MT-4R-A28 Equivalent & Substitute Parts Reference

Part Overview

The MT-4R-A28 is a snap action SPDT (Single Pole Double Throw) switch manufactured by Honeywell Sensing and Productivity Solutions. This chassis-mounted switch features a round pin plunger actuator with screw terminal connections, rated for 10A at 125V AC/DC operation. The product is currently active in production with 915 units in stock.

Substitute parts are identified when equivalent functional performance can be achieved within the allowed electrical and mechanical parameter ranges for snap action SPDT switches. Substitution becomes necessary when the primary part is unavailable, when packaging requirements differ, or when specific operational characteristics better suit application requirements.

Substiute Parts

MT-4R-A28

Honeywell Sensing and Productivity SolutionsIn Stock: 988MT-4R-A28 Datasheet

Current PartRFQ

TZ-1G

Omron Automation and SafetyIn Stock: 1058TZ-1G Datasheet

SimilarRFQ

Z-01HD55-B

Omron Automation and SafetyIn Stock: 1035Z-01HD55-B Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MT-4R-A28 are identified based on the following critical parameters that define functional equivalence:

Primary Substitution Criteria:

• Circuit configuration: SPDT (Single Pole Double Throw)
• Switch function: On-Mom (On-Momentary)
• Actuator type: Round (Pin Plunger)
• Mounting type: Chassis Mount
• Termination style: Screw Terminal
• Voltage rating: 125V AC minimum

Secondary Compatibility Parameters:

• Current rating tolerance (may vary based on application requirements)
• Operating temperature range (must encompass application operating conditions)
• Mechanical characteristics (operating force, travel distances)
• Packaging format (Bulk or Tray)
• Compliance certifications (RoHS, REACH status)

The identified substitute parts TZ-1G and Z-01HD55-B share the core SPDT snap action architecture with identical actuator and mounting configurations. However, each substitute exhibits different current ratings and operational characteristics that define their specific application suitability.

Parameter Comparison

Engineering Selection Recommendations

MT-4R-A28 (Primary Selection)

The MT-4R-A28 remains the primary component choice for applications requiring 10A switching capacity at 125V AC/DC. This part is actively produced by Honeywell with 915 units in current inventory. The component meets RoHS compliance requirements and carries MSL Level 1 rating, indicating no moisture sensitivity constraints for storage and handling.

TZ-1G (Omron Alternative)

The TZ-1G substitute is suitable for applications where current requirements do not exceed 1A at 125V AC or 30V DC. This Omron part shares identical operating position (0.625") and mounting configuration with the main part. The TZ-1G offers extended temperature operation (-65°C to 400°C) and documented electrical life (50,000 cycles) and mechanical life (100,000 cycles). ROHS3 compliance and Tray packaging differentiate this option. Selection of TZ-1G is appropriate when lower current loads permit downsizing and extended temperature performance is required.

Z-01HD55-B (Omron Alternative)

The Z-01HD55-B substitute is applicable for low-current applications limited to 100mA at 125V AC or 30V DC. This part features IP62 ingress protection and significantly higher mechanical life (20,000,000 cycles) with extended electrical life (500,000 cycles). Operating position differs at 0.846" (21.5mm), requiring mechanical accommodation verification. Z-01HD55-B selection is appropriate for sealed enclosure applications with high cycle count requirements and minimal current demands.

All three parts maintain active product status, RoHS compliance, and unlimited moisture sensitivity ratings, supporting direct substitution within their respective electrical parameter boundaries.

Frequently Asked Questions (FAQ)

Q: Can TZ-1G replace MT-4R-A28 in all applications?

A: No. TZ-1G is rated for maximum 1A current, compared to MT-4R-A28's 10A rating. Substitution is valid only for applications where actual circuit current does not exceed 1A. DC voltage rating is also limited to 30V on TZ-1G versus 125V on the main part.

Q: What is the primary difference between TZ-1G and Z-01HD55-B?

A: Current rating is the primary distinction. TZ-1G handles 1A maximum, while Z-01HD55-B is limited to 100mA. Z-01HD55-B provides IP62 sealing and significantly higher cycle life (20,000,000 mechanical cycles). Operating position differs: TZ-1G matches MT-4R-A28 at 0.625", while Z-01HD55-B operates at 0.846".

Q: Does packaging format affect electrical performance?

A: No. Packaging (Bulk versus Tray) affects logistics, storage, and handling only. Electrical and mechanical specifications remain identical regardless of packaging format.

Q: Are all three parts RoHS compliant?

A: Yes. MT-4R-A28 and Z-01HD55-B carry RoHS Compliant certification. TZ-1G carries ROHS3 Compliant certification. Both certifications satisfy RoHS directive requirements.

Q: Can Z-01HD55-B be used in place of MT-4R-A28 for a 10A circuit?

A: No. Z-01HD55-B maximum current rating is 100mA. Using this part in a 10A circuit will result in component failure and circuit malfunction.

Q: What is the operating temperature consideration for substitution?

A: MT-4R-A28 operates -55°C to 82°C. TZ-1G extends to -65°C to 400°C. Z-01HD55-B operates -15°C to 80°C. Verify application temperature requirements fall within the selected part's operating range.

Q: Do all parts use identical mounting and termination?

A: Yes. All three parts are chassis-mounted with screw terminal connections and round pin plunger actuators. Mechanical mounting compatibility is confirmed across all options.