LF-340 Line Filter Equivalent & Substitute Parts

Part Overview

The LF-340 is a three-phase delta EMC/EMI line filter manufactured by KEMET, rated for 250V DC/AC at 40A with two-stage configuration and chassis mount installation. This component is classified as Last Time Buy, indicating discontinued production status. Identification of equivalent substitute parts is necessary to ensure continued availability for system integration and maintenance applications requiring three-phase line filtering in general-purpose installations.

Substiute Parts

LF-340

KEMETIn Stock: 860LF-340 Datasheet

Current PartRFQ

GTX-3400-Y103

KEMETIn Stock: 869GTX-3400-Y103 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LF-340 is determined by the following critical parameters that must align with the original component specification:

Mandatory Matching Parameters:

• Filter Type: Three Phase (Delta) configuration
• Configuration: Two Stage topology
• Current Rating: 40A
• Mounting Type: Chassis Mount
• RoHS Compliance: ROHS3 Compliant

Voltage Consideration: The LF-340 operates at 250V DC/AC. Substitute parts must maintain voltage ratings equal to or exceeding the original specification to ensure safe operation within the target application circuit.

Termination Compatibility: The original LF-340 uses Threaded Post (M4) termination. Substitute parts may employ alternative termination styles (such as Terminal Block) provided the mechanical and electrical interface is compatible with the installation environment.

The GTX-3400-Y103 qualifies as a substitute based on matching filter type, configuration, current rating, and mounting type, with elevated voltage rating (500V DC) providing margin above the original 250V specification.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: GTX-3400-Y103

The GTX-3400-Y103 is the manufacturer-recommended substitute for the LF-340. Selection is based on the following engineering criteria:

1. Functional Equivalence: Both components are three-phase delta EMC/EMI line filters with two-stage configuration and 40A current rating, suitable for chassis mount applications.

2. Voltage Rating: The GTX-3400-Y103 is rated for 500V DC, which exceeds the original 250V DC specification. This elevated rating provides operational margin and is compatible with circuits designed for 250V operation.

3. Product Availability: The LF-340 is Last Time Buy status with limited inventory (778 pcs). The GTX-3400-Y103 is Active status with current production (794 pcs available), ensuring long-term supply continuity.

4. Compliance Status: Both components are ROHS3 compliant. The GTX-3400-Y103 carries cUL and UL approvals, providing additional regulatory certification.

5. Operating Temperature: The GTX-3400-Y103 operates across -25°C to 55°C, extending the lower and upper temperature limits compared to the LF-340 (-20°C to 45°C).

Installation Consideration: The termination style differs (Threaded Post M4 versus Terminal Block). Mechanical interface compatibility must be verified for the specific installation environment before final selection.

Frequently Asked Questions (FAQ)

Q: Can the GTX-3400-Y103 directly replace the LF-340 in existing installations?

A: The GTX-3400-Y103 is functionally equivalent in filter type, configuration, current rating, and mounting type. However, the termination style differs (Terminal Block versus Threaded Post M4). Direct mechanical replacement requires verification that the installation supports Terminal Block termination or that an appropriate adapter interface is available.

Q: Why is the GTX-3400-Y103 rated for 500V DC when the LF-340 is 250V?

A: The higher voltage rating of the GTX-3400-Y103 (500V DC) does not prevent its use in 250V applications. Components rated for higher voltages are compatible with lower-voltage circuits. The elevated rating provides operational margin and may indicate different internal component specifications within the filter assembly.

Q: Are there differences in filtering performance between the LF-340 and GTX-3400-Y103?

A: Both components share identical filter type (three-phase delta), configuration (two-stage), and current rating (40A). Inductance values are not specified in the provided data for either component. Performance differences, if any, would be determined by internal component specifications not included in this reference.

Q: What is the significance of the LF-340 being Last Time Buy?

A: Last Time Buy status indicates that KEMET has discontinued production of the LF-340. Existing inventory (778 pcs) represents the final available stock. The GTX-3400-Y103, classified as Active, is the recommended substitute for future procurement to ensure continued supply availability.

Q: Does the GTX-3400-Y103 have better regulatory approvals?

A: The GTX-3400-Y103 carries cUL and UL certifications, while approval agencies are not specified for the LF-340. Both components are ROHS3 compliant. The additional certifications on the GTX-3400-Y103 may be relevant for applications requiring specific regulatory compliance documentation.

Q: Can the operating temperature range difference affect substitution?

A: The GTX-3400-Y103 operates across -25°C to 55°C, compared to the LF-340 at -20°C to 45°C. The substitute has a wider operating range, making it suitable for applications with more extreme temperature requirements. For applications within the original -20°C to 45°C range, both components are compatible.