K Series Non-Flammable Wire Wound Resistors
Non-flammable wire wound resistive element on ceramic core
Power rating from 15W to 2000W
Resistance range 1Ω to 1.2MΩ
Tolerance options ±5% and ±10%
TCR ±200ppm/°C maximum
Wide operating temperature range
Multiple power ratings covering low- to high-power industrial requirements
What are the K Series Non-Flammable Wire Wound Resistors?
The K Series is a range of non-flammable wire wound resistors designed for industrial applications where fire safety is a regulatory or practical requirement. Resistance wire is wound around a ceramic core and the assembly is enclosed in a non-flammable housing that will not ignite or sustain combustion even under sustained overload conditions. This construction gives the K Series its primary advantage over standard cement or epoxy-coated wire wound types — the ceramic enclosure remains stable at high surface temperatures, making the series suitable for installation in enclosed switchgear panels, control cabinets, and industrial assemblies where the consequences of a resistor fire would be severe.
The power range of the K Series spans 15W to 2000W, covering the full breadth of industrial panel and control system requirements from small signal-conditioning loads through to high-power braking and discharge circuits. The resistance range extends from 1Ω to 1.2MΩ, giving designers flexibility to specify the same series across a wide variety of circuit impedance requirements. Tolerance options of ±5% and ±10% are available, with a temperature coefficient of resistance (TCR) of ±200ppm/°C maximum — a level appropriate for the power control and load applications that characterise the K Series’ primary use cases.
The wire wound construction used in the K Series provides inherently high pulse power capability compared to film-based resistor technologies. The resistance wire element can absorb transient energy well in excess of its rated continuous dissipation, making the series robust in applications subject to repetitive current surges, switching transients, and motor starting loads. The ceramic core also provides good dimensional stability over the operating temperature range, preventing deformation that could affect resistance value stability during repeated thermal cycling.
The K Series sits alongside the KR Series in RARA’s non-flammable wire wound line. While the KR Series is optimised for lower resistance values (0.2Ω to 20Ω) at power ratings of 120W to 600W — targeting braking and low-impedance discharge applications — the K Series covers the full resistance spectrum up to 1.2MΩ and extends the power range from 15W upward. Together, the two series provide a comprehensive non-flammable resistor offering for industrial electrical installations.
K Series Non-Flammable Wire Wound Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
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.
Applications of the K Series Non-Flammable Wire Wound Resistors
Where RARA wire wound resistors are deployed in the field.
Industrial switchgear and control panels — non-flammable load and discharge resistors in enclosed assemblies where fire risk must be minimised
Motor drive and variable-speed drive circuits — braking resistors and DC bus discharge networks requiring stable high-power dissipation
Power supply and UPS systems — bleeder, load, and pre-charge resistors in high-voltage DC circuits
Industrial test equipment and load banks — stable precision load resistors across a wide resistance range
Energy storage and renewable energy systems — dump load and crowbar resistor assemblies in solar and wind power installations
Elevator and crane control systems — starting and braking resistors subject to repetitive duty cycles in environments with strict fire safety regulations
Heating and industrial process control — current-limiting and voltage-divider resistors in furnace control and process automation panels
Telecommunications power equipment — high-power filtering and protection resistors in rectifier and battery backup systems
Related Products of the K Series Non-Flammable Wire Wound Resistors
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.
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.
03
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.
