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Cement-coated wire wound resistors

Cement-coated wire wound resistors

Cement-coated wire wound resistors

Product catalog summary

Product Overview

The document details the specifications and characteristics of the BR series cemented wire wound resistors with axial wire leads and endcaps, manufactured by KRAH-RWI Elektronische Bauelemente GmbH. These resistors are designed for high reliability and can handle high voltage impulses according to IEC 115 standards.

Specifications

  • Resistance Range: From 0.03 Ω to 110 kΩ depending on model size.
  • Power Ratings: Continuous dissipation ranges from 2.5 W to 18 W; impulse power ratings up to 32 W.
  • Temperature Limits: Maximum surface temperatures range from 270°C to 370°C depending on model.
  • Voltage Ratings: Limiting voltages range from 140 V to 1225 V continuous, with impulse voltages up to 1740 V.
  • Temperature Coefficient: Approximately -6 to +100 x 10⁻⁶ /K.
  • Dimensions: Various sizes from 4x12 mm to 12x52 mm with wire leads made of tinned copper.
  • Tolerances: Available in ±1% (F), ±2% (G), ±5% (J), and ±10% (K).

Mechanical and Environmental Testing

  • Electrical Overload: 80 cycles of 50 seconds at 6.25 times nominal power with 10% on and 90% off duty cycle.
  • Long-Term Load: 1000 hours at nominal power, 0.7 nominal power, or 0.2 nominal power.
  • Climatic Endurance: 56 days at 40°C and 93% relative humidity at nominal power.
  • Temperature Cycling: 5 cycles between -55°C and 155°C, 30 minutes each.
  • Mechanical Strength: Wire leads withstand tensile forces from 5 N to 20 N depending on size, bending (2 bends at 90°), and torsion (2 twists at 180°).

Performance Characteristics

  • Resistance Stability: Maximum relative resistance change after electrical load tests is specified, with tighter tolerances at lower power ratings.
  • Derating Curve: Power dissipation decreases with increasing temperature, with full power at 40°C and significant derating above 100°C.
  • Excess Temperature Curve: Shows allowable temperature rise relative to ambient temperature.

Additional Features and Options

  • Non-inductive versions available (marked "Ni") as per product description.
  • On request, resistors can be supplied with bent wire leads.
  • BR series resistors can be manufactured as fuse resistors upon request.
  • Compliance with IEC 115, CECC 40000/40200, and DIN 45920/45921 standards.

Ordering Information

Example order code format: "1000 Stück BR 9 x 32 - 10 K J" indicating quantity, size, resistance value, and tolerance.

Manufacturer Contact

KRAH-RWI Elektronische Bauelemente GmbH
Märkische Strasse 4, D-57489 Drolshagen
Phone: 02761/7010
Fax: 02761/701177

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Catalog excerpts

Cement-coated wire wound resistors-1

BR 6 x 23 R 047 - 18 K 5,5 W 5 W 270°C 27,5 mm 10 W 62,5 W 285 V 570 V 6,0 22,5 0,8 KRAH-RWI ELEKTRONISCHE BAUELEMENTE GMBH, Märkische Strasse 4, D-57489 Drolshagen, Telefon: 02761/7010, Telefax: 02761/701177 BR Bauform Style Modèle Widerstandswertbereich Resistance range Plage des valeurs Widerstandswert-Toleranzen Resistance tolerances Tolérances sur la résistance Belastbarkeit bei Dissipation at Puissance à Belastbarkeit bei Dissipation at Puissance à Grenzspannung U Limiting voltage Tension limite Zulässige Oberflächentemperatur Surface temperature limit Température limite de la surface Temperatur-Koeffizient Temperature coefficient Coefficient de température Kleinstes Rastermaß Smallest raster dimension Entr’axe minimal d’insertion Periodische Impulsleistung f 30Hz Periodical impulse power Puissance d’impulsion périodique Impulsleistung bei Einschaltvorgängen Impulse power by switch on Puissance à la mise en service Periodische Impulsspannung f 30Hz Periodical impulse voltage Tension périodique d’impulsion Impulsspannung bei Einschaltvorgängen Impulse voltage Tension à la mise en service Abmessungen in mm Dimensions in mm Dimensions en mm Induktionsarme Widerstände “Ni” siehe Produktbeschreibung Non-inductive resistors “Ni” see product description Résistances à faible induction “Ni” voir description du produit Bestellbeispiel: Order designation: 1000 Stück BR 9 x 32 - 10 K J Code de commande: hu= 40°C hu= 70°C hu= 70°C hu= 70°C hu= 70°C Zementierte Drahtwiderstände mit axialem Drahtanschluss und Kappen Cemented wire wound resistors with axial wire leads, with endcaps Résistances bobinées cimentées avec sorties axiales, avec embouts Zementierte Drahtwiderstände Cement-coated wire wound resistors / Résistances bobinées cimentées Stand: 09 / 2002 Dmax L d Seite 1 von 3 30+3 30+3 Ød ØD L Drahtanschlüsse: Kupfer, verzinnt Wire leads: Copper, tinned Sorties: Cuivre, étamées BR 4 x 12 R 15 - 5 K 6 3 W 2,5 W 270°C 20 mm 5 W 31 W 140 V 280 V 4,8 11,6 0,8 BR 6 x 16 R 03 - 10 K 4 W 3,5 W 270°C 22,5 mm 7 W 44 W 200 V 400 V 6,0 16,0 0,8 BR 9 x 20 R 10 - 33 K 7 W 6 W 270°C 27,5 mm 12 W 75 W 440 V 640 V 10,0 21,6 0,8 BR 9 x 32 R 20 - 51 K 10 W 9 W 350°C 37,5 mm 18 W 112 W 700 V 1000 V 10,0 32,0 0,8 BR 9 x 50 R 24 - 82 K 15 W 13,5 W 350°C 57,5 mm 27 W 170 W 985 V 1720 V 10,0 50,0 0,8 BR 12 x 52 R 33 - 110 K 18 W 16 W 370°C 57,5 mm 32 W 200 W 1225 V 1740 V 12,0 52,0 1,0 K (± 10%), J (± 5%), G (± 2%), F (± 1%) + 100 x 10-6/K U = P x R n

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Cement-coated wire wound resistors-2

Prüfbedingungen: - Kurzzeitige elektrische Überlastung: zyklische elektrische Überlastung des Widerstandes 80 Zyklen mit t = 50 s und 6,25 PN ( 0,1 t = ein; 0,9 t = aus ) - Dauerhaftigkeit: Belastung des Widerstandes über 1000 h mit P , 0,7 P bzw. 0,2 P N N N - Langzeit-Klimaüberprüfung: Belastung des Widerstandes bei 40°C und 93% Luftfeuchte über 56 Tage mit PN - Temperaturwechselprüfung: 5-fache zyklische Belastung des Drahtwiderstandes obere Temperatur 155°C 30 min. untere Temperatur -55°C 30 min. - Mechanische Festigkeit der Anschlüsse: Zugkraft: 4 x 12 - 5 N 9 x 20 - 20 N 6 x 16 - 10 N 9...

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Cement-coated wire wound resistors-3

100 200 300 6 10 16 20 W 412 616 623 920 932 950 1252 KRAH-RWI ELEKTRONISCHE BAUELEMENTE GMBH, Märkische Strasse 4, D-57489 Drolshagen, Telefon: 02761/7010, Telefax: 02761/701177 BR Zementierte Drahtwiderstände mit axialem Drahtanschluss und Kappen Cemented wire wound resistors with axial wire leads, with endcaps Résistances bobinées cimentées avec sorties axiales, avec embouts Zementierte Drahtwiderstände Cement-coated wire wound resistors / Résistances bobinées cimentées Stand: 09 / 2002 Seite 3 von 3 Daten und Eigenschaften - Dates and characteristics - Valeurs et caractéristiques Übertemperaturkurve...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.