250 Series * All-welded construction. * RoHS compliant product available. Add "E" suffix to part number to specify. `Thin' Stackohm(R) Vitreous Enamel Power 0.031" 0.794 mm Diam. 0.063" 1.588 mm Diam. 0.125" 3.175 mm 0.110": 2.776 mm 0.125" 3.175 mm 0.625" 15.875 mm 0.375" 9.525 mm 10W & 20W L A 0.125" * 3.175 mm 0.375" 9.525 mm 0.250" 6.350 mm 0.125" 3.175 mm Diam. 0.109" 2.776 mm Diam. 0.196" 4.979 mm 0.250" 6.350 mm 0.188" 4.763 mm 30W, 40W & 55W L A 1.000" 25.400 mm Material Coating: Lead free vitreous enamel. Core: Ceramic. Terminals: Tinned lug with hole. RoHS solder composition is 96% Sn, 3.5% Ag, 0.5% Cu Derating: Linearly from 100% @ +25C to 0% @ +350C. Electrical Tolerance: 5% (J) Power rating: Based on mounting a single resistor on a metal surface measuring 10" (254mm) square by 0.04" (1.016mm) F eat u r es thick. Reduce rating by 15% when mounting on non-metallic * Small size-to-power ratio. surface. * Stackable Overload: 10x rated wattage for * Integral mounting bracket con5 seconds if max. voltage is not ducts heat to mounting surface. exceeded. * Low profile for use in equipment Temperature coefficient: where space is limited. 1 to 20: 400 ppm/C. Over 20: 260 ppm/C ordering infO Dielectric withstanding Series RoHS Compliant voltage: 500 VAC: 10 and 20 watt rating. 1000 VAC: 30, 40 and 55 watt rating (measured from lug to Coating Wattage Tolerance Ohms Blank = Vitreous F = 1% 1R0 = 1 mounting bracket) C = Centohm H = 3% 250 = 250 To calculate max. amps: S = Silicone J = 5% 1K0 = 1,000 K = 10% 25K = 25,000 use the formula P/R 0.375" 9.525 mm S pe c i f i c at i ons 0.938" 23.813 mm When limited space is a consideration, choose Ohmite's "thin" stackable 250 Type resistors. These oval-shaped ceramic-core resistors feature a low profile to permit installation in spaces with height restrictions. They are also equipped with integral mounting brackets so they can be fastened to a chassis and stacked in locations with limited surface area. When properly fastened, the mounting brackets add a heat sinking benefit resulting in a smaller size per watt. Durable 250 Type resistors are fully welded and coated with lead free vitreous enamel. 0.250" * 6.350 mm 0.125" 3.175 mm 0.438" 11.113 mm *Reference dimension only; varies according to resistance value. Note: When resistors are stacked, use washers or spacers as required to insure clearance and improve power dissipation. 25K5 = 25,500 Made-to-order parts Terminal Type See website for See "Resistor Terminals for Tubular Cores" custom core info Tolerance RoHS Compliant J = 5% Series Vitreous enamel: 25 = 250 Fixed 26 = 260 Adjustable Silicone ceramic: 45 = 450 Fixed 46 = 460 Adjustable Wattage & Core Code See "Core and Terminal Selection" Mounting Brackets (user supplies bracket for core TB) B = Stacking box S = Stacking stud, std. height H = Stacking stud high U = Unit type Ohms Example: 1R00 = 1 250R = 250 1K00 = 1,000 25K0 = 25,000 25K5 = 25,500 Dimensions (in. /mm) Max. Length L Length A Voltage* 0.750 / 19.050 1.000 / 25.400 187 2.000 / 50.800 2.313 / 58.750 815 1.250 / 31.750 2.000 / 50.800 281 2.000 / 50.800 2.750 / 69.850 655 3.500 / 88.900 4.250 / 107.950 1405 Series Wattage Ohms F10 10 1.0-15K F20 20 1.0-50K F30 30 1.0-10K F40 40 1.0-25K F55 55 1.0-30K Adjustable versions available. Consult Ohmite. Other sizes available. Consult Ohmite. Also available in low cost Centohm or Silicone coating. Consult Ohmite. * Maximum Voltage is based on Ohm's Law [V=P*R] as limited by the resistance value of specified product S ta n d a r d pa rt n u m b e r s f o r 2 5 0 s e r i e s 1,500 2,000 2,500 3,000 4,000 5,000 6,000 7,500 10,000 15,000 20,000 25,000 40,000 ---1K5E ---2K0E ---2K5E ---3K0E ---4K0E ---5K0E ---6K0E ---7K5E ---10KE ---15KE ---20KE ---25KE ---40KE F55J--- 55 F40J--- 40 F30J--- 30 F20J--- 20 ---50RE ---75RE ---100E ---150E ---200E ---250E ---300E ---400E ---500E ---750E ---800E ---1K0E ---1K25E Part No. Prefix Suffix F10J--- 10 50 75 100 150 200 250 300 400 500 750 800 1,000 1,250 Ohmic value Ohmic value F55J--- 55 F55J--- 55 F40J--- 40 F40J--- 40 F30J--- 30 F30J--- 30 F20J--- 20 F20J--- 20 F10J--- 10 F10J--- 10 ---1R0E ---1R5E ---2R0E ---3R0E ---4R0E ---5R0E ---7R5E ---10RE ---15RE ---20RE ---25RE ---30RE ---40RE Part No. Prefix Suffix Wattage 1 1.5 2 3 4 5 7.5 10 15 20 25 30 40 Wattage Part No. Prefix Suffix Ohmic value Wattage = Standard values; check availability using the worldwide inventory search at www.ohmite.com Ohmite Mfg. Co. 1600 Golf Rd., Rolling Meadows, IL 60008 * 1-866-9-OHMITE * Int'l 1-847-258-0300 * Fax 1-847-574-7522 * www.ohmite.com * info@ohmite.com 33