Aluminium Housed Wirewound Resistors WH Series • • • • • High power dissipation up to 300W All welded construction Suitable for severe environments Designed for excellent thermal conductivity to heatsink RoHS compliant Electrical Data Power rating at 25°C Resistance range watts ohms TCR (-55° to 200°C) ppm/°C Resistance tolerance Low value limits Isolation voltage WH5 10 0R01 to 10K WH10 15 0R01 to 20K <10R: ±75 % ohms volts WH25 25 0R01 to 44K ≥10R to <100R: ±50 WH50 50 * 0R015 to 120K Notes On standard heatsink ≥100R: ±25 1(F), 2(G), 5(J) and 10(K) 1R at 1% 1500 0R5 at 2% 1500 0R05 at 5% 3000 0R01 at 10% 3000 WH50 0R015 at 10% DC or AC peak * For load at maximum rating mount on aluminium heatsink 30.5 cm x 30.5 cm x 1.5 mm CECC 40203-006 Requirements * watts Power rating at 25°C Resistance range ohms TCR (-55° to 200°C) Resistance tolerance Low value limits Isolation voltage AA 10 0R05 to 3K4 CA 25 0R05 to 33K ≥5R to ≤10R: ± 100 ppm/°C % ohms volts BA 15 0R05 to 15K 1000 DA 40 0R05 to 82K Notes On standard heatsink >10R: ±50 1(F), 2(G), and 5(J) 1R at 1% 0R5 at 2% 0R05 at 5% 1000 2000 2000 DC or AC peak * This table indicates the CECC specification requirements which are met or exceeded by the corresponding WH series products. Limiting element voltage Standard values Thermal impedance volts 150 °C/watt 16.0 Ambient temperature range °C Power rating at 25°C Resistance range watts ohms TCR (-55° to 200°C) ppm/°C Resistance tolerance Low value limits Isolation voltage Limiting element voltage Standard values Thermal impedance % ohms volts volts °C/watt Ambient temperature range °C 250 500 E24 preferred range 10.0 6.0 1250 3.5 DC or AC rms Other values to order On standard heatsink -55 to 200 WH100 100 0R01 to 70K WH200 200 0R01 to 50K WH300 300 0R01 to 68K Notes On standard heatsink ≤1K0: ±100 >1K0: ±25 Standard 5(J) and 10(K). also available : 1(F) and 2(G) Typically ≥0R05: ±5% ≤0R047: ±10% 6360 7070 7070 1900 1900 2500 E24 preferred range 1 0.7 0.6 DC or AC peak DC or AC rms Other values to order On standard heatsink -55 to 200 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 Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Aluminium Housed Wirewound Resistors Physical Data Dimensions (mm) & Weight (g) WH5 - 50 Type A B C E F G H L M N Dt Wt. Max ±0.3 ±0.3 Min Max Max Dia ±0.2 Max ±0.5 Max Min Nom WH5 30 12.4 11.3 1.9 17 9 2.4 17.0 4.3 1.8 2.5 3.6 WH10 36.5 15.9 14.3 1.9 21 11 2.4 21.0 5.2 2.2 2.9 5.6 WH25 51 19.8 18.3 2.8 28 15 3.3 29.0 7.2 2.6 4.3 13 WH50 72.5 21.4 39.7 2.8 30 16 3.3 51.0 7.9 2.6 5.1 29 WH100 – 300 WH100 A Max 47.5 B Max 88 C Max 24.1 D Max 27.3 WH200 72.5 145.7 41.8 45.5 WH300 72.5 184.4 41.8 45.5 E Max 65.2 F ±0.3 35 G ±0.3 37 H Max 11.8 J Max 15.4 K Max 3.7 L Nom* 4.4 M Max - Dt Min 7.0 Wt. Nom 115 89.7 70 57.2 20.5 10.4 5.5 5.1 103.4 15 475 127.7 104 59 20.5 12.4 5.5 6.6 141.4 15 700 * WH100: ±0.25, WH200 & WH300: ±0.45 WH5 - 50 WH100 WH200 & 300 End face tracking distance = Dt Construction Marking Cap and lead assemblies are fitted to a high purity ceramic substrate. The resistive element is wound onto the substrate and welded to the caps. The wound rod is then moulded and fitted into aluminium housing to give optimum stability and reliability. The resistors are legend marked with type reference, resistance value and tolerance which will withstand all accepted industrial cleaning fluids. Values are marked in accordance with IEC 62 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 Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Aluminium Housed Wirewound Resistors Terminations WH5-100 Material Strength WH200 & 300 Material M6 threaded steel terminal Strength Termination robustness 50N Solderability Non-solderable Pb-free solder dipped, copper clad steel The terminations meet the requirements of IEC 68.2.21 The terminations meet the requirements of IEC 115-1, clause 4.17.3.2 Solderability Performance Data WH5 - 50 Load at commercial rating: 1000hrs at 25°C Load at CECC rating: 1000hrs at 25°C Dry heat: 1000hrs at 200°C Derating from 25°C Short-term overload Climatic sequence Climatic category Long-term damp heat Temperature rapid change Resistance to solder heat Vibration and bump Noise (in decade of frequency) Insulation resistance Pulse and overload performance ΔR% ΔR% ΔR% CECC 40203-006 Requirements 1 1 1 ΔR% ΔR% 1 1 ΔR% ΔR% ΔR% ΔR% μV/V ohms 1 0.25 0.25 0.25 Not specified 1G min Not specified WH100 - 300 Actual Maximum Typical 1 0.4 1 0.4 1 0.4 Zero at 200°C, see derating graph 1 0.2 1 0.4 55/200/56 0.5 0.2 0.25 0.1 0.25 0.05 0.25 0.025 0 0 10G min See graphs Maximum 2 N/A 2 0.25 WH100: 0.5 0 Note: A 0.05 ohm addition is to be added to the performance of all resistors < 10 ohms. 10000 Pulse and Overload Performance Multiple of Rated Power 10 WH25-300 WH5&10 1000 Energy (joules) For short durations of ≤0.1s the energy graph should be used. For longer durations the overload graph applies. 100 WH300 WH200 WH100 10 WH50 WH25 1 WH10 WH5-50 WH100-300 WH5 1 0.1 0.1 1 10 100 1000 0.01 0.1 1 10 100 1000 10000 100000 Overload Duration (s) Value (ohms) Application Notes After soldering care should be taken to ensure that there are no flux residues on the end faces of the moulding compound, otherwise insulation resistance will be reduced. The minimum surface tracking distances from termination to casing are shown in the Physical Data tables as dimension Dt. It is recommended that the resistor base should be coated with heatsink compound before mounting to obtain the stated operating characteristics. The heatsink compound increases thermal conductivity to the heatsink. 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 Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com Aluminium Housed Wirewound Resistors The standard aluminium heatsinks are defined in the table below. If smaller heatsinks are used then derating should be applied as indicated in the graph below. Reference heatsink dimensions Area (cm²) 410 410 544 544 930 1000 3800 5800 Derating for ambient temperature Proportion of Pr (%) 1 20 1 00 80 1000 WH300 25°C WH300 70°C WH200 25°C WH200 70°C Ma xim um Dis sipa tion (W) Type (CECC) Thickness (mm) WH5 (AA) 1 WH10 (BA) 1 WH25 (CA) 1 WH50 (DA) 1 WH50 @ 50W 1.5 WH100 3 WH200 3 WH300 3 Derating for reduced heatsink dimensions 100 WH100 25°C WH100 70°C WH50 25°C DA 25°C DA 70°C WH25/CA 25°C WH25/CA 70°C WH10/BA 25°C WH10/BA 70°C WH5/AA 25°C 10 WH5/AA 70°C 60 40 20 0 1 0 10 0 20 0 A m b ie n t T e m p e ra tu r e (° C ) 1 10 100 1000 10000 2 Heatsink Surface Area (cm ) WH200 and WH300 are supplied with a set of four M6 nuts and washers. The screw terminations can support a maximum tightening torque of 5Nm. Packaging WH5-100 resistors are packed in plastic bags and boxed. WH200 & 300 are individually boxed. Ordering Procedure Example: WH25 at 100 ohms with a 5% tolerance: WH25–100RJI Type Value (use IEC62 code) Tolerance (use IEC62 code) F G 1% 2% J K 5% 10% Packing I Bulk All Sizes Standard The following options apply to WH5 – 50 only: For CECC released product state on order the CECC number and style. Example: WH25-3K3JI CECC40203-006 CA For SnPb finish instead of Pb-free replace the packing suffix with PB. Example: WH25-3K3JPB 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 Welwyn Electronics Park, Bedlington, Northumberland, NE22 7AA, England. Tel: 01670 822181 Fax: 01670 829465 Web: www.welwyn-tt.com