WCR500 / WCR1000 Series Water Cooled High Power Film Resistors
Water cooled thick film power resistors — 500W (WCR500) and 1000W (WCR1000)
Very low inductance flat resistive element construction
High surge handling capacity
Resistance range: 10Ω, 20Ω, 40Ω, 120Ω
Tolerance: K = ±10%
TCR: ±250 ppm/°C
Dielectric strength: AC 2000V (standard); DC 5000V between terminals and fin (option)
Series inductance: 40nH per dual resistor (typical); 0.1µH maximum
Alumina (Al₂O₃) substrate for superior dielectric isolation
Minimum water flow: 2 L/min (WCR500); 6 L/min (WCR1000)
Maximum inlet water temperature: 41°C
Reference standard: JIS C 5201-1
What are the WCR500 / WCR1000 Series Water Cooled High Power Film Resistors?
The WCR series comprises water cooled thick film power resistors rated at 500W (WCR500) and 1000W (WCR1000), engineered for high-density power electronics equipment where conventional air-cooled or chassis-mount resistors cannot achieve the required power dissipation within the available footprint. Direct liquid cooling eliminates the need for an external heat sink entirely, allowing the WCR to achieve continuous power ratings that would be impractical in an equivalently sized air-cooled design. The flat resistive element construction, combined with twisted lead geometry, results in very low series inductance — specified at 40nH per dual resistor (typical) and 0.1µH maximum — making the WCR well suited to snubber circuits, GTO and IGBT gate networks, and other high-frequency power conversion topologies where parasitic inductance must be minimised.
An alumina (Al₂O₃) ceramic substrate interposes between the thick film resistive element and the water-cooled metal housing, delivering both electrical isolation and efficient thermal coupling. Standard dielectric withstanding voltage is AC 2000V between terminals and fin, with a DC 5000V option available. The WCR500 requires a minimum water flow rate of 2 L/min and achieves a case temperature rise of 14°C and a water temperature rise of 1.4°C at rated power. The WCR1000 requires a minimum of 6 L/min. Both models specify a maximum inlet water temperature of 41°C, a maximum element surface temperature of 110°C, and a maximum surface temperature rise of 50°C. Pressure loss across the cooling circuit is 0.06 kgf/cm² (WCR500) and 0.1 kgf/cm² (WCR1000). Standard hose connections are nipple fittings; alternative port types are available on request.
The WCR is offered in four resistance values — 10Ω, 20Ω, 40Ω, and 120Ω — with a tolerance of ±10% (K code) and a temperature coefficient of resistance (TCR) of ±250 ppm/°C. The very low operating temperature of the resistive element, enabled by direct water cooling, contributes to a low failure rate in compact, high-density instruments and equipment. Load life performance and impulse surge capacity make the WCR appropriate for demanding repetitive-duty applications in electric power conversion systems including motor drives, energy storage, and renewable energy inverters. Ordering follows a structured part number format covering series name, power rating, tolerance, TCR, and resistance value. The WCR conforms to JIS C 5201-1 reference standards.
WCR500 / WCR1000 Series Water Cooled High Power Film Resistors Specifications
A practical overview for engineers and procurement teams evaluating resistive solutions.
Model: WCR
Resistor type: Power film
Description: Water cooled
Power Rating: 500W, 1000W
Resistance (Ω): 5~1k
Tolerance (%): ±10
TCR (ppm/C): 250
Applications of the WCR500 / WCR1000 Series Water Cooled High Power Film Resistors
Where RARA metal clad resistors are deployed in the field.
-Snubber resistors in GTO, IGBT, and thyristor power converter circuits — transient voltage suppression and dV/dt limiting
-High-power inverter and motor drive systems requiring compact, continuous-duty dissipation without a dedicated heat sink
-Electric power conversion systems — regenerative braking energy absorption and DC bus clamping
-Renewable energy inverters — wind, solar, and tidal power conversion equipment requiring reliable high-power dissipation
-Energy storage systems (ESS) — controlled discharge and grid stabilisation resistor banks
-High-density compact instruments and industrial equipment where low element temperature reduces failure rate
-Pulsed power and capacitor bank discharge circuits requiring high surge handling capacity
-High-frequency power electronics where low inductance (40nH typical) is required to avoid resonance and switching artefacts
-Test bench and dynamometer load banks for power supply and drive characterisation at 500W to 1000W continuous
Related Products of the WCR500 / WCR1000 Series Water Cooled High Power Film Resistors
Model: TPX600L
Resistor type: Power film
Description: Chassis mounted
Power Rating: 600W
Resistance (Ω): 10~1k
Tolerance (%): ±5
TCR (ppm/C): 50
Model: TPK600, TPK900
Resistor type: Power film
Description: Chassis mounted
Power Rating: 600W, 900W
Resistance (Ω): 10~1.6k
Tolerance (%): ±5
TCR (ppm/C): 50
Model: TPU
Resistor type: Power film
Description: Chassis mounted
Power Rating: 300W, 600W, 800W
Resistance (Ω): 4.7~500M
Tolerance (%): ±1, ±2, ±5, ±10
TCR (ppm/C): 50-250.
Model: TPM150~600
Resistor type: Power film
Description: Chassis mounted
Power Rating: 150W~600W
Resistance (Ω): 0.1~1M
Tolerance (%): ±5
TCR (ppm/C): 100
Why Choose RARA Metal Clad Resistors
What sets RARA apart for engineers and procurement managers in industrial and automotive markets.
01
Automotive Qualified
AEC-Q200 tested models and IATF 16949 certification for EV and automotive powertrain applications. Trusted by GM Korea, Tesla, and Proterra.
02
STEP Files Included
3D STEP files available for core models, supporting ECAD/MCAD integration and thermal management simulation in your design workflow.
03
Wide Power Range
A single product family spanning 10W to 8.5kW means you can source across a project from one qualified, certified supplier.
04
Global Track Record
Deployed by Siemens, Rockwell, Toshiba, Schneider Electric, LG, and Hanwha — a customer list built on decades of consistent performance.
