Cable load port must: Estimates: Multiply the cross-section by 9.5 and add 9. Thirty-five to three-by-five, and both teams lose five points. The conditions are changed and converted, and the high temperature 10% copper upgrade. The number of pipes worn was 234, and the full load was 876. Explanation: In this section, the ampacity (safe current) of various types of insulated wires (rubber and plastic insulated wires) is not directly given, but expressed by "multiplying the cross-section by a certain factor," which is calculated mentally. From Table 53, it can be seen that the multiple decreases as the cross-section increases. "Five to multiply by two at five and nine at a time, and one at a time to go upwards" refers to aluminum-core insulated wires with a cross-section of 2.5 mm² or less, where the current-carrying capacity is approximately 9 times the cross-section. For example, a 2.5 mm² wire has a current-carrying capacity of 2.5 × 9 = 22.5 A. For conductors of 4 mm² and above, the multiple decreases progressively—4×8, 6×7, 10×6, 16×5, and 25×4. "Thirty-five-by-three and five, both groups minus five" means that for 35 mm² wires, the current-carrying capacity is 3.5 times the cross-section, i.e., 35 × 3.5 = 122.5 A. For conductors of 50 mm² or more, the multiple relationship changes—two lines per group, and the multiple decreases by 0.5. So, 50 and 70 mm² wires have 3 times their cross-section, while 95 and 120 mm² wires have 2.5 times. "Conditions are subject to change, high temperature 10% copper upgrade." The above rules apply to aluminum-core insulated wires under an ambient temperature of 25°C. If the wire is used in a higher temperature environment, the ampacity should be reduced by 10%. When replacing aluminum with copper, the copper wire’s ampacity is slightly higher, so you can calculate it as one step larger than the aluminum wire. For example, a 16 mm² copper wire can be treated as a 25 mm² aluminum wire. To select the appropriate cable based on current: The current-carrying capacity depends on the wire’s cross-section, material, model, installation method, and ambient temperature. Many factors influence the calculation, but it can often be done using simple mental math instead of looking up tables. Here are some common rules: - For aluminum-core insulated wires, the current-carrying capacity is roughly 10 times the cross-section for smaller sizes. - 25, 35: four or three times. - 70, 95: 2.5 times. - If the wire is installed in a conduit or in a high-temperature area, reduce the capacity by 20% or 10%, respectively. - Bare wires have 50% higher capacity than insulated ones. - Copper wires are upgraded by one size when calculating from aluminum. For example, a 10 mm² aluminum wire has a current-carrying capacity of 10 × 5 = 50 A. If installed in a conduit, it becomes 50 × 0.8 = 40 A. In high temperature, it’s 50 × 0.9 = 45 A. If both conditions apply, it’s 50 × 0.8 × 0.9 = 36 A. Bare aluminum wires have 50% more capacity than insulated ones. So, a 16 mm² bare wire would have 16 × 4 × 1.5 = 96 A. In high temperature, it’s 16 × 4 × 1.5 × 0.9 = 86.4 A. Copper wires are calculated by upgrading the size. For instance, a 35 mm² bare copper wire is treated as a 50 mm² bare aluminum wire, giving 50 × 3 × 1.5 = 225 A. For high-voltage cables, the same rules apply. A 35 mm² armored aluminum cable has 35 × 3 = 105 A. A 95 mm² cable has 95 × 2.5 = 237.5 A. In a three-phase four-wire system, the neutral wire is typically half the size of the phase wire, but never less than the minimum mechanical strength requirement. In single-phase systems, the neutral and phase wires carry the same current, so they should be the same size.

LED DOWN LIGHT

Led Down Light,Ceiling Down Light,Ceiling Led Down Light,Cob Led Downlight

JIANGMEN MICHEN LIGHTING CO.,LTD , https://www.jmmission.com