MRPR-3-42-48 Equivalent & Substitute Parts

Part Overview

The MRPR-3-42-48 is a glass body reed switch manufactured by Littelfuse Inc., configured as SPST-NO (Single Pole Single Throw - Normally Open) with a rated switching capacity of 1.1A AC and 1.5A DC at 140V AC / 200V DC. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system maintenance and new design implementations.

The MRPR-3-42-48 operates within a 42–48AT magnetic operate range and is designed for through-hole mounting with axial termination. Its 50W power rating and 0.75ms operate time make it suitable for low-power switching applications requiring reliable magnetic actuation.

Substiute Parts

MRPR-3-42-48

Littelfuse Inc.In Stock: 754MRPR-3-42-48 Datasheet

Current PartRFQ

MRPR-20-22-28

Littelfuse Inc.In Stock: 1944MRPR-20-22-28 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MRPR-3-42-48 is determined by the following critical parameters:

Circuit Configuration: Both the main part and substitute must maintain SPST-NO topology to preserve switching behavior in the application.

Switching Current & Voltage Ratings: The substitute must support the application's required current (1.1A AC / 1.5A DC minimum) and voltage (140V AC / 200V DC minimum). Higher ratings are acceptable; lower ratings are not.

Operate Range (Magnetic Sensitivity): The substitute's operate range determines the magnetic field strength required for actuation. The MRPR-3-42-48 operates at 42–48AT. Substitutes with different operate ranges may require magnetic field adjustment in the application.

Mounting & Termination: Through-hole mounting with axial termination must be preserved for PCB compatibility.

Physical Dimensions: Overall length and body diameter must be compatible with the application's mechanical constraints.

Operating Temperature Range: The substitute's temperature range must encompass the application's operating environment.

Compliance & Status: Active product status and current certifications (RoHS3, REACH) ensure long-term availability and regulatory compliance.

Parameter Comparison

Engineering Selection Recommendations

The MRPR-20-22-28 is a direct functional substitute for the MRPR-3-42-48 based on the following engineering criteria:

Electrical Compatibility: Both parts maintain identical switching current (1.1A AC / 1.5A DC) and power ratings (50W). The MRPR-20-22-28 provides higher voltage ratings (265V AC / 250V DC), making it suitable for applications operating at or below the MRPR-3-42-48 voltage specifications (140V AC / 200V DC).

Mechanical Compatibility: Both parts feature identical overall length (2.230"), body diameter (0.112"), through-hole mounting, and axial termination. The body length difference of 0.025" (0.63mm) is negligible for PCB-mounted applications.

Timing Characteristics: Operate time (0.75ms) and release time (0.3ms) are identical, ensuring equivalent switching performance.

Product Status & Availability: The MRPR-20-22-28 is actively manufactured by Littelfuse Inc., ensuring long-term availability and supply chain continuity. The MRPR-3-42-48 is obsolete.

Regulatory Compliance: Both parts are ROHS3 compliant. The MRPR-20-22-28 carries REACH Unaffected status, providing additional regulatory assurance.

Magnetic Operate Range Consideration: The MRPR-20-22-28 operates at 22–28AT, compared to the MRPR-3-42-48 at 42–48AT. This lower operate range means the substitute requires a weaker magnetic field for actuation. Applications using permanent magnets or electromagnets must provide sufficient magnetic field strength to trigger the MRPR-20-22-28 within its specified operate range.

Temperature Range: The MRPR-20-22-28 operates from −20°C to 125°C, compared to −40°C to 125°C for the MRPR-3-42-48. Applications requiring operation below −20°C must retain the original part or identify alternative substitutes with extended low-temperature ratings.

Frequently Asked Questions (FAQ)

Q: Can the MRPR-20-22-28 directly replace the MRPR-3-42-48 without circuit modifications?

A: The MRPR-20-22-28 is electrically and mechanically compatible for applications operating within −20°C to 125°C and providing magnetic field strength within the 22–28AT operate range. If the application's magnetic field is calibrated for the MRPR-3-42-48 (42–48AT), the magnetic source may require adjustment to reliably trigger the MRPR-20-22-28. No circuit modifications are required if magnetic field strength is adequate.

Q: What is the significance of the operate range difference (42–48AT vs. 22–28AT)?

A: The operate range specifies the magnetic field strength (in Ampere-Turns) required to close the reed switch contacts. The MRPR-20-22-28 requires a weaker magnetic field than the MRPR-3-42-48. If the application uses a fixed magnetic source (permanent magnet or electromagnet), the magnetic field strength must be verified to fall within the substitute's 22–28AT range. If the field is too weak, the switch will not actuate; if too strong, the switch may remain closed when it should open.

Q: Are there any temperature-related limitations when substituting?

A: Yes. The MRPR-20-22-28 operates from −20°C to 125°C, while the MRPR-3-42-48 operates from −40°C to 125°C. If the application requires operation below −20°C, the MRPR-20-22-28 is not suitable. Confirm the application's minimum operating temperature before substitution.

Q: How do the voltage ratings compare, and does the higher rating of the MRPR-20-22-28 affect compatibility?

A: The MRPR-20-22-28 is rated for 265V AC and 250V DC, compared to 140V AC and 200V DC for the MRPR-3-42-48. Higher voltage ratings indicate greater dielectric strength and are acceptable for applications operating at or below the original part's voltage specifications. No derating or circuit modification is required.

Q: Are both parts available in the same packaging?

A: The MRPR-3-42-48 is available in bulk packaging with 737 pieces in stock (obsolete status). The MRPR-20-22-28 is available in bulk packaging with 1,868 pieces in stock (active status). Both use identical through-hole axial termination suitable for standard PCB assembly processes.

Q: What compliance certifications apply to the MRPR-20-22-28?

A: The MRPR-20-22-28 is ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic components in most jurisdictions.