Product Overview Power Resistors - Ruhstrat GmbH

Ruhstrat — Your competent partner for power resistorsFor more than 100 years Ruhstrat power resistors have been used all around the world in many electrotechnical fields. Our conceptis to offer complete solutions and to be a reliable partner for our customers. We develop and manufacture power resistors for a largevariety of different technical applications, in a power range from 10 W up to several 1000 kW.Ruhstrat is not only characterized by a broad application programme but most notably by the know-how concerning project planningof various resistor plants. According to the requirements and specifications of the respective project we dimension and manufacturethe desired resistor plant.Power resistors as wirewoundresistor elementsFor the winding of the resistors round resistorwire or band made of Isotan CuNi44is used, with a very small thermal coefficientof resistance. Our resistor elements are outstandinglysuitable, specially for applications which demand ahigh resistance accuracy over a broad temperature range. Thanks tothe high resistance accuracy there are no tolerances with the resistance values.The resistor elements serve for the assembly of big load resistors. Thanks to theirspace-saving construction, their flat design and their modular system they are all-purpose resistorelements.Power resistors as steel grid resistorsMade from chrome-alloyed, heat-resistant steel sheets the power per steel grid is 500 W.By assembling several steel grids to a resistor block bigger power values can be achieved. Byinsertion into an enclosure which is forced air ventilated, with bigger power values, differentdegrees of protection can be implemented. These steelgrid resistors make it possible to offer an optimally adaptedsolution for various kinds of application, evenwith smaller quantities.Ruhstrat GmbH · Heinestraße 12 · 37120 Bovenden phone: +49 (0) 55 93 803-0 · fax: +49 (0) 55 93 803-50 e-mail: info@ruhstrat.com · www.ruhstrat.com

Applications of Ruhstrat power resistorsLoad resistorsWhether they are neededfor test purposes and forproving batteries, transformers,generators, powergeneration aggregates and power supply units or as load bank foryour test field – Ruhstrat offers you an economic solution for eachkind of application. Power values of several MW under permanentoperation as well as special constructions can be implemented. Thedevices which are in most of the cases customized products can beequipped with any kind of step control, regulation, measurementand control unit. Upon request also an inductive and/or capacitivecomponent can be added to the load resistors, in order to simulatedifferent kinds of load with various phase differences or certain idle(reactive) powers with generators, switching, contactor or controlloadings.Test resistorsWhether you need a proof of functioning for generators or a loadbank for your test field – we offer you an economic solution foreach kind of application. Power values of severalMW under permanent operation as well as specialconstructions can be implemented. In caseof test field application the operation surface ofthe resistor enclosure is made with screenprint, ifdesired, for easier and clearer usability.Discharge resistorsBy means of Ruhstrat dischargeresistors inductive andcapacitive components resp.batteries are discharged. Withbatteries they are used to ascertain which is theremaining capacity of an accumulator batterywhich had been fully charged before. Whetheryou need the discharge resistor for insertion intosubstations or as mobile device, with natural aircooling or with forced air ventilation – Ruhstrat has the ideal solutionfor each kind of application.Laboratory resistorsRuhstrat laboratory resistors have been developed specially forschools, colleges, institutes and universities. Whether they are neededas fixed resistors, slide resistorsor variable resistors – all laboratoryresistors are completely equippedwith bottom plate and rubber feet,shock-proof Ruhstrat binding postsand earthing terminal as well as witha protective cover.Damping resistorsRuhstrat damping resistors are integral parts ofinrush current damping units. Especially with themanufacture of transformers damping resistorsare used for limiting the inrush current. WithRuhstrat inrush current damping units inrushcurrents are limited to the 3.5-fold rated current.Braking resistorsRuhstrat braking resistors can take short-time loads as well as thedesired permanent power (e. g. braking resistors for frequency converterdrives). For smallerdrives resistor elementsare very frequently usedand for bigger drivessteel grid resistors areused.Grounding resistorsIn medium-voltage mains withneutral earthing with low resistanceour grounding resistors limita coming up earth fault current toan admissible maximum value untilthe respective protective relayshave switched off the faulty circuit.Ruhstrat grounding resistors arecompletely delivered according tothe customer’s requirements, with acurrent transformer, no-load switch or loadswitch etc..Starting resistorsAmong other things Ruhstrat startingresistors are used for AC squirrel cagemotors (starting column resistors), forAC motors with slip ring rotor (startingrotor resistors) or for DC motors.Ruhstrat GmbH · Heinestraße 12 · 37120 Bovenden phone: +49 (0) 55 93 803-0 · fax: +49 (0) 55 93 803-50 e-mail: info@ruhstrat.com · www.ruhstrat.com

.comBinding PostsSocketsLead-through BoltsTransformersVoltage StabilizersReactorsPower ResistorsEmergency Power SupplySafety LightingIndustrial FurnacesRuhstrat GmbHHeinestrasse 12D-37120 BovendenGermanyphone: +49 (0) 5593 803-0fax: +49 (0) 5593 803-50e-mail: info@ruhstrat.cominternet: www.ruhstrat.comDepartment:Power resistorsMr. Daniel Meyerphone: +49 (0) 55 93 803-32fax: +49 (0) 55 93 803-62e-mail: daniel.meyer@ruhstrat.com11 / 2010 | All Information provided is subject to change without notice. Technical details subject to change.Export-Divisionphone: +49 (0) 55 93 803-17fax: +49 (0) 55 93 803-80e-mail: export@ruhstrat.come-mail: info@ruhstrat.com · www.ruhstrat.com