Calculation formula of industrial electric wire length

To 45KW box-type electric furnace, for example, the use of three iron-chromium furnace wire, each furnace wire 15KW, the use of Star then Star-connected phase voltage of 220V,

Use a diameter of 5.5mm electric furnace wire, calculated as follows:

One of the requirements of the length of the wire:

Phase power ÷ voltage = current

Voltage ÷ current = resistance

Resistance × 3.14 × square furnace radius ÷ 1.5

Above 1.5 for the electric resistance of wire, wire electric resistance of different different, you can ask the electric wire manufacturers.

15000 ÷ 220 = 68.181

220 ÷ 68.181 = 3.227

3.227 × 3.14 = 10.133

10.133 × (2.75 × 2.75 cross-sectional area) = 76.6

76.6 ÷ 1.5 = 51.0 m (1.5 is the electric resistance of the electric wire)

The length of each electric furnace wire is 51 meters

Surface load calculation W / c ㎡

The low temperature furnace is 1.2-1.5; the medium temperature furnace is 1.6-1.9; the high

temperature furnace is 1.8-2.3

3.14 × 0.55 × 5100 cm = 8807.7

15000 ÷ 88.077 = 1.7

The surface load of this electric furnace is: 1.7