Wire Wound Resistors
0.5W – 12kW
Power Range
Power Range
0.01Ω – 1.2MΩ
Resistance Range
Resistance Range
20 ppm/°C
Best TCR Available
Best TCR Available
±0.01%
Tightest Tolerance
Tightest Tolerance
Certifications:
AEC-Q200
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ISO9001
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IATF16949
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Fusible Models
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TÜV
What Is a Wire Wound Resistor?
A practical overview for engineers and procurement teams evaluating resistive solutions.
A wire wound resistor is made by winding a length of resistive wire — typically a nickel-chromium or copper-nickel alloy — around a ceramic, fiberglass, or plastic core. This construction gives wire wound resistors two key strengths: high power handling ability and the potential for very tight resistance tolerances, depending on the design variant chosen.
At the precision end, RARA's PWR series achieves tolerances as tight as ±0.1% and TCR as low as 20 ppm/°C — making them suitable for instrumentation, calibration standards, and measurement circuits. At the high-power end, edge wound assemblies (EW series) handle up to 12kW of continuous load, suitable for motor control and drive braking applications.
Between those extremes, RARA offers ceramic-encased types for high-temperature environments, fusible wire wound resistors that act as a combined resistor-fuse for overcurrent protection, and non-flammable K-series units for applications where fire risk must be minimized. An AEC-Q200 qualified ceramic variant (AQL) is available for automotive use.
Construction Variants
-Axial wire wound (RW, PWR)
-Ceramic encased (RQA, RQR, RQB, RQL)
-Fusible wire wound (FWR)
-Non-flammable (K, KR series)
-Edge wound (EWS, EW assemblies)
-Axial wire wound (RW, PWR)
-Ceramic encased (RQA, RQR, RQB, RQL)
-Fusible wire wound (FWR)
-Non-flammable (K, KR series)
-Edge wound (EWS, EW assemblies)
Key Advantages
-High temperature tolerance by design
-Precision tolerances down to ±0.1%
-TCR as low as 20 ppm/°C (PWR series)
-AEC-Q200 automotive-qualified variant
-STEP files available for major models
-High temperature tolerance by design
-Precision tolerances down to ±0.1%
-TCR as low as 20 ppm/°C (PWR series)
-AEC-Q200 automotive-qualified variant
-STEP files available for major models
RARA wire wound resistors span a wide range of designs — from 0.5W precision axial types to 12kW edge wound assemblies — all sharing the robust, high-temperature tolerance that wire wound construction provides.
Applications
Where RARA wire wound resistors are deployed in the field.
Precision Instrumentation
The PWR precision wire wound series — with tolerances to ±0.1% and TCR as low as 20 ppm/°C — is used in measurement instruments, calibration references, Wheatstone bridge circuits, and analog signal conditioning where stable, accurate resistance is critical.
The PWR precision wire wound series — with tolerances to ±0.1% and TCR as low as 20 ppm/°C — is used in measurement instruments, calibration references, Wheatstone bridge circuits, and analog signal conditioning where stable, accurate resistance is critical.
High-Temperature Environments
Ceramic-encased wire wound resistors (RQA, RQR, RQB, RQL) are built to withstand high operating temperatures that would degrade film or carbon resistors — making them ideal for engine compartments, furnace controls, and industrial ovens.
Ceramic-encased wire wound resistors (RQA, RQR, RQB, RQL) are built to withstand high operating temperatures that would degrade film or carbon resistors — making them ideal for engine compartments, furnace controls, and industrial ovens.
Overcurrent & Fuse Protection
The FWR fusible wire wound series acts as a combined resistor and fuse — opening the circuit under overload conditions. Used in power supply inrush limiting, motor starting circuits, and anywhere a single component needs to provide both resistance and overcurrent protection.
The FWR fusible wire wound series acts as a combined resistor and fuse — opening the circuit under overload conditions. Used in power supply inrush limiting, motor starting circuits, and anywhere a single component needs to provide both resistance and overcurrent protection.
Automotive Systems
The AQL series is AEC-Q200 qualified and ceramic encased for use in automotive applications including battery management, HVAC blower control, and powertrain modules where resistors must survive automotive temperature cycling and vibration.
The AQL series is AEC-Q200 qualified and ceramic encased for use in automotive applications including battery management, HVAC blower control, and powertrain modules where resistors must survive automotive temperature cycling and vibration.
Motor Control & Edge Wound Braking
The EWS and EW edge wound series (400W–12kW) are designed for high-energy braking and motor control applications — dissipating regenerative energy in crane drives, elevator controllers, and large servo systems where low resistance values and high pulse power are required.
The EWS and EW edge wound series (400W–12kW) are designed for high-energy braking and motor control applications — dissipating regenerative energy in crane drives, elevator controllers, and large servo systems where low resistance values and high pulse power are required.
Industrial Power & Load Banks
The non-flammable K-series (15W–2000W) and KR series (120W–600W) provide safe, stable resistive loads in switchgear panels, control cabinets, and industrial test equipment where regulatory requirements demand non-flammable components.
The non-flammable K-series (15W–2000W) and KR series (120W–600W) provide safe, stable resistive loads in switchgear panels, control cabinets, and industrial test equipment where regulatory requirements demand non-flammable components.
Product Series
Select models from our wire wound lineup. Download individual datasheets for full specifications, dimensions, and ordering codes.
Model: SMW
Resistor type: Wire wound
Description: Power chip
Power Rating: 2W, 3W, 5W
Resistance (Ω): 0.1~680
Tolerance (%): ±1, ±2, ±3, ±5, ±10
TCR (ppm/C): 200
Model: FWR
Resistor type: Wire wound
Description: Fusible
Power Rating: 1W, 2W, 3W, 5W
Resistance (Ω): 0.1~200
Tolerance (%): ±5
TCR (ppm/C): 300
Model: RW
Resistor type: Wire wound
Description: Wire wound
Power Rating: 0.5W~10W
Resistance (Ω): 0.1~680
Tolerance (%): ±1, ±2, ±3, ±5, ±10
TCR (ppm/C): 260 max.
Model: PWR
Resistor type: Wire wound
Description: Precision wire wound
Power Rating: 0.5W~10W
Resistance (Ω): 0.1~100k
Tolerance (%): ±0.1, ±0.25, ±0.5, ±1, ±2
TCR (ppm/C): 20, 50, 90
Model: RQA
Resistor type: Wire wound
Description: Ceramic encased
Power Rating: 5W~20W
Resistance (Ω): 0.1~100k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260, 400
Model: RQR
RResistor type: Wire wound
Description: Ceramic encased
Power Rating: 2W~12W
Resistance (Ω): 0.1~75k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260, 400
Model: RQR15~40
Resistor type: Wire wound
Description: Ceramic encased
Power Rating: 15W~40W
Resistance (Ω): 0.01~54k
Tolerance (%): ±0.5, ±1, ±2, ±5, ±10
TCR (ppm/C): 260 (max.)
Model: RQB
Resistor type: Wire wound
Description: Ceramic encased
Power Rating: 5W~20W
Resistance (Ω): 0.1~100k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260, 400
Model: RQL
Resistor type: Wire wound
Description: Ceramic encased
Power Rating: 10W~40W
Resistance (Ω): 0.3~100k
Tolerance (%): ±5, ±10
TCR (ppm/C): 260, 400
Model: AQL
Resistor type: Wire wound
Description: AEC-Q200, ceramic encased
Power Rating: 20W~60W
Resistance (Ω): 20~80
Tolerance (%): ±5
TCR (ppm/C): 260 max.
Model: KR
Resistor type: Wire wound
Description: Non-flammable
Power Rating: 120W~600W
Resistance (Ω): 0.2~20
Tolerance (%): ±10
TCR (ppm/C): 400 max.
Model: K
Resistor type: Wire wound
Description: Non-flammable
Power Rating: 15W-2000W
Resistance (Ω): 1~1200k
Tolerance (%): ±5, ±10
TCR (ppm/C): 200 max.
Model: EWS
Resistor type: Wire wound
Description: Edge wound
Power Rating: 400W~1600W
Resistance (Ω): 0.02~1
Tolerance (%): ±5, ±10
TCR (ppm/C): 800 max.
Model: EW
Resistor type: Wire wound
Description: Edge wound assembly
Power Rating: 3kW~12kW
Resistance (Ω): 0.05~48
Tolerance (%): ±5, ±10
TCR (ppm/C): 800 max.
Model: DBR
Resistor type: Wire wound
Description: Dynamic braking
Power Rating: 8kW~60kW
Resistance (Ω): 1~150
Tolerance (%): ±5, ±10
TCR (ppm/C): 800 max.
Model: RLB
Resistor type: Wire wound
Description: Load bank
Power Rating: 50kW~3000kW
Resistance (Ω): 0.1~1M
Tolerance (%): ±5, ±10
TCR (ppm/C): 200
Why Choose RARA Wire Wound Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
Widest Design Range
From 0.5W precision types to 12kW edge wound assemblies — one wire wound product family covering precision, ceramic-encased, fusible, non-flammable, and high-power variants.
Widest Design Range
From 0.5W precision types to 12kW edge wound assemblies — one wire wound product family covering precision, ceramic-encased, fusible, non-flammable, and high-power variants.
02
Precision Available
The PWR series delivers ±0.1% tolerance and TCR as low as 20 ppm/°C — precision wire wound performance for instrumentation and measurement circuits.
Precision Available
The PWR series delivers ±0.1% tolerance and TCR as low as 20 ppm/°C — precision wire wound performance for instrumentation and measurement circuits.
03
Automotive Qualified
The AQL ceramic-encased series is AEC-Q200 qualified for automotive-grade reliability in EV battery management, HVAC, and powertrain applications.
Automotive Qualified
The AQL ceramic-encased series is AEC-Q200 qualified for automotive-grade reliability in EV battery management, HVAC, and powertrain applications.
04
Global Track Record
Trusted by Siemens, Rockwell, Toshiba, Schneider Electric, LG, and Hanwha — a customer base built on decades of consistent, certified performance.
Global Track Record
Trusted by Siemens, Rockwell, Toshiba, Schneider Electric, LG, and Hanwha — a customer base built on decades of consistent, certified performance.
Products & Downloads
Information & Schedule
100B-11L, 138 Cheongneung-
daero 410beon-gil,
Namdong-gu, Incheon
TEL : +82-70-4355-4327
FAX : +82-32-817-4328
Email: osm1@raraohm.com
daero 410beon-gil,
Namdong-gu, Incheon
TEL : +82-70-4355-4327
FAX : +82-32-817-4328
Email: osm1@raraohm.com
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