Equivalent & Substitute Parts for 309NPC5K

Part Overview

The 309NPC5K is a 5k Ohm 1 Watt cermet linear panel mount potentiometer manufactured by Honeywell Sensing and Productivity Solutions. This component features a single gang configuration with side adjustment, slotted actuator, and PC pin termination suitable for audio and instrumentation applications. The product is currently classified as obsolete, necessitating identification of active equivalent components that maintain functional and mechanical compatibility for ongoing system support and new designs.

Substiute Parts

309NPC5K

Honeywell Sensing and Productivity SolutionsIn Stock: 1112309NPC5K Datasheet

Current PartRFQ

51CAD-E28-A13L

Bourns Inc.In Stock: 124451CAD-E28-A13L Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 309NPC5K is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Requirements:

• Resistance value: 5k Ohm (exact match)
• Power rating: 1W (exact match)
• Taper characteristic: Linear (exact match)
• Tolerance: ±10% (exact match)
• Resistive material: Cermet (exact match)

Mechanical Equivalence Requirements:

• Termination style: PC Pins (exact match)
• Mounting type: Panel Mount (exact match)
• Bushing thread: 1/4-32 (exact match)
• Actuator type: Slotted (exact match)
• Adjustment type: Side Adjustment (exact match)
• Number of gangs: 1 (exact match)

The substitute part 51CAD-E28-A13L from Bourns Inc. satisfies all critical electrical and mechanical parameters. Minor dimensional variations in actuator length (0.875" vs 0.750") and body size (rectangular vs square profile) do not affect functional compatibility in standard panel mount applications where the potentiometer shaft and bushing thread are the controlling dimensions.

Parameter Comparison

Engineering Selection Recommendations

The 51CAD-E28-A13L potentiometer from Bourns Inc. is a direct functional substitute for the obsolete 309NPC5K. Selection is based on the following engineering criteria:

Electrical Compatibility: All electrical specifications are identical, including resistance value, power rating, tolerance, and taper characteristic. The cermet resistive element provides equivalent performance in audio and instrumentation circuits.

Mechanical Compatibility: The critical mechanical parameters—bushing thread (1/4-32), termination style (PC pins), and actuator diameter (0.125")—are identical. The potentiometer will mount directly to existing panel cutouts and connect to existing PCB layouts without modification.

Compliance Status: The 51CAD-E28-A13L holds active product status with ROHS3 compliance, ensuring long-term availability and regulatory alignment. The 309NPC5K obsolete status creates supply chain risk for new production and field replacements.

Dimensional Considerations: The 51CAD-E28-A13L features a longer actuator shaft (0.875" vs 0.750") and rectangular body profile. These differences do not affect functional performance in standard panel mount applications where the bushing thread and shaft diameter control the interface. Panel depth and knob clearance should be verified for applications with tight mechanical constraints.

Rotation Specification: The 51CAD-E28-A13L rotation of 290° is within 5° of the 309NPC5K specification of 295°. This minor difference is negligible for linear potentiometer applications and does not affect circuit performance.

Frequently Asked Questions (FAQ)

Q: Can the 51CAD-E28-A13L replace the 309NPC5K in existing designs without PCB modification?

A: Yes. The PC pin termination, bushing thread (1/4-32), and actuator diameter are identical. Direct substitution on existing PCBs is possible. Panel mounting holes and knob clearance should be verified due to dimensional differences in body profile and actuator length.

Q: What is the significance of the 5° difference in rotation angle (290° vs 295°)?

A: For linear potentiometer applications, this 5° difference is functionally insignificant. Both specifications provide full-range resistance variation across the adjustment range. This difference does not affect circuit performance or linearity.

Q: Why is the 51CAD-E28-A13L actuator longer (0.875" vs 0.750")?

A: The longer actuator shaft on the 51CAD-E28-A13L is a design feature of the Bourns Pro Audio 51 series. In standard panel mount applications, the excess shaft length does not create compatibility issues. Applications with limited panel depth or specific knob positioning requirements should verify clearance.

Q: Are there compliance differences between the two potentiometers?

A: The 309NPC5K is RoHS Compliant. The 51CAD-E28-A13L is ROHS3 Compliant, representing a more current regulatory standard. Both meet environmental and hazardous substance restrictions. The 51CAD-E28-A13L also carries REACH Affected status, indicating compliance with European chemical regulations.

Q: What is the practical difference between the square and rectangular body profiles?

A: The body profile difference (square 0.500" x 0.500" vs rectangular 0.521" x 0.492") is minor and does not affect panel cutout compatibility. Standard 1/4-32 panel mount potentiometer cutouts accommodate both profiles. Visual appearance and internal panel space utilization may differ slightly.

Q: Is the 51CAD-E28-A13L sealed, and does this affect performance?

A: The 51CAD-E28-A13L includes sealed construction as a feature. This provides enhanced protection against dust and moisture ingress compared to unsealed designs. Sealed construction improves reliability in harsh environments and extends component life without affecting electrical performance.

Q: Why is the 309NPC5K obsolete?

A: The 309NPC5K is classified as obsolete by Honeywell, indicating discontinued production and limited availability. The 51CAD-E28-A13L from Bourns is an active product with confirmed inventory and ongoing manufacturing support, ensuring supply chain continuity for new designs and field replacements.