Honeywell 1SM1 Snap Action Switch Equivalent & Substitute Parts

Part Overview

The Honeywell 1SM1 is a snap action SPDT (Single Pole Double Throw) 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 operation. The part is currently active in production with 698 units in stock.

Equivalent and substitute parts are necessary when the primary part becomes unavailable, when design requirements shift toward different electrical ratings or environmental protection levels, or when alternative manufacturers' components meet the same functional specifications within acceptable parameter tolerances.

Substiute Parts

1SM1

Honeywell Sensing and Productivity SolutionsIn Stock: 7651SM1 Datasheet

Current PartRFQ

DB1C-A1AA

Hirose Electric Co LtdIn Stock: 919DB1C-A1AA Datasheet

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DB2CA1AA

ZF ElectronicsIn Stock: 20959DB2CA1AA Datasheet

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DC1C-A1AA

ZF ElectronicsIn Stock: 21897DC1C-A1AA Datasheet

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DC2C-A1AA

ZF ElectronicsIn Stock: 1173DC2C-A1AA Datasheet

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DC3C-A1AA

Hirose Electric Co LtdIn Stock: 1171DC3C-A1AA Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the Honeywell 1SM1 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Circuit configuration (SPDT required)
• Switch function (On-Momentary operation)
• Actuator type (Round pin plunger)
• Mounting type (Chassis mount)
• Termination style (Solder lug)
• Operating position (0.330" / 8.4mm)

Electrical Rating Considerations: Substitute parts must maintain compatibility with the application's voltage and current requirements. The 1SM1 operates at 5A AC/DC with 250V AC and 30V DC ratings. Substitutes with equal or higher current ratings and voltage ratings are electrically compatible. Substitutes with lower ratings require application-specific verification.

Environmental and Compliance Factors: Ingress protection, operating temperature range, mechanical life cycles, and regulatory compliance (RoHS, REACH, ECCN) influence substitution suitability based on end-use requirements.

Parameter Comparison

Engineering Selection Recommendations

Active Production Substitutes:

The ZF Electronics DC1C-A1AA and DC2C-A1AA are active production parts with ROHS3 compliance and enhanced ingress protection (IP67). These parts maintain the required SPDT circuit, on-momentary function, round pin plunger actuator, chassis mount configuration, and solder lug termination. The DC1C-A1AA matches the 5A AC current rating of the 1SM1 and provides 48V DC capability, exceeding the 30V DC requirement. The DC2C-A1AA provides 10A AC capacity with IP67 protection for applications requiring higher current handling or enhanced environmental sealing.

The ZF Electronics DB2CA1AA is an active production part with 10A AC rating and IP50 ingress protection, suitable for applications requiring higher current capacity with moderate environmental protection.

Obsolete Status Substitutes:

The Hirose Electric DB1C-A1AA and DC3C-A1AA are marked as obsolete. These parts should not be selected for new designs or long-term production applications due to discontinued manufacturing status and unavailable technical specifications.

Compliance Considerations:

The 1SM1 is RoHS non-compliant. Applications requiring RoHS3 compliance must transition to DC1C-A1AA, DC2C-A1AA, or DB2CA1AA. All substitute parts share the same ECCN (EAR99) and HTSUS classification as the primary part.

Frequently Asked Questions (FAQ)

Q: Can the ZF Electronics DC1C-A1AA directly replace the Honeywell 1SM1?

A: The DC1C-A1AA maintains electrical and mechanical compatibility through matching SPDT circuit configuration, on-momentary function, round pin plunger actuator, 0.330" operating position, chassis mount, and solder lug termination. The DC1C-A1AA provides 5A AC at 125V and 1A DC at 48V, which covers the 1SM1's 5A AC at 250V requirement within the DC voltage range. The operating temperature range of the DC1C-A1AA (-40°C to 120°C) is narrower than the 1SM1 (-55°C to 125°C). The DC1C-A1AA includes IP67 ingress protection and ROHS3 compliance, providing enhanced environmental sealing and regulatory compliance compared to the 1SM1.

Q: What is the difference between the DC1C-A1AA and DC2C-A1AA?

A: Both parts are ZF Electronics active production switches with identical mechanical specifications, operating position, and ingress protection (IP67). The primary difference is current rating: the DC1C-A1AA is rated for 5A AC and 1A DC, while the DC2C-A1AA is rated for 10A AC. The DC2C-A1AA has a higher operating force (340gf versus 204gf), indicating a stiffer actuator mechanism. Selection between these parts depends on the application's current requirements.

Q: Why are DB1C-A1AA and DC3C-A1AA listed as substitutes if they are obsolete?

A: These parts are included in the substitute list based on the provided input data. However, obsolete status indicates discontinued manufacturing. These parts should not be selected for new designs or applications requiring long-term component availability. Active production alternatives (DC1C-A1AA, DC2C-A1AA, DB2CA1AA) are recommended instead.

Q: Does the 1SM1 meet RoHS requirements?

A: The 1SM1 is RoHS non-compliant. Applications requiring RoHS3 compliance must use DC1C-A1AA, DC2C-A1AA, or DB2CA1AA, all of which are ROHS3 compliant.

Q: What is the significance of the IP67 rating on the DC1C-A1AA and DC2C-A1AA?

A: IP67 classification indicates dust-tight and waterproof protection. The 1SM1 does not specify an ingress protection rating. Applications requiring environmental sealing against dust and moisture ingress benefit from the IP67-rated substitutes. The DB2CA1AA provides IP50 protection (dust protected but not waterproof).

Q: Are there current rating limitations when substituting the 1SM1?

A: The 1SM1 is rated for 5A AC/DC. The DC1C-A1AA provides 5A AC and 1A DC, matching the AC rating but limiting DC applications to 1A. The DC2C-A1AA and DB2CA1AA provide 10A AC, exceeding the 1SM1's AC capacity. Applications requiring the full 5A DC capability of the 1SM1 must verify that substitute parts meet this requirement or operate within the substitute's DC current limit.

Q: What mechanical life cycle differences exist between the 1SM1 and its substitutes?

A: The 1SM1 specifies 80,000 mechanical cycles. The DB2CA1AA provides 10,000,000 cycles, and the DC1C-A1AA and DC2C-A1AA provide 1,000,000 cycles. Applications with high cycle count requirements benefit from these substitutes. The DB1C-A1AA and DC3C-A1AA do not specify mechanical life data.

Q: Can the 1SM1 be used in applications requiring 250V AC operation with substitute parts?

A: The 1SM1 is rated for 250V AC. The ZF Electronics substitutes (DC1C-A1AA, DC2C-A1AA, DB2CA1AA) are rated for 125V AC maximum. These substitutes are not suitable for 250V AC applications. The Hirose Electric substitutes (DB1C-A1AA, DC3C-A1AA) do not specify voltage ratings. Applications requiring 250V AC operation must retain the 1SM1 or identify alternative parts with matching voltage specifications.