypropylene metallized dielectric technology in a radial can configuration with quick connect/disconnect termination.

Due to the obsolete product status of the 21FD3725-F, identification of equivalent and substitute parts is necessary for ongoing procurement, maintenance, and system design continuity. Active production alternatives with identical electrical specifications are available from the same manufacturer.

Substiute Parts

21FD3725-F

Cornell Dubilier Electronics (CDE)In Stock: 123821FD3725-F Datasheet

Current PartRFQ

21FD3725A-F

Cornell Dubilier Electronics (CDE)In Stock: 91021FD3725A-F Datasheet

DirectRFQ

SFP37T25K284B-F

Cornell Dubilier Electronics (CDE)In Stock: 1139SFP37T25K284B-F Datasheet

DirectRFQ

21FD3725

Cornell Dubilier Electronics (CDE)In Stock: 116021FD3725 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 21FD3725-F is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

• Capacitance: 25 µF (exact match required)
• Tolerance: ±10% (exact match required)
• Voltage Rating (AC): 370V (exact match required)
• Dielectric Material: Polypropylene (PP), Metallized (exact match required)
• Operating Temperature Range: -40°C to 70°C (exact match required)

Mechanical Compatibility Criteria:

• Package / Case: Radial, Can (exact match required)
• Mounting Type: Chassis Mount, Requires Holder/Bracket (exact match required)
• Termination Type: Quick Connect, Disconnect (exact match required)
• Lead Spacing: 0.813" (20.64mm) nominal (minor dimensional variance acceptable within manufacturing tolerance)

Dimensional Tolerance:

• Height and diameter dimensions may vary within standard manufacturing tolerances provided the component fits within the mechanical envelope of the original application

Substitute parts are grouped into two categories: Direct Manufacturer Substitutes (active production equivalents) and Parametric Equivalents (same electrical specifications, minor packaging or compliance differences).

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: 21FD3725A-F

The 21FD3725A-F is the direct manufacturer equivalent of the 21FD3725-F. Both parts share identical electrical specifications (25 µF, ±10%, 370V AC, polypropylene metallized dielectric) and mechanical configuration (radial can, quick connect/disconnect termination). The 21FD3725A-F is currently in active production status, ensuring long-term availability. The primary dimensional difference is a reduced seated height (3.090" versus 3.250"), which is acceptable for most applications where the original component fits within a defined mechanical envelope. Both parts are ROHS3 compliant. The 21FD3725A-F is supplied in bulk packaging.

Secondary Substitute: SFP37T25K284B-F

The SFP37T25K284B-F is an active production alternative from the SF series with identical electrical specifications. This part maintains the same capacitance, tolerance, voltage rating, and dielectric material as the 21FD3725-F. The SFP37T25K284B-F features a slightly reduced diameter (1.870" versus 1.875") and seated height (3.000" versus 3.250"), with lead spacing of 0.810" (20.57mm) compared to 0.813" (20.64mm). These dimensional variations fall within standard manufacturing tolerances for radial can film capacitors and do not affect electrical performance. The SFP37T25K284B-F is ROHS3 compliant and supplied in bulk packaging.

Parametric Equivalent: 21FD3725

The 21FD3725 (without suffix) is electrically and mechanically identical to the 21FD3725-F, with identical dimensions and lead spacing. This part is currently in active production status. However, the 21FD3725 is RoHS non-compliant, whereas the 21FD3725-F is ROHS3 compliant. Selection of the 21FD3725 is appropriate only for applications where RoHS compliance is not a regulatory requirement.

Selection Basis:

For new designs and applications requiring RoHS3 compliance, the 21FD3725A-F is the recommended primary substitute. For applications where mechanical envelope constraints are minimal, the SFP37T25K284B-F provides an alternative from the active SF series. The 21FD3725 is suitable only for legacy systems where RoHS compliance is not mandated.

Frequently Asked Questions (FAQ)

Q: Can the 21FD3725A-F be used as a direct replacement for the 21FD3725-F?

A: Yes. The 21FD3725A-F is electrically and mechanically equivalent to the 21FD3725-F. Both parts have identical capacitance (25 µF), tolerance (±10%), voltage rating (370V AC), dielectric material (polypropylene metallized), operating temperature range (-40°C to 70°C), and termination type (quick connect/disconnect). The 21FD3725A-F has a reduced seated height (3.090" versus 3.250"), which is acceptable in applications where the original component fits within the mechanical envelope.

Q: What is the difference between the 21FD3725A-F and SFP37T25K284B-F?

A: Both parts are electrically equivalent with identical capacitance, tolerance, voltage rating, and dielectric material. The primary differences are series designation (MPF versus SF) and minor dimensional variations. The SFP37T25K284B-F has a slightly smaller diameter (1.870" versus 1.875") and reduced seated height (3.000" versus 3.090"), with lead spacing of 0.810" versus 0.813". These dimensional differences fall within standard manufacturing tolerances for radial can capacitors and do not affect electrical performance or compatibility with standard quick connect/disconnect termination systems.

Q: Is the 21FD3725 (without suffix) a suitable substitute?

A: The 21FD3725 is electrically and mechanically identical to the 21FD3725-F with no dimensional differences. However, the 21FD3725 is RoHS non-compliant, whereas the 21FD3725-F is ROHS3 compliant. Use the 21FD3725 only in applications where RoHS compliance is not required.

Q: Are all substitute parts ROHS3 compliant?

A: The 21FD3725A-F and SFP37T25K284B-F are both ROHS3 compliant. The 21FD3725 is RoHS non-compliant. For applications requiring RoHS3 compliance, select either the 21FD3725A-F or SFP37T25K284B-F.

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

A: Yes. All substitute parts are rated for motor run and power factor correction applications. The 21FD3725A-F explicitly lists both applications. The SFP37T25K284B-F lists motor run applications. All parts utilize polypropylene metallized dielectric technology suitable for these applications.

Q: What is the significance of the quick connect/disconnect termination?

A: All parts feature quick connect/disconnect termination, which allows connection to standard quick-connect terminals without soldering. This termination type is consistent across all substitute parts and the original component, ensuring compatibility with existing mechanical and electrical interfaces.

Q: Are there any inventory considerations when selecting a substitute?

A: Current inventory levels are: 21FD3725-F (1142 pcs), 21FD3725A-F (873 pcs), SFP37T25K284B-F (1105 pcs), and 21FD3725 (1085 pcs). All parts are available in new original condition. Inventory levels may change; verify current availability with your supplier.

Q: What is the lead spacing tolerance for these parts?

A: The 21FD3725-F, 21FD3725A-F, and 21FD3725 have lead spacing of 0.813" (20.64mm). The SFP37T25K284B-F has lead spacing of 0.810" (20.57mm). This 0.003" (0.07mm) difference is within standard manufacturing tolerances for radial can capacitors and does not affect compatibility with standard quick connect/disconnect terminal systems.