UB3C-3R9F8 Equivalent & Substitute Parts

Part Overview

The UB3C-3R9F8 is a 3.9 Ohm ±1% 3W through-hole axial wirewound resistor manufactured by Riedon. This component is designed for current sensing applications and features flame-proof, moisture-resistant, and pulse-withstanding characteristics. The part is currently active in production with 998 units in stock. Substitute parts are identified when equivalent electrical specifications, mechanical compatibility, and regulatory compliance can be maintained across different manufacturers.

Substiute Parts

UB3C-3R9F8

RiedonIn Stock: 1069UB3C-3R9F8 Datasheet

Current PartRFQ

RS02B3R900FE70

Vishay DaleIn Stock: 2684RS02B3R900FE70 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the UB3C-3R9F8 is determined by the following criteria:

Resistance value and tolerance must match exactly at 3.9 Ohms ±1%. Power rating must be equal to or greater than 3W. Composition must be wirewound to maintain thermal and electrical characteristics. Package type must be axial to ensure mechanical fit in through-hole applications. Temperature coefficient must be ±50ppm/°C or better. Operating temperature range must encompass or exceed the original specification. RoHS3 compliance and REACH unaffected status must be maintained.

The RS02B3R900FE70 from Vishay Dale meets all substitution criteria and is classified as a manufacturer-recommended equivalent.

Parameter Comparison

Engineering Selection Recommendations

The RS02B3R900FE70 is a valid substitute for the UB3C-3R9F8 based on electrical equivalence and regulatory compliance. Both parts are ROHS3 compliant and REACH unaffected, meeting current environmental standards. The Vishay Dale part extends the lower operating temperature limit to -65°C, providing enhanced performance in cold environments compared to the original specification of -55°C.

Physical dimensions differ between the two parts. The RS02B3R900FE70 is larger in both diameter and length. PCB layout and mechanical clearance must be verified before substitution to ensure the larger package does not create spatial conflicts in the application.

Both parts maintain identical electrical characteristics: 3.9 Ohm resistance, ±1% tolerance, 3W power rating, ±50ppm/°C temperature coefficient, and wirewound composition. These specifications ensure functional equivalence in current sensing applications.

Frequently Asked Questions (FAQ)

Q: Can the RS02B3R900FE70 be used as a direct replacement for the UB3C-3R9F8?

A: Electrical substitution is valid. The RS02B3R900FE70 matches all critical electrical parameters. However, physical dimensions differ. The Vishay Dale part is larger and may require PCB layout verification to confirm mechanical compatibility.

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

A: The primary differences are physical size and operating temperature range. The RS02B3R900FE70 has a larger axial package (0.187" Dia x 0.560" L versus 0.157" Dia x 0.350" L) and extends the minimum operating temperature to -65°C compared to -55°C for the Riedon part. Electrical specifications are identical.

Q: Are both parts suitable for current sensing applications?

A: Yes. Both the UB3C-3R9F8 and RS02B3R900FE70 are wirewound resistors with moisture-resistant characteristics suitable for current sensing. The Riedon part includes additional flame-proof and pulse-withstanding features; the Vishay Dale part specifies moisture resistance.

Q: What packaging formats are available?

A: The UB3C-3R9F8 is supplied in Tape & Reel (TR) format. The RS02B3R900FE70 is supplied in Cut Tape (CT) format. Packaging selection depends on assembly process requirements.

Q: Are both parts RoHS and REACH compliant?

A: Yes. Both the UB3C-3R9F8 and RS02B3R900FE70 are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.