WW3FTR250 Equivalent & Substitute Parts

Part Overview

The WW3FTR250 is a 250 mOhms ±1% 3W axial wirewound resistor manufactured by Stackpole Electronics Inc. This through-hole component features moisture-resistant construction and is designed for applications requiring precision low-resistance dissipation in compact form factors. The part maintains Active product status with 1450 units in current inventory stock.

Substitute parts are identified when equivalent electrical specifications and mechanical compatibility are maintained across the core parameters: resistance value, tolerance, power rating, composition type, and axial package configuration.

Substiute Parts

WW3FTR250

Stackpole Electronics IncIn Stock: 1531WW3FTR250 Datasheet

Current PartRFQ

43FR25E

OhmiteIn Stock: 90543FR25E Datasheet

MFR RecommendedRFQ

RS02BR2500FE70

Vishay DaleIn Stock: 5348RS02BR2500FE70 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the WW3FTR250 is determined by strict equivalence across the following parameters:

• Resistance value: 250 mOhms (exact match required)
• Tolerance: ±1% (exact match required)
• Power rating: 3W (exact match required)
• Composition: Wirewound (exact match required)
• Package configuration: Axial through-hole (exact match required)
• Termination count: 2 (exact match required)

The identified substitute parts—43FR25E (Ohmite) and RS02BR2500FE70 (Vishay Dale)—meet all core electrical and mechanical criteria. Physical dimensions may vary within acceptable tolerances for axial component mounting. Compliance certifications and operating temperature ranges are provided as secondary selection factors.

Parameter Comparison

Engineering Selection Recommendations

All three parts—WW3FTR250, 43FR25E, and RS02BR2500FE70—maintain Active product status and meet core electrical specifications for 250 mOhms ±1% 3W axial wirewound resistor applications.

WW3FTR250 and RS02BR2500FE70 share identical physical dimensions (0.187" Dia x 0.560" L) and both feature moisture-resistant construction with ROHS3 compliance. RS02BR2500FE70 offers the highest current inventory availability at 5261 units.

43FR25E (Ohmite) presents a dimensional variation with a larger diameter (0.220" Dia) and length (0.594" L). This part is suitable for applications where board space permits the increased footprint. Ohmite 43FR25E carries standard RoHS compliance and MSL rating of 1 (Unlimited).

Selection between these parts should account for: (1) available board space and mounting constraints, (2) required operating temperature range, (3) inventory availability, and (4) packaging format requirements (Cut Tape versus Bulk).

Frequently Asked Questions (FAQ)

Q: Can 43FR25E replace WW3FTR250 in a PCB layout without modification?

A: 43FR25E has different physical dimensions (0.220" Dia x 0.594" L versus 0.187" Dia x 0.560" L). Board layout and mounting hole spacing must accommodate the larger diameter and length. Mechanical clearance verification is required before substitution.

Q: What is the primary difference between WW3FTR250 and RS02BR2500FE70?

A: Both parts share identical resistance, tolerance, power rating, composition, and physical dimensions. RS02BR2500FE70 operates across a narrower temperature range (-65°C ~ 250°C versus -55°C ~ 350°C). Selection depends on application temperature requirements and inventory availability.

Q: Are all three parts RoHS compliant?

A: WW3FTR250 and RS02BR2500FE70 are ROHS3 Compliant. 43FR25E is RoHS Compliant. Both certifications satisfy RoHS Directive requirements; ROHS3 represents the current standard revision.

Q: Which substitute offers the best inventory availability?

A: RS02BR2500FE70 (Vishay Dale) provides the highest stock level at 5261 units, compared to 1450 units for WW3FTR250 and 825 units for 43FR25E.

Q: Does packaging format affect electrical performance?

A: No. WW3FTR250 is supplied in Cut Tape (CT) packaging, while 43FR25E is supplied in Bulk. Packaging format affects logistics and handling only; electrical specifications remain identical.

Q: What is the significance of moisture-resistant construction?

A: WW3FTR250 and RS02BR2500FE70 feature moisture-resistant construction. This specification is not provided for 43FR25E. Moisture resistance is relevant for applications exposed to humidity or condensation environments.