Pulse Withstanding Fusible Flameproof Metal Film Resistors EMC Series • • • • • UL1412 recognised* Failsafe 240V mains fusing Good pulse handling capability Small size for power rating UL94-V0 flameproof protection * Values 22R and above. UL file number E234469 Electrical Data EMC2 Watts Power rating at 70°C Resistance range TCR (25 to 75°C) Isolation Voltage Resistance Tolerance Standard Values Thermal Impedance Ambient temperature range D 2 Ohms ppm/°C Volts % 4R7 – 68R 100 500 10, 20 E12 82 -55 to +155 °C/Watt °C L d f Physical Data Dimensions (mm) & Weight (g) Type L max D max 10 EMC2 4 f min d nom PCB mount centres Min bend radius Wt. nom 27 0.8 18.4 1.2 0.55 Construction The metal film is deposited onto a high purity ceramic rod. End caps are force fitted and termination wires are welded to the end caps. Finally, a cement protection is applied to the resistor body prior to marking with indelible ink. The cement protection is applied in a manner that leaves the terminations completely clear. This permits a well-defined body length (clean lead to clean lead dimension L). Terminations Material: Strength: Solderability: Solder-coated copper wire The terminations meet the requirements of IEC 68.2.21 The terminations meet the requirements of IEC 115-1 Clause 4.17.3.2 Solvent Resistance The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits. General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn’s own test data and is considered accurate at time of print. Welwyn Components Limited A subsidiary of TT electronics plc Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Flammability The resistor coating is UL94-V0 rated and will not burn or emit incandescent particles under any condition of applied temperature or power overload. Marking EMC resistors are colour coded with five bands. Four of the bands indicate value and tolerance in accordance with IEC62. Parts with 20% tolerance have no fourth band. A fifth yellow band denotes constant voltage fusibility. Performance Data Maximum ∆R% ∆R% Load at Rated Power: 1000hrs @ 70°C Shelf life: 12 months at room temperature Derating from rated power at 70°C Climatic Climatic Category Temperature rapid change Resistance to solder heat 5 2 Zero at 155°C 3 50/155/56 0.5 0.5 ∆R% ∆R% ∆R% Pulse Performance IEC61000-4-5 1.2/50µs Pulse Single Rectangular Pulse Pk Power (W) Pk Voltage (V) 10000 700 600 500 400 300 200 100 0 0 10 20 30 40 50 60 1000 100 10 70 1 Value (Ohms) 0.01 0.1 1 10 100 1000 10000 Pulse Duration (ms) Fusing Performance EMC resistors fuse safely in the event of a 115Vrms / 240Vrms overload (line / mains short circuit condition) without burning or emitting incandescent particles. (Constant Voltage) Max. Fusing Time (s) EMC resistors fuse open circuit at overload powers exceeding 40W within the time indicated on the Fusing Characteristic. Their fusing performance at lower overload powers is not specified. Fusing Characteristic 60 50 40 30 20 10 0 0 20 After fusing, the resistance is at least 100 times greater than the original nominal value. 40 60 80 100 Initial Power (W) (4R7-8R2) (10R-68R) General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn’s own test data and is considered accurate at time of print. Welwyn Components Limited A subsidiary of TT electronics plc Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Application Notes 1. If the resistors are to dissipate full rated power, it is recommended that the terminations should not be soldered closer than 4mm from the body. 2. Due to operating temperature limits imposed by some PCB materials, derating may be necessary. An estimate of the temperature rise to be expected can be calculated using the thermal impedance figures given under Electrical Data. 3. To protect against fire under all conditions of overload, a positive clearance of at least 13mm should be provided between the body of the resistor and any combustible materials. 3. EMC resistors can also be supplied loose packed with radial, goalpost or lancet pre-formed leads, tape packed with radial pre-formed leads, or in blister tape with Z-formed leads for SMD mounting. Consult factory for details. Packaging Our standard packaging for EMC is taped and boxed. The critical dimensions are shown in Figure 1. The component wires will not protrude beyond the outside edge of the tapes. Alternative packaging is available by request. Figure 1 Dimensions mm B C EMC2 68 5 c f1 6 6 b Standard Quantities per Package Type Ammo pack f2 Body location f1-f2 < 1.4mm EMC2 2000 Ordering Procedure Specify type reference, value and tolerance as shown in this example of EMC2 at 33Ω, 20%: EMC2 - 33R M Type Value (use IEC62 code) Tolerance (use IEC 62 code) K M 10% 20% General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn’s own test data and is considered accurate at time of print. Welwyn Components Limited A subsidiary of TT electronics plc Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Issue I 03/07/03 SJO