38FB4450 Film Capacitor 50µF 440VAC Equivalent & Substitute Parts

Part Overview

The 38FB4450 is a 50 µF film capacitor rated for 440V AC operation, manufactured by Cornell Dubilier Electronics (CDE) in the MPF series. This radial, metallized polypropylene capacitor is designed for motor run and power factor correction applications in industrial equipment. The part is currently active in production with 968 units in stock.

Equivalent and substitute parts are identified to provide alternative sourcing options when the primary part number is unavailable, to support inventory management across different packaging formats, or to accommodate design revisions that permit component substitution within specified electrical and mechanical parameters.

Substiute Parts

38FB4450

Cornell Dubilier Electronics (CDE)In Stock: 106138FB4450 Datasheet

Current PartRFQ

SFD44T50K391B-F

Cornell Dubilier Electronics (CDE)In Stock: 784SFD44T50K391B-F Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 38FB4450 is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Non-Negotiable):

• Capacitance: 50 µF (exact match required)
• Voltage Rating - AC: 440V (exact match required)
• Tolerance: ±10% (exact match required)
• Dielectric Material: Polypropylene (PP), Metallized (exact match required)

Mechanical Parameters (Required for Physical Compatibility):

• Mounting Type: Chassis Mount, Requires Holder/Bracket
• Package / Case: Radial, Can
• Termination: Quick Connect, Disconnect

Environmental Parameters (Application-Dependent):

• Operating Temperature Range: -40°C ~ 70°C (substitute must support this range)

Functional Parameters:

• Applications: Motor Run and Power Factor Correction (PFC)

The substitute part SFD44T50K391B-F meets all electrical and mechanical equivalence criteria. Dimensional variations within manufacturing tolerances and differences in compliance certifications do not affect functional substitutability.

Parameter Comparison

Engineering Selection Recommendations

Primary Part (38FB4450): Use when RoHS non-compliance is acceptable for the application and when the MPF series is specified in design documentation. This part is currently in active production with higher inventory availability.

Substitute Part (SFD44T50K391B-F): Use when ROHS3 compliance is required by procurement specifications or regulatory requirements. The SF series provides equivalent electrical and mechanical performance with improved environmental compliance. Dimensional differences are within standard manufacturing tolerances and do not affect mechanical fit in standard chassis mount applications with holder/bracket assemblies.

Both parts are manufactured by the same supplier (Cornell Dubilier Electronics) and share identical electrical specifications, ensuring functional interchangeability in motor run and power factor correction circuits operating at 440V AC with 50 µF capacitance requirements.

Frequently Asked Questions (FAQ)

Q: Can SFD44T50K391B-F be used as a direct replacement for 38FB4450?

A: Yes. Both parts have identical capacitance (50 µF), voltage rating (440V AC), tolerance (±10%), dielectric material (polypropylene metallized), operating temperature range (-40°C to 70°C), mounting type (chassis mount with holder/bracket), package type (radial can), and termination method (quick connect/disconnect). Dimensional variations are within manufacturing tolerances.

Q: What is the difference between the MPF and SF series?

A: The MPF series (38FB4450) and SF series (SFD44T50K391B-F) are both Cornell Dubilier film capacitor lines with identical electrical specifications for this 50 µF 440V application. The primary difference is RoHS compliance status: the SF series is ROHS3 compliant, while the MPF series is not. Both are active production lines.

Q: Are there dimensional differences that affect installation?

A: Dimensional differences exist but are within standard manufacturing tolerances. The 38FB4450 measures 3.654" L x 1.969" W with 4.000" maximum seated height, while the SFD44T50K391B-F measures 3.660" L x 1.970" W with 4.030" maximum seated height. Lead spacing differs by 0.003" (0.813" versus 0.810"). These variations do not affect compatibility with standard chassis mount holder/bracket assemblies.

Q: Which part should be selected for new designs?

A: Selection depends on regulatory and procurement requirements. If ROHS3 compliance is mandated, specify SFD44T50K391B-F. If RoHS compliance is not required, either part is acceptable based on availability and lead time.

Q: Can these parts be used in applications other than motor run and power factor correction?

A: These parts are rated and specified for motor run and power factor correction applications. Use in other applications requires verification that the electrical and thermal characteristics meet the specific circuit requirements.

Q: What is the lead spacing tolerance, and does it affect PCB design?

A: Lead spacing is 0.813" (20.64mm) for 38FB4450 and 0.810" (20.57mm) for SFD44T50K391B-F. Both are designed for chassis mount applications with holder/bracket assemblies rather than direct PCB mounting, so lead spacing tolerance does not affect PCB layout.

Q: Are both parts currently available?

A: Yes. The 38FB4450 has 968 units in stock, and the SFD44T50K391B-F has 768 units in stock, both listed as new original inventory.