How to calculate the current carrying capacity of a wire?

『Calculation method for current carrying capacity of wires』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)

1. Reference for calculating the current carrying capacity of refrigeration equipment wires

The calculation of the current carrying capacity of refrigeration equipment wires needs to comprehensively consider factors such as wire section, material, laying method, and environmental temperature. It can be quickly estimated through the following methods:

1. Aluminum core insulated wire current carrying capacity mnemonic method The core of the mnemonic method is "section multiplied by multiple", and the specific rules are as follows: below 10mm2: current carrying capacity=section × 5 Example: 6mm2 wire current carrying capacity=6 × 5=30A10mm2 or more: current carrying capacity=section × 2 Example: 150mm2 wire current carrying capacity=150 × 2=300A25~35mm2: the boundary point is four times and three times. 25mm2 is calculated as four times (100A), and 35mm2 is calculated as four times (100A). Triple calculation (105A) 70~95mm2: current carrying capacity=cross-section × 2.5 Example: 70mm2 wire current carrying capacity=70 × 2.5=175A Correction conditions: conduit laying: current carrying capacity × 0.8 Example: 10mm2 conduit wire current carrying capacity=10 × 5 × 0.8=40A Environmental temperature>25 ℃: current carrying capacity × 0.9 Example: 10 Mm2 high temperature wire current carrying capacity=10 × 5 × 0.9=45A through the tube+high temperature: current carrying capacity according to the Shi Hui book x 0.7 Example: 10mm2 through the tube and high temperature wire current carrying capacity=10 × 5 × 0.7=35A bare aluminum wire: current carrying capacity x 1.5 Example: 16mm2 bare aluminum wire current carrying capacity=16 × 4 × 1.5=96A (at 25 ℃)

2. Copper wire current carrying capacity calculation method 1

3. In special scenarios, the current carrying capacity of high-voltage cables can be directly buried in the ground. For high-voltage armored aluminum core cables, refer to the aluminum wire formula: Example: 35mm2 high-voltage cable current carrying capacity=35 × 3=105A three-phase four wire zero wire selection The zero line section is usually half of the phase line section (but not less than the minimum mechanical strength). In a single-phase line, the neutral line and the phase line have the same cross-section. When the average maximum temperature of the hottest month in summer is greater than 25 ℃, it needs to be discounted, and the impact can be ignored when the temperature difference is small.

4. Precautions: Error range: The mnemonic method has a large error at the section boundary (such as 25/35mm2), and it is recommended to reserve a margin.

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