Honeywell 21SM144 SPDT Snap Action Switch - Equivalent & Substitute Parts

Part Overview

The Honeywell 21SM144 is an SPDT (Single Pole Double Throw) snap action switch rated for 5A at 250V AC and 30V DC. This chassis-mount switch features a round pin plunger actuator with solder lug termination and is designed for on-momentary switching applications. The part is currently active in production with 1060 units in stock inventory.

Substitute parts are identified when equivalent electrical ratings, mechanical configurations, and circuit topologies are available from alternative manufacturers. Substitution becomes necessary when primary part availability is limited, lead times are extended, or design flexibility permits alternative actuator force characteristics within acceptable operating parameters.

Substiute Parts

21SM144

Honeywell Sensing and Productivity SolutionsIn Stock: 112521SM144 Datasheet

Current PartRFQ

MS0850500F060S1A

E-SwitchIn Stock: 1035MS0850500F060S1A Datasheet

SimilarRFQ

MS0850500F080S1A

E-SwitchIn Stock: 1289MS0850500F080S1A Datasheet

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MS0850500F250S1A

E-SwitchIn Stock: 1435MS0850500F250S1A Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the Honeywell 21SM144 are identified based on strict electrical and mechanical parameter matching:

Mandatory Matching Parameters:

• Circuit: SPDT (Single Pole Double Throw)
• Switch Function: On-Momentary
• Current Rating: 5A minimum
• Actuator Type: Round Pin Plunger
• Mounting Type: Chassis Mount
• Termination Style: Solder Lug

Voltage Rating Considerations: The Honeywell 21SM144 is rated for 250V AC and 30V DC. Substitute parts from E-Switch (MS series) are rated for 125V AC maximum. This represents a voltage derating and restricts substitution to applications operating at or below 125V AC. DC voltage rating information is not provided for E-Switch alternatives; therefore, substitution for DC applications is not supported.

Actuator Force Variations: The identified E-Switch substitutes (MS0850500F060S1A, MS0850500F080S1A, MS0850500F250S1A) feature different operating forces (60gf, 80gf, and 250gf respectively) compared to the Honeywell 21SM144 (85gf). These force variations are permitted substitutions when application requirements allow for different actuation characteristics.

Environmental and Compliance Considerations: The Honeywell 21SM144 operates across -55°C to 125°C. E-Switch alternatives operate across -25°C to 85°C, representing a narrower temperature range. Substitution is valid only for applications within the -25°C to 85°C envelope.

Parameter Comparison

Engineering Selection Recommendations

Voltage Derating Requirement: E-Switch MS series substitutes are rated for 125V AC maximum, compared to the Honeywell 21SM144 rated for 250V AC. Selection of E-Switch alternatives is restricted to applications operating at 125V AC or below. Applications requiring 250V AC operation must use the Honeywell 21SM144 or equivalent 250V-rated alternatives.

DC Application Limitation: DC voltage ratings are not specified for E-Switch MS0850500 series parts. The Honeywell 21SM144 is rated for 30V DC. Substitution for DC applications cannot be confirmed without DC rating data for E-Switch alternatives.

Temperature Range Consideration: The Honeywell 21SM144 operates across -55°C to 125°C. E-Switch alternatives operate across -25°C to 85°C. Applications requiring operation below -25°C or above 85°C must use the Honeywell 21SM144.

Mechanical Life Advantage: E-Switch MS series parts specify 1,000,000 mechanical cycles compared to 80,000 cycles for the Honeywell 21SM144. This represents a 12.5x improvement in mechanical durability for E-Switch alternatives.

Regulatory Compliance: All parts are RoHS compliant. Honeywell 21SM144 is RoHS Compliant. E-Switch alternatives are ROHS3 Compliant. Both compliance levels are acceptable for equivalent regulatory purposes.

Actuator Force Selection: Three E-Switch alternatives provide different operating forces:

• MS0850500F060S1A: 60gf (lighter actuation than Honeywell 21SM144)
• MS0850500F080S1A: 80gf (closest to Honeywell 21SM144 at 85gf)
• MS0850500F250S1A: 250gf (significantly heavier actuation)

Selection depends on application-specific actuation requirements.

Frequently Asked Questions (FAQ)

Q: Can E-Switch MS0850500 series parts directly replace the Honeywell 21SM144 in all applications?

A: No. E-Switch alternatives are rated for 125V AC maximum, while the Honeywell 21SM144 is rated for 250V AC. Substitution is valid only for applications operating at 125V AC or below. Additionally, E-Switch parts operate across -25°C to 85°C, compared to the Honeywell part's -55°C to 125°C range. Substitution is restricted to applications within the narrower temperature envelope.

Q: What is the difference between the three E-Switch substitute part numbers?

A: The three E-Switch alternatives (MS0850500F060S1A, MS0850500F080S1A, MS0850500F250S1A) differ only in operating force and release force characteristics. All three share identical electrical ratings (5A, 125V AC), mechanical configuration (SPDT, chassis mount, solder lug), and environmental specifications. The suffix designations (F060, F080, F250) indicate operating force in grams-force (60gf, 80gf, 250gf respectively).

Q: Are E-Switch parts suitable for DC applications?

A: DC voltage ratings are not provided in the technical data for E-Switch MS0850500 series parts. The Honeywell 21SM144 is rated for 30V DC. Substitution for DC applications cannot be confirmed. Applications requiring DC operation should use the Honeywell 21SM144 or request DC rating specifications from E-Switch.

Q: Which E-Switch part is closest to the Honeywell 21SM144 in terms of operating force?

A: The MS0850500F080S1A features an 80gf operating force, which is closest to the Honeywell 21SM144's 85gf operating force. This part represents the most direct mechanical substitute when actuator force characteristics are critical to application performance.

Q: What is the mechanical life advantage of E-Switch alternatives?

A: E-Switch MS0850500 series parts specify 1,000,000 mechanical cycles, compared to 80,000 cycles for the Honeywell 21SM144. This represents a 12.5-fold improvement in cycle life. Applications requiring extended operational life may benefit from E-Switch alternatives, provided voltage and temperature requirements are met.

Q: Are all parts RoHS compliant?

A: Yes. The Honeywell 21SM144 is RoHS Compliant. All three E-Switch alternatives are ROHS3 Compliant. Both compliance designations satisfy RoHS regulatory requirements.

Q: What inventory levels are available?

A: Honeywell 21SM144: 1060 units. E-Switch MS0850500F060S1A: 997 units. E-Switch MS0850500F080S1A: 1250 units. E-Switch MS0850500F250S1A: 1404 units. All parts are listed as new original stock.

Q: Can these switches be used interchangeably in existing designs?

A: Mechanical and electrical interchangeability depends on application-specific requirements. All parts share identical circuit topology (SPDT), current rating (5A), actuator type (round pin plunger), mounting method (chassis mount), and termination style (solder lug). However, voltage rating differences (250V vs. 125V AC), temperature range differences (-55°C to 125°C vs. -25°C to 85°C), and operating force variations must be evaluated against design specifications before substitution.