Littelfuse 551844 Equivalent & Substitute Parts Reference

Part Overview

The Littelfuse/Commercial Vehicle Products 551844 is a panel mount toggle switch with a Single-Pole Double-Throw (SPDT) configuration, rated for 15A at 24V DC, featuring a momentary-off-momentary (Mom-Off-Mom) switch function. It has a non-illuminated, standard round brass, chrome-plated actuator with screw terminal connections, designed for an 11.90mm circular panel cutout and 15/32-32 bushing thread. The 551844 is ROHS3 compliant and currently has an obsolete product status. Sourcing equivalent or substitute parts is essential due to the part’s obsolescence, ensuring continued compatibility in maintenance, repair, and production applications.

Substiute Parts

551844

Littelfuse/Commercial Vehicle ProductsIn Stock: 978551844 Datasheet

Current PartRFQ

55021

Littelfuse/Commercial Vehicle ProductsIn Stock: 75655021 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution is determined strictly by matching electrical function, mounting type, current and voltage ratings, mechanical actuator characteristics, panel compatibility, and regulatory status. The permitted substitute, Littelfuse/Commercial Vehicle Products 55021, aligns with the 551844 on these critical parameters: SPDT circuit, Mom-Off-Mom function, 15A (DC) current rating, 24V DC voltage rating, panel mount style, 11.90mm panel cutout, 15/32-32 bushing thread, screw terminal termination, non-illuminated standard round actuator, and compliance with ROHS3 and REACH requirements. Only explicitly listed specifications are used for equivalence.

Parameter Comparison

Engineering Selection Recommendations

As the Littelfuse 551844 is obsolete, the Littelfuse 55021 is listed as a manufacturer-authorized substitute with active status and in-stock availability. Both part numbers conform to ROHS3 and REACH requirements and share identical electrical and most mechanical parameters, with only actuator length and plating variations within the provided data.

Frequently Asked Questions (FAQ)

Q1: What makes Littelfuse 55021 a valid substitute for Littelfuse 551844?
A1: The Littelfuse 55021 provides identical SPDT functionality, current rating, voltage rating, switch function, termination style, panel cutout, and compliance status as the 551844.

Q2: Are there package or mounting differences to consider?
A2: Both models utilize a panel mount style, circular 11.90mm panel cutout, and identical bushing threading (15/32-32), ensuring drop-in mechanical compatibility.

Q3: Does the actuator material or length affect substitution?
A3: The actuator material is different (brass, chrome plated vs. brass, nickel plated) and actuator length varies. All other critical electrical and mechanical fit parameters are aligned within the given data.

Q4: Are these substitute parts RoHS or REACH compliant?
A4: Both the 551844 and the 55021 are ROHS3 compliant and REACH unaffected, which supports compliance-driven selection.

Q5: Is the electrical function and rating identical between recommended parts?
A5: Both switches are SPDT, Mom-Off-Mom function, rated at 15A 24V DC, ensuring electrical equivalence within the application.