FN258-250-40 Equivalent & Substitute Parts

Part Overview

The FN258-250-40 is a three-phase delta EMC/EMI line filter rated for 250 A with two-stage configuration and terminal block termination. This component is classified as Not For New Designs, making identification of functionally equivalent alternatives essential for ongoing system maintenance and legacy design support. The filter is designed for inverters and power drive systems operating across DC to 60 Hz frequency ranges.

Substiute Parts

FN258-250-40

Schaffner EMC Inc.In Stock: 1047FN258-250-40 Datasheet

Current PartRFQ

FN3359-250-28

Schaffner EMC Inc.In Stock: 1157FN3359-250-28 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FN258-250-40 is determined by the following critical parameters:

• Three-phase delta filter topology
• 250 A current rating
• Chassis mount configuration
• Operating frequency range DC ~ 60Hz
• Compliance certifications (CSA, ENEC, UR)
• RoHS3 compliance

The FN3359-250-28 qualifies as a functional equivalent based on matching filter type, current rating, frequency range, mounting type, and regulatory compliance. Differences in configuration (three-stage vs. two-stage), termination style (threaded post vs. terminal block), and voltage ratings must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

The FN3359-250-28 is the designated substitute for the FN258-250-40. Both components share identical current ratings, filter topology, frequency operating range, and chassis mount configuration. The FN3359-250-28 maintains active product status, ensuring continued availability and support.

Key considerations for selection:

• The FN3359-250-28 features higher voltage ratings (300 V phase-to-ground, 520 V phase-to-phase) compared to the FN258-250-40 (277 V, 480 V), providing additional voltage margin in applications operating at or near rated levels.
• The three-stage configuration of the FN3359-250-28 provides enhanced filtering performance relative to the two-stage design of the FN258-250-40.
• Termination style differs: FN258-250-40 uses terminal block connections while FN3359-250-28 uses threaded post (M10) termination, requiring mechanical interface adaptation.
• Both components hold ROHS3 compliance and ENEC certification. The FN3359-250-28 holds cURus certification while the FN258-250-40 holds CSA and UR certifications.

Frequently Asked Questions (FAQ)

Q: Can the FN3359-250-28 directly replace the FN258-250-40 in existing installations?

A: Functional substitution is possible based on matching current rating, filter type, and frequency range. However, termination style differences (terminal block vs. threaded post M10) require mechanical interface modification. Voltage rating differences must be evaluated against system specifications.

Q: What is the significance of the configuration difference (two-stage vs. three-stage)?

A: Configuration refers to the number of filtering stages. The three-stage design of the FN3359-250-28 provides additional attenuation compared to the two-stage FN258-250-40. This difference affects filtering performance but does not prevent substitution in applications where the enhanced filtering of the three-stage design is acceptable.

Q: Are the voltage ratings interchangeable?

A: The FN3359-250-28 has higher voltage ratings (300 V phase-to-ground, 520 V phase-to-phase) than the FN258-250-40 (277 V, 480 V). The substitute part can be used in applications rated for the original part's voltage levels. Applications operating at the substitute's higher voltage ratings require confirmation that the original design supports these levels.

Q: What are the termination implications?

A: The FN258-250-40 uses terminal block termination while the FN3359-250-28 uses threaded post (M10) termination. Substitution requires mechanical interface redesign to accommodate the different termination style. Wiring harnesses and connection points must be adapted accordingly.

Q: Why is the FN258-250-40 marked as Not For New Designs?

A: This status indicates the component is in mature or end-of-life phase. The FN3359-250-28, with active product status, represents the current generation equivalent and is recommended for new designs and ongoing support.

Q: Are both parts compliant with the same regulatory standards?

A: Both components are ROHS3 compliant and hold ENEC certification. The FN258-250-40 holds CSA and UR approvals while the FN3359-250-28 holds cURus approval. Application requirements determine which certification set is necessary.