Equivalent & Substitute Parts for Honeywell LSF1A4 Snap Action Switch

Part Overview

The Honeywell LSF1A4 is a snap action switch with SPDT (Single Pole Double Throw) configuration rated for 10A AC at 120V. This component features a side roller plunger actuator and chassis mount termination with plug-in connection style. The LSF1A4 is classified as obsolete, making equivalent substitute parts necessary for ongoing system maintenance and new design implementations. The switch operates in the temperature range of -12°C to 93°C and complies with RoHS standards.

Substiute Parts

LSF1A4

Honeywell Sensing and Productivity SolutionsIn Stock: 1109LSF1A4 Datasheet

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D4A-3107-VN

Omron Automation and SafetyIn Stock: 940D4A-3107-VN Datasheet

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D4A-3307-HN

Omron Automation and SafetyIn Stock: 908D4A-3307-HN Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LSF1A4 are identified based on functional and electrical compatibility within the snap action switch category. The primary substitution criteria are:

Circuit Configuration: Both substitute parts maintain SPDT (DB/DM) configuration, ensuring identical switching logic and contact arrangement.

Switch Function: On-Momentary operation is preserved across all substitute parts, maintaining consistent actuation behavior.

Actuator Type: Side roller plunger actuators are retained in all substitutes, ensuring mechanical compatibility with existing mechanical interfaces.

Mounting Type: Chassis mount configuration is maintained across all parts, allowing direct mechanical installation compatibility.

Current Rating (AC): All substitute parts are rated for 10A AC, matching the primary load-carrying specification of the original part.

Voltage Rating (AC): Substitute parts are rated for 125V AC, which exceeds the 120V AC requirement of the LSF1A4, providing operational compatibility.

RoHS Compliance: All substitute parts maintain RoHS compliance status, ensuring regulatory alignment.

The Omron D4A series parts (D4A-3107-VN and D4A-3307-HN) are active products that fulfill these core substitution criteria. Differences in termination style (screw terminal versus plug-in), ingress protection rating, and operating force represent design variations that must be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The LSF1A4 is classified as obsolete. The Omron D4A-3107-VN and D4A-3307-HN are both active products with current manufacturing support, inventory availability, and ongoing technical documentation.

Compliance and Certification: All three parts maintain RoHS compliance and MSL Level 1 rating, ensuring regulatory alignment for applications requiring these certifications.

Termination Interface: The LSF1A4 uses plug-in termination, while substitute parts employ screw terminal connections. Applications utilizing the original plug-in connector will require adapter solutions or circuit board redesign to accommodate screw terminal connections.

Voltage and Current Specifications: Both Omron substitutes exceed the AC voltage requirement (125V versus 120V) and maintain the 10A AC current rating. DC current ratings differ (6A for Omron versus 800mA for Honeywell), which is relevant only for DC-operated applications.

Operating Force Differential: The LSF1A4 specifies 2720gf operating force, while Omron substitutes specify 2000gf. This 720gf reduction may affect actuation feel and mechanical interface compatibility in applications with tight mechanical tolerances.

Temperature Range: The D4A-3107-VN supports -20°C to 100°C, exceeding the LSF1A4 range. The D4A-3307-HN supports -10°C to 80°C, which is narrower than the original part. Temperature range selection depends on specific application environment requirements.

Ingress Protection: Omron substitutes provide IP67 rating (dust tight, waterproof), offering enhanced environmental protection compared to the unspecified ingress protection of the LSF1A4.

Frequently Asked Questions (FAQ)

Q: Can the D4A-3107-VN or D4A-3307-HN directly replace the LSF1A4 without modifications?

A: Direct mechanical and electrical replacement is possible for AC applications operating at or below 120V with 10A current requirements. However, termination style differs (screw terminal versus plug-in), requiring connection interface modification. Operating force is reduced by 720gf, which may affect mechanical actuation characteristics in sensitive applications.

Q: What is the primary difference between the D4A-3107-VN and D4A-3307-HN?

A: Both parts share identical electrical ratings, circuit configuration, and mechanical specifications. The D4A-3307-HN includes a status indicator feature and operates within a narrower temperature range (-10°C to 80°C versus -20°C to 100°C for the D4A-3107-VN).

Q: Are the Omron substitutes suitable for DC applications?

A: The Omron D4A series is rated for 6A DC at 30V maximum. The original LSF1A4 is rated for 800mA DC at 115V. DC application compatibility depends on specific current and voltage requirements. Applications exceeding 6A DC or 30V DC cannot use these substitutes.

Q: What is the impact of the 720gf operating force reduction?

A: The LSF1A4 requires 2720gf to actuate, while Omron substitutes require 2000gf. This reduction may affect mechanical interface compatibility in applications with precise actuation force specifications or mechanical linkage designs optimized for the higher force requirement.

Q: Do the substitute parts maintain RoHS compliance?

A: Yes, both D4A-3107-VN and D4A-3307-HN are RoHS compliant with MSL Level 1 rating, matching the compliance status of the LSF1A4.

Q: What is the significance of the IP67 ingress protection rating on the Omron parts?

A: The Omron substitutes provide IP67 protection (dust tight and waterproof), while the LSF1A4 ingress protection is unspecified. This enhanced protection may provide additional environmental durability in applications exposed to moisture or particulate contamination.

Q: How do the pretravel and overtravel specifications compare?

A: Pretravel is nearly identical (0.100" for LSF1A4 versus 0.094" for Omron parts). Overtravel is slightly increased in Omron parts (0.190" versus 0.201"), representing a 0.011" difference that is negligible for most mechanical interfaces.