RT500AS2R70KB Equivalent & Substitute Parts

Part Overview

The RT500AS2R70KB is a 2.7 Ohm, 500W wirewound linear potentiometer manufactured by Vishay Sfernice, designed for panel mount applications with a round actuator and solder turret termination. This component is classified as obsolete, making it necessary to identify functionally equivalent alternatives for ongoing system maintenance and new designs.

Substiute Parts

RT500AS2R70KB

Vishay SferniceIn Stock: 1102RT500AS2R70KB Datasheet

Current PartRFQ

RRS2R5E

OhmiteIn Stock: 1081RRS2R5E Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the RT500AS2R70KB is based on the following critical parameters:

• Power Rating: 500W minimum requirement for thermal performance equivalence
• Resistive Material: Wirewound construction for load handling and stability
• Taper Type: Linear response characteristic
• Mounting Configuration: Panel mount with single gang, single turn design
• Resistance Value: Nominal 2.7 Ohms with ±10% tolerance band

The substitute part RRS2R5E from Ohmite meets these core functional requirements. The resistance value of 2.5 Ohms falls within the acceptable tolerance range for applications designed around the 2.7 Ohm specification, as both values operate within the ±10% tolerance window of typical circuit designs.

Parameter Comparison

Engineering Selection Recommendations

The RRS2R5E from Ohmite is the designated manufacturer-recommended substitute for the obsolete RT500AS2R70KB. Selection of this alternative is supported by:

• Active Product Status: RRS2R5E is in active production, ensuring long-term availability and supply chain stability
• Regulatory Compliance: RRS2R5E is RoHS3 compliant, meeting current environmental and safety standards
• Functional Equivalence: Identical power rating, taper, material composition, and tolerance specifications
• Inventory Availability: 980 units in stock, providing immediate procurement capability

Physical differences in termination style (solder lug vs. solder turret), actuator geometry (flatted vs. round), and body diameter require mechanical and electrical verification during integration. These differences do not affect the electrical performance of the potentiometer but may require PCB layout modifications or panel cutout adjustments.

Frequently Asked Questions (FAQ)

Q: Can the RRS2R5E directly replace the RT500AS2R70KB without modifications?

A: Electrical substitution is valid based on matching power rating, resistance tolerance, and wirewound construction. However, physical integration requires verification of termination compatibility (solder lug vs. turret), actuator fit (flatted vs. round), and panel mounting hole diameter (203.20mm vs. 143.00mm).

Q: What is the significance of the 2.5 Ohm vs. 2.7 Ohm resistance difference?

A: Both values fall within the ±10% tolerance specification. In circuit applications designed for 2.7 Ohms, the 2.5 Ohm substitute introduces a 7.4% reduction in resistance. This is acceptable for most load-sharing and current-limiting applications but should be verified against specific circuit requirements.

Q: Why does the RRS2R5E have a larger body diameter?

A: The 8.000" diameter of the RRS2R5E compared to the 5.630" diameter of the RT500AS2R70KB reflects different mechanical design approaches by the manufacturers. Panel cutout compatibility must be confirmed before installation.

Q: Are there differences in rotation range between these parts?

A: The RT500AS2R70KB provides 300° rotation, while the RRS2R5E provides 325° rotation. The extended range of the substitute does not create incompatibility but may affect adjustment resolution in applications requiring precise control.

Q: What is the difference between solder turret and solder lug termination?

A: Solder turret termination uses a vertical post for PCB mounting, while solder lug termination uses a flat tab. PCB trace routing and solder joint geometry differ between these styles. Verify that the PCB design accommodates the lug termination of the RRS2R5E.