MRPR-3-27-33 Equivalent & Substitute Parts

Part Overview

The MRPR-3-27-33 is a glass body reed switch manufactured by Littelfuse Inc., configured as a single-pole single-throw normally open (SPST-NO) device. This component is designed for applications requiring low-power switching with an operating range of 27 to 33 ampere-turns (AT) and rated for 50W power dissipation. The part is classified as obsolete, making identification of suitable substitute components necessary for ongoing system support and new design implementations.

Substiute Parts

MRPR-3-27-33

Littelfuse Inc.In Stock: 838MRPR-3-27-33 Datasheet

Current PartRFQ

MRPR-20-27-33

Littelfuse Inc.In Stock: 10594MRPR-20-27-33 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The MRPR-20-27-33 qualifies as a direct substitute for the MRPR-3-27-33 based on the following critical parameters:

Matching Parameters:

• Circuit configuration: SPST-NO
• Operate range: 27 ~ 33 AT
• Current switching capability: 1.1 A (AC), 1.5 A (DC)
• Power rating: 50 W
• Operate and release times: 0.75 ms and 0.3 ms
• Mounting type: Through Hole
• Termination style: Axial
• Overall length: 2.230" (56.64 mm)
• Capacitance: 0.2 pF
• Current carry capacity: 3 A (DC)
• RoHS compliance: ROHS3 Compliant
• MSL rating: 1 (Unlimited)

Distinguishing Parameters:

• Voltage switching capability (AC/DC)
• Body dimensions (minor variation)
• Operating temperature range
• Product status (Active vs. Obsolete)

The MRPR-20-27-33 maintains functional equivalence in switching characteristics while offering enhanced voltage ratings and active product status.

Parameter Comparison

Engineering Selection Recommendations

The MRPR-20-27-33 is the appropriate substitute for the obsolete MRPR-3-27-33. Both components maintain identical switching characteristics, power ratings, and response times. The MRPR-20-27-33 offers the following advantages:

• Active product status ensures ongoing availability and manufacturing support
• Enhanced voltage switching ratings (265 V AC, 250 V DC) provide margin for applications operating at or near the original 140 V AC specification
• ROHS3 compliance and unlimited MSL rating maintain regulatory and environmental standards
• Through-hole mounting and axial termination preserve mechanical compatibility with existing PCB designs

The minor variation in body length (0.025" difference) and operating temperature lower limit (-20°C vs. -40°C) must be evaluated against specific application requirements. For applications requiring the full -40°C lower temperature bound, alternative solutions should be considered.

Frequently Asked Questions (FAQ)

Q: Can the MRPR-20-27-33 directly replace the MRPR-3-27-33 in existing designs?

A: Yes, for applications operating within the MRPR-20-27-33 temperature range (-20°C to 125°C) and voltage specifications (265 V AC, 250 V DC). The identical switching current, power rating, operate range, and response times ensure functional compatibility. PCB layout modifications are not required due to matching overall length and axial termination.

Q: What are the key differences between these two parts?

A: The primary differences are product status (Active vs. Obsolete), voltage ratings (MRPR-20-27-33 rated higher), operating temperature lower limit (MRPR-20-27-33 limited to -20°C), and body diameter tolerance (0.025" variation). Switching performance parameters are identical.

Q: Is the MRPR-20-27-33 suitable for applications originally designed for 140 V AC operation?

A: Yes. The MRPR-20-27-33 is rated for 265 V AC, which exceeds the original 140 V AC requirement. This provides additional voltage margin and is suitable for the original application specification.

Q: Are there packaging differences between these parts?

A: The MRPR-3-27-33 is listed with "-" packaging designation, while the MRPR-20-27-33 is supplied in Bulk packaging. Both maintain identical through-hole mounting and axial termination characteristics.

Q: What should be verified before implementing the MRPR-20-27-33 as a replacement?

A: Confirm that the application operating temperature range does not require operation below -20°C. Verify that the 0.025" body length variation does not impact mechanical clearances in the assembly. Confirm voltage specifications are within the MRPR-20-27-33 ratings.