High-voltage resistors

High voltage resistors from REO

Resistors that withstand high voltages and high temperatures

High voltage resistors are subject to particular requirements as a result of their areas of application.
The highest level of functional safety and service life paired with an extreme level of robustness against adverse environmental pressures are as a result absolutely essential.

REO high voltage resistors undergo the following tests:
• Climatic fluctuation testing
• Vibration and shock testing, simulated service life testing
• Self-heating measurement
• High voltage testing
• Insulation measurement

  • REOHM series 155

    Max. continous power: 3.000 W

    BW 156
    • Resistance values: 0,5 - 1440 Ohm
    • Continuous power: 500 - 3500 W
    • max. operating voltage: 900 - 4200 V

    Braking resistor for drives with frequency converters of medium to high power.
    Mounting inside and outside the control cabinet is possible.

    • degree of protection: IP20 / IP65 / IP66

    • test voltage: 2.5 kV AC

    • ambient temperature: 10+40 ºC

    • other services on request

    • other fastenings on request

  • REOHM series NTT R D 158

    Max. continous power: 2600 W

    BW 156
    • Resistance values: 0,1 - 1 Ohm
    • Continuous power: 100 - 1210 W
    • max. operating voltage: 4200 V

    The resistor NTT RD 158 is a water-cooled damping resistor, which is used for traction in railway applications. The resistor is used in series with filter capacitors in the 1.5 kV and 3 kV DC network. 

    For this purpose, the device must be designed for a high single pulse energy and nominal voltage. The inductance of the resistor contributes to limit the inrush current - here are wirewound resistors the right choice.

    The advantage of the resistance unit NTT R D158 is that 4 damping resistors are housed in one unit. This means a compact construction and low cost when connecting the resistor.

    REO high-voltage resistors are designed, produced and certified specifically for the railway technology. The specially designed winding technology allows a higher withstand voltage due to the spatial separation of the wires. The use of railway-compatible, high quality materials, together with the complete encapsulation in profile design lead to protection classes up to IP 65.

    Maximum energy with minimum space

    • Continuous output: 2600 W

    • Max. operating voltage: 4200V

    • Resistance value: 0,1 - 1Ohm

    • Average pulse load: 1x per hour 20kWs - within 100ms

    • Maximum pulse load: 20x per year 120kWs -within 20ms

    • Protection class: IP00-IP65

    • Other ratings upon request

  • REOhm series R 157

    Max. continous power: 300 W

    BW 156
    • Resistance values: 20 - 8000 Ohm
    • Continuous power: 150 - 300 W
    • max. operating voltage: 4200 V

    High voltage resistor for drives with frequency converters of small to medium output, installation close to the frequency converter. They are used to damp over-voltages or to dissipate excess energy that originates, for example, on braking or starting up. This is done by converting the electrical energy into heat in the resistor. 

    Due to their special application, these resistors are are subject to special requirements. Highest reliability and durability combined with an extreme resistance to adverse environmental impacts are therefore absolutely necessary.


    • Protection ratings IP 20 / IP 40 / IP 54

    • Higher IP ratings upon request

    • Test voltage: 10,5 kV DC und 8,3 kV AC

    • Other ratings and fastening dimensions upon request




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    Air-cooled Resistors catalogue

    Air-cooled Resistors catalogue

    Product catalogue for Air-cooled Resistors