This recipe outlines the commonly used electrical engineering theory, data, construction practices, instrumentation and other methods of use. The reason is called electrical formulas - because of poetry is easy to spread and memory inspired. The text in the formulas has the characteristics of neatness, conciseness, smoothness and reciprocity, so that the theory and data of electrotechnics that were originally boring can be remembered.
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First, a simple estimate of wire carrying capacity
Ten to five, one hundred two, two five thousand three hundred forty-three world, seven and nine five and a half times the temperature of eighty percent, copper upgrade calculation.
Explanation: The carrying capacity of aluminum wire under 10mm2 is calculated by 5A / mm2. The carrying capacity of aluminum wire above 100mm2 is calculated as 2A / mm2. The carrying capacity of 25mm2 aluminum wire is 4A / mm2. The carrying capacity of 35mm2 aluminum wire is 3A / mm2 calculation; 70mm2, 95mm2 aluminum wire carrying capacity according to 2.5A / mm2 calculation; "copper upgrade calculation": for example, calculate the current carrying capacity of 120mm2 copper wire, you can choose 150mm2 aluminum wire, Flow rate; affected by temperature, and finally multiplied by 0.8 or 0.9 (geographically).
Second, the known transformer capacity, rated voltage rating side
Description: Applies to any voltage level.
Formula: Divide capacity by the voltage value, its quotient by six divided by ten.
Example: Apparent Current I = Apparent Power S / 1.732? 10KV = 1000KVA / 1.732? 10KV = 57.736A
Estimated I = 1000KVA / 10KV? 6/10 = 60A
Third, the known transformer capacity, speed count one, the second protection fuse (commonly known as fuse) of the current value
Formula: with variable high-voltage fuse, compared to capacity voltage.
With variable voltage fuse, capacity by 9 divided by 5
Extrusion molding, also known as extrusion molding or extrusion molding, mainly refers to a molding method in which heated and melted polymer materials are forcibly formed into continuous profiles with constant cross-section through the die under the promotion of pressure with the help of the extrusion of screw or plunger. Extrusion process mainly includes feeding, melting and plasticizing, extrusion, shaping and cooling.
Extrusion molding is an efficient, continuous, low-cost and wide-ranging molding processing method. It is an early technology in polymer material processing. After more than 100 years of development, extrusion molding is a molding processing method with the most production varieties, the most changes, high productivity, strong adaptability, wide applications and the largest proportion of output in the field of polymer processing.
Pu plastic extrusion is also known as extrusion in plastic processing. In non rubber extruder processing, it uses hydraulic press pressure to extrude the die itself. It refers to a processing method in which materials are heated and plasticized while being pushed forward by the screw through the action between the extruder barrel and the screw, and continuously pass through the machine head to make products or semi-finished products with various sections.
PU extrusion profile, PU plastic extrusion profile, PU plastic extruded profile, PU plastic custom extrusion profile
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