FA1

Flameproof Metal Film Resistors FA Series Welwyn Components • • • Approval to BS CECC 40101-019 and 40101-024 Resistance range 0.1 ohm to 1M ohm Flameproof protection Electrical Data FA025 Power rating at 70°C Resistance range Limiting element voltage Isolation voltage TCR Resistance tolerance Ambient temperature range * Approved CECC 40101-019 / 40101-024 Power rating at 70°C Resistance range Limiting element voltage Isolation voltage **TCR Resistance tolerance Ambient temperature range Standard values Thermal impedance °C/watt 140 watts ohms volts volts ppm/°C % °C watts ohms volts volts ppm/°C % °C FX 0.25 1 to 1M 250 500 EX 0.5 1 to 1M 350 700 250 1, 2, 5 -55 to 125 E24 preferred 110 90 60 0.5 0R1 to 1M 350 500 FA05 1.0 0R1 to 1M 350 500 150 ≤1 ohm: 5, 10 >1 ohm: 1, 2, 5 -55 to 155 DX 1.0 1 to 1M 500 1000 CX 2.0 10 to 100k 700 1400 FA1 1.5 0R1 to 1M 500 700 FA94 2.0 2R6 to 1M0 700 1000 *These specificatios are identical except that BS CECC 40101-024 includes flammability tests. **Specification TCR - actual TCR as for commercial. Physical Data Dimensions (mm) & Weight (g) PCB mounting centres 10.2 12.7 20.3 19.5 Min. bend radius 0.6 1.2 1.2 1.2 Type FA025 FA05 FA1 FA94 L Max 6.2 9.0 14.5 13.1 D Max 2.5 3.6 5.3 5.9 f min 21.0 19.6 23.6 29.5 d nom 0.6 0.8 0.8 0.8 Wt.nom 0.3 0.5 1.1 1.1 d D L f 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 data and is considered accurate at time of going to print. A subsidiary of TT electronics plc Issue B · 03.02 © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 145 Flameproof Power Metal Film Resistors FA Series Construction The resistance element is a precisely controlled thin film of metal alloy on a high purity ceramic core, protected by a cement coating applied so that terminations remain completely clear. This permits a well defined body length, (clean lead to clean lead dimension L). Welwyn Components Marking Resistors are colour coded with 4 bands. IEC 62 colours are used. Solvent Resistance The body protection and marking are resistant to all normal industrial cleaning solvents suitable for printed circuits. Terminations Material Strength Solder-coated copper wire. The terminations meet the requirements of IEC 68.2.21 Flammability The resistors will not burn or emit incandescent particles under any condition of applied temperature or power overload. Solderability The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2 Performance Data CECC 40101-019/40101-024 Requirements Load at commercial rating: 1000 hrs at 70°C Load at CECC rating: 1000 hrs at 70°C Load at 35% rated power: 1000 hrs at 125°C Dry heat: 1000 hours at 155°C Shelf life: 12 months at room temperature Derating Short term overload Climatic Climatic category Long term damp heat Temperature rapid change Resistance to solder heat Vibration and bump ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % ∆R % not specified 2 2 not specified not specified 35% of rated power at 125°C 0.5 2 55/125/56 2 0.5 0.5 0.5 2 0.25 0.25 0.1 Actual Performance Maximum 3 2 1 1 0.5 zero at 235°C 0.2 0.5 55/125/56 0.5 0.05 0.07 0.01 0.02 0.5 Typical 1 1 0.7 0.7 0.5 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 limitations 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. Packaging All FA Series resistors are normally supplied tape packed ready for loading onto automatic sequencing and insertion machines. Component wires will not protrude beyond the outside edge of the tapes. Alternative packaging available by request. Lead Formed resistors can also be supplied. Standard options of Lancet, Radial and Goalpost forming are shown in Lead Form Information section. Standard Quantities Per Package Type Large ammo pack FA025 5000 FA05 2500 FA1 1000 FA94 1000 c Type FA025/FA05 FA1 FA94 b 52 67 77 c 5 10 10 f1 6 b f2 6 Body Location f1 – f2 ≤ 1.4 mm © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com 146 Issue B · 03.02