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