RQR Series Ceramic Encased Wire Wound Resistors
Wire Wound resistive element encased in a fired ceramic cement housing
Power ratings: 2W, 3W, 5W, 7W, 10W and 12W
Resistance range: 0.1Ω to 75kΩ depending on core type and power rating
Three element types: Glass Fibre Core (GC), Ceramic Core (CC) and Metal Oxide Film (MO)
Tolerance: ±5% for R>1Ω; ±10% for R≤1Ω
TCR: 490ppm/°C for R≥ 1Ω; 490 to 1300ppm/°C for R< 1Ω
Operating temperature range: −25°C to +155°C
Dielectric withstanding voltage: AC 1500V for 1 minute
Insulation resistance: 20MΩ minimum at DC 500V
Short-time overload: 10× rated power for 5 seconds
Compact upright radial package; RoHS compliant
What are the RQR Series Ceramic Encased Wire Wound Resistors?
The RQR is a ceramic encased Wire Wound resistor — a construction type widely referred to in the industry as a cement resistor — offered in a compact upright radial package that occupies a smaller PCB footprint than axial-format types of equivalent power rating. The resistive element is formed by winding precision resistance wire onto a glass fibre or ceramic core, or by depositing a metal oxide film onto a ceramic rod; the assembly is then placed into a ceramic boat, filled with high-temperature fire-retardant cement and fired to produce a rigid, sealed enclosure. This construction results in a component that delivers reliable power dissipation in environments where temperature, humidity, shock and vibration would degrade or destroy standard silicone-coated axial resistors.
Three element types are offered within the RQR series, each addressing a different segment of the resistance range. The Glass Fibre Core variant (GC) covers the lowest resistance values within each power rating, reaching down to 0.1Ω on the 2W through 5W models — making it the preferred choice for low-impedance current-limiting and power dissipation applications. The Ceramic Core variant (CC) extends the Wire Wound range to higher resistances, reaching 10kΩ on the 10W and 12W models. The Metal Oxide Film variant (MO) covers the high-resistance portion of the range from 10Ω up to 75kΩ, and is available across the 2W through 10W ratings. This three-way structure allows the RQR platform to serve an unusually wide resistance span — 0.1Ω to 75kΩ — within a single compact radial package family.
The series covers power ratings of 2W, 3W, 5W, 7W, 10W and 12W. Tolerance is ±5% for resistance values above 1Ω and ±10% for values at or below 1Ω. The TCR is 490ppm/°C for resistances of 1Ω and above, rising to between 490 and 1300ppm/°C for sub-1Ω values where the low resistance wire composition inherently produces a higher temperature coefficient. The operating temperature range is −25°C to +155°C, and full rated power is based on operation at 70°C ambient with derating applied at higher temperatures. The dielectric withstanding voltage of AC 1500V for one minute is notably higher than many comparable axial cement types, confirming suitability for industrial line-voltage environments. Insulation resistance is a minimum of 20MΩ at DC 500V.
Short-time overload performance is rated at ten times the nominal power for five seconds, with a resistance change limit of ±(2% + 0.05Ω). Moisture resistance testing at DC 100V, 40°C and 95% relative humidity for 500 hours holds resistance change within ±(3% + 0.05Ω). Thermal shock testing between −25°C and the rated operating temperature also imposes a ±(2% + 0.05Ω) limit. Long-term load life and moisture load life endurance at 90-minute on, 30-minute off cycles confirm resistance stability within ±(5% + 0.05Ω) and ±(3% + 0.05Ω) respectively. The compact radial body dimensions — ranging from 11mm wide by 7mm deep by 20.5mm tall for the 2W variant up to 18mm wide by 10mm deep by 32mm tall for the 12W variant — allow dense board-level placement at power levels that would otherwise require significantly larger axial components.
RQR Series Ceramic Encased Wire Wound Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
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
Applications of the RQR Series Ceramic Encased Wire Wound Resistors
Where RARA wire wound resistors are deployed in the field.
Compact power supply and converter circuits — board-mounted discharge, bleed and current-limiting resistors where the radial package delivers higher power density in a smaller PCB area than axial-format alternatives, making the RQR well suited to space-constrained designs in switched-mode and linear power supplies
Industrial control and automation panels — snubber networks, voltage dividers and protective series resistors in variable-frequency drive panels, motor starters and relay control circuits where elevated enclosure temperatures demand ceramic-encased construction and the compact radial format aids density in standard DIN-rail mounted assemblies
High-voltage circuit protection — the AC 1500V dielectric withstanding voltage makes the RQR suitable for series and discharge applications in equipment connected directly to industrial line voltages, including capacitor discharge networks, gate drive damping and inrush-limiting circuits
Consumer electronics and appliance circuits — power dissipation elements in television power stages, air conditioning control boards, washing machine motor drivers and other white goods where a compact, robust cement resistor replaces a larger axial type, reducing board space and improving thermal reliability in enclosed plastic assemblies
High-humidity and harsh-environment equipment — the sealed ceramic cement housing prevents moisture ingress in outdoor switchgear, agricultural and horticultural control equipment, marine auxiliary electronics and coastal industrial installations where condensation and salt-laden air degrade unsealed resistors over time
Automotive auxiliary and body electronics — resistive elements in HVAC blower speed control, seat heating controllers, lighting ballast circuits and body module power stages where the combination of vibration, thermal cycling and humidity demands the mechanical robustness of a fired ceramic enclosure in a board-mountable radial package
Telecommunications and infrastructure equipment — line protection, load balancing and power conditioning resistors in base station power supplies, rectifier modules and outdoor cabinet electronics where the high insulation voltage and moisture resistance of the RQR support reliable long-term deployment in uncontrolled environments
Renewable energy and power conversion — damping and discharge resistors in solar inverter input stages, battery charge controller circuits and energy storage systems where wide operating temperature range and resistance to humidity are required in equipment installed in outdoor enclosures or thermally demanding locations
Related Products of the RQR Series Ceramic Encased Wire Wound Resistors
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: 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: 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
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.
