UB3C-12RF8 Equivalent & Substitute Parts

Part Overview

The UB3C-12RF8 is a 12 Ohm ±1% 3W axial wirewound resistor manufactured by Riedon. This through-hole component is designed for current sensing applications and features flame-proof, moisture-resistant, pulse-withstanding, and safety-rated construction. The part is currently active in production with 685 units in stock. Equivalent and substitute parts are identified when identical electrical specifications and mechanical compatibility are maintained across alternative manufacturers.

Key Parameters

Parameter	Value
Resistance	12 Ohms
Tolerance	±1%
Power Rating	3W
Composition	Wirewound
Package Type	Axial
Temperature Coefficient	±20ppm/°C
Operating Temperature Range	-55°C ~ 250°C
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)

Substitute Part Grouping Explanation

Substitute parts for the UB3C-12RF8 are qualified based on the following criteria:

Resistance value: 12 Ohms
Tolerance: ±1%
Power rating: 3W
Composition: Wirewound
Package: Axial through-hole
Temperature coefficient: ±20ppm/°C
RoHS3 compliance
Number of terminations: 2

All identified substitutes maintain these core electrical and mechanical specifications, ensuring functional equivalence in circuit applications. Variations in physical dimensions, operating temperature ranges, and packaging formats (Tape & Reel vs. Cut Tape vs. Bulk) do not affect electrical performance but may impact procurement and assembly workflows.

Parameter Comparison

Parameter	UB3C-12RF8 (Riedon)	43F12RE (Ohmite)	RS02B12R00FE70 (Vishay Dale)	WW3FT12R0 (Stackpole)
Resistance	12 Ohms	12 Ohms	12 Ohms	12 Ohms
Tolerance	±1%	±1%	±1%	±1%
Power (Watts)	3W	3W	3W	3W
Composition	Wirewound	Wirewound	Wirewound	Wirewound
Package / Case	Axial	Axial	Axial	Axial
Temperature Coefficient	±20ppm/°C	±20ppm/°C	±20ppm/°C	±20ppm/°C
Operating Temperature	-55°C ~ 250°C	Not specified	-65°C ~ 250°C	-55°C ~ 350°C
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)	Not Applicable	Not Applicable	Not Applicable
Size / Dimension	0.157" Dia x 0.350" L (4.00mm x 8.90mm)	0.220" Dia x 0.594" L (5.60mm x 15.10mm)	0.187" Dia x 0.560" L (4.75mm x 14.22mm)	0.187" Dia x 0.560" L (4.75mm x 14.22mm)
Packaging Format	Tape & Reel (TR)	Bulk	Cut Tape (CT)	Cut Tape (CT)
Inventory Availability	685 Pcs	779 Pcs	1573 Pcs	7723 Pcs

Engineering Selection Recommendations

All substitute parts maintain electrical equivalence to the UB3C-12RF8 through identical resistance, tolerance, power rating, and temperature coefficient specifications. Selection among these alternatives should be based on:

Compliance and Certification: All parts are ROHS3 compliant and REACH unaffected, meeting regulatory requirements for the UB3C-12RF8 application.

Operating Temperature Range: The WW3FT12R0 (Stackpole) extends to 350°C, providing the widest thermal operating window. The RS02B12R00FE70 (Vishay Dale) extends to -65°C, offering the lowest temperature capability. The UB3C-12RF8 and 43F12RE operate within -55°C to 250°C and unspecified ranges respectively.

Physical Dimensions: The UB3C-12RF8 features the smallest form factor (4.00mm diameter x 8.90mm length). The 43F12RE is the largest (5.60mm diameter x 15.10mm length). The RS02B12R00FE70 and WW3FT12R0 are identical in size (4.75mm diameter x 14.22mm length).

Packaging and Availability: The WW3FT12R0 offers the highest inventory level (7723 units). Packaging formats vary between Tape & Reel, Cut Tape, and Bulk, which may affect procurement lead times and assembly automation compatibility.

Frequently Asked Questions (FAQ)

Q: Can the 43F12RE (Ohmite) directly replace the UB3C-12RF8 (Riedon)?

A: Yes, electrically. The 43F12RE maintains identical resistance (12 Ohms), tolerance (±1%), power rating (3W), composition (wirewound), and temperature coefficient (±20ppm/°C). However, the 43F12RE is physically larger (5.60mm diameter x 15.10mm length versus 4.00mm x 8.90mm) and is supplied in Bulk packaging rather than Tape & Reel. PCB layout and assembly process compatibility must be evaluated.

Q: What are the key differences between the RS02B12R00FE70 and WW3FT12R0?

A: Both parts are electrically identical and share the same physical dimensions (4.75mm diameter x 14.22mm length). The RS02B12R00FE70 (Vishay Dale) operates from -65°C to 250°C, while the WW3FT12R0 (Stackpole) operates from -55°C to 350°C. The WW3FT12R0 has significantly higher inventory availability (7723 units versus 1573 units).

Q: Are there moisture resistance differences between these substitutes?

A: The UB3C-12RF8 specifies moisture resistance as a feature with MSL 1 (Unlimited). The RS02B12R00FE70 and WW3FT12R0 both feature moisture resistance with MSL Not Applicable. The 43F12RE does not specify moisture resistance features. For applications requiring moisture protection, the RS02B12R00FE70 or WW3FT12R0 are preferred.

Q: Can these parts be used interchangeably in current sensing applications?

A: Yes. All parts are wirewound composition with ±1% tolerance and ±20ppm/°C temperature coefficient, meeting the precision requirements for current sensing circuits. The UB3C-12RF8 specifically notes current sensing as an application feature, and all substitutes maintain this capability through identical electrical specifications.

Q: What packaging considerations apply when selecting a substitute?

A: The UB3C-12RF8 is supplied in Tape & Reel format for automated assembly. The 43F12RE is Bulk packaging, requiring manual handling. The RS02B12R00FE70 and WW3FT12R0 are Cut Tape format. Packaging selection impacts assembly line compatibility, component feeding systems, and procurement workflows.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message