Honeywell LSD8A Snap Action Switch - Equivalent & Substitute Parts

Part Overview

The Honeywell LSD8A is a snap action SPDT (Single Pole Double Throw) switch with chassis mount configuration, rated for 10A AC at 120V and 800mA DC at 115V. This component features a roller plunger actuator with status indicator and is classified as obsolete. Due to its obsolete product status, equivalent substitute parts from active manufacturers are necessary to maintain design continuity and ensure long-term component availability for new production runs and field replacements.

Substiute Parts

LSD8A

Honeywell Sensing and Productivity SolutionsIn Stock: 944LSD8A Datasheet

Current PartRFQ

D4A-1310N

Omron Automation and SafetyIn Stock: 961D4A-1310N Datasheet

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D4A-3110N

Omron Automation and SafetyIn Stock: 860D4A-3110N Datasheet

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D4A-3310N

Omron Automation and SafetyIn Stock: 943D4A-3310N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete Honeywell LSD8A is based on the following critical parameters that must be maintained for functional equivalence:

Core Electrical Parameters:

• Circuit configuration: SPDT (DB/DM) topology
• Switch function: On-Momentary operation
• Current rating: Minimum 10A AC capability
• Voltage rating: AC rating of 125V or higher (exceeds original 120V requirement)

Mechanical Parameters:

• Actuator type: Roller plunger
• Mounting type: Chassis mount
• Pretravel and differential travel within 0.016" (0.4mm) tolerance band
• Overtravel within acceptable range (0.190" to 0.201")

Compliance Parameters:

• RoHS compliance maintained
• MSL rating 1 (Unlimited)
• Active product status for ongoing availability

The three Omron D4A series parts (D4A-1310N, D4A-3110N, D4A-3310N) meet these substitution criteria. All three maintain SPDT configuration, 10A AC rating, roller plunger actuation, and chassis mount design. The D4A series offers enhanced specifications including IP67 ingress protection, screw terminal termination, and extended electrical life ratings (1,000,000 cycles).

Parameter Comparison

Engineering Selection Recommendations

Primary Selection Criteria:

All three Omron D4A series substitutes are functionally equivalent to the Honeywell LSD8A based on core electrical and mechanical parameters. Selection among the three options depends on specific application requirements:

D4A-1310N Selection: Use when operating temperature range of -10°C to 80°C is acceptable and status indicator is required. This part provides the baseline D4A series functionality with active product status and full RoHS compliance.

D4A-3110N Selection: Use when extended operating temperature range is required. This part operates from -20°C to 100°C, providing the widest temperature envelope among the three substitutes. Suitable for applications with extreme environmental conditions. Status indicator feature is not included.

D4A-3310N Selection: Use when operating temperature range of -10°C to 80°C is acceptable and status indicator functionality is required. This part combines the temperature range of D4A-1310N with the status indicator feature, matching the original LSD8A indicator capability.

Termination Consideration: All Omron substitutes feature screw terminal termination, differing from the original plug-in termination of the LSD8A. Circuit board or connector modifications may be required during integration.

Compliance Assurance: All substitute parts maintain RoHS compliance and MSL rating 1 (Unlimited), ensuring regulatory and environmental compatibility with the original specification.

Frequently Asked Questions (FAQ)

Q: Can the Omron D4A series parts directly replace the Honeywell LSD8A without circuit modifications?

A: The D4A series maintains electrical and mechanical equivalence in circuit function and actuator response. However, termination style differs: the LSD8A uses plug-in termination while D4A parts use screw terminals. Connector or circuit board modifications are required for physical integration.

Q: What is the primary difference between D4A-1310N, D4A-3110N, and D4A-3310N?

A: The three parts differ in operating temperature range and status indicator presence. D4A-3110N offers the widest temperature range (-20°C to 100°C) without status indicator. D4A-1310N and D4A-3310N both operate from -10°C to 80°C; D4A-3310N includes status indicator while D4A-1310N does not.

Q: Are the mechanical dimensions and actuator response identical between LSD8A and D4A substitutes?

A: Operating force is nearly identical (1814gf vs. 1800gf). Pretravel differs slightly (0.071" vs. 0.063"), and overtravel is marginally higher (0.190" vs. 0.201"). Differential travel is identical at 0.016" (0.4mm). These variations are within acceptable mechanical tolerance for SPDT snap action switch applications.

Q: What is the significance of the IP67 rating on D4A parts compared to the LSD8A?

A: The D4A series provides IP67 ingress protection (dust tight and waterproof), which is not specified for the LSD8A. This enhanced protection is a design improvement in the substitute parts and does not create incompatibility; it provides additional environmental protection in applications where moisture or dust exposure is a concern.

Q: Does the higher DC current rating (6A vs. 800mA) on D4A parts affect compatibility?

A: The D4A series DC rating of 6A exceeds the LSD8A specification of 800mA. This represents improved capability and does not create incompatibility. Applications designed for 800mA DC operation will function correctly with the higher-rated D4A parts.

Q: Are all three D4A substitutes in active production status?

A: Yes. All three parts (D4A-1310N, D4A-3110N, D4A-3310N) are classified as active products from Omron Automation and Safety, ensuring long-term availability and supply chain continuity compared to the obsolete LSD8A.

Q: What inventory levels are available for these substitute parts?

A: Current inventory includes D4A-1310N (945 pcs), D4A-3110N (797 pcs), and D4A-3310N (889 pcs) in new original condition, providing adequate stock for production and replacement requirements.