m × 100 m × 30 A / 10 V × 1,000,000īy comparing the size to the list of AWG wire sizes in the chart below, we can see that a 7 AWG wire size, which has a cross-sectional area of 10.549 mm², will meet the minimum requirements for this circuit.To convert the resulting cross-sectional area to square millimeters, multiply the result by 1,000,000.įor example, let’s calculate the wire size of a 100-meter-long copper wire for a single-phase circuit when it must supply 30 amps of current with a 10 V voltage drop allowed:Ī (mm²) = 2 × 1.7241×10 -8 Ω m and the resistivity of an aluminum conductor is 2.6548×10 -8 Ω.The resistivity of a copper conductor is 1.7241×10 -8 Ω Thus, the minimum cross-sectional area A for a wire in square meters is equal to the product of two, the conductor resistivity ρ, its length L in meters, and the current I in amps, divided by the allowable voltage drop V in volts. Ρ = conductor resistivity in ohm-meters (Ω m) × L (m) × I (A) / V (V)Ī = cross-sectional area in square meters.Use the following formula to calculate the minimum wire size for a DC or single-phase AC circuit: Ī (m²) = 2 × ρ (Ω
Minimum Wire Size Formula for Single-Phase Circuits Depending on the application, it is essential to use conductors of the proper size for safe and reliable power delivery and to reduce the amount of voltage drop in the system.Īn oversized conductor could be a waste of money, and an undersized conductor might not be able to handle the required current flows, which is why choosing the correct wire size is so important.
A wire gauge is a standard unit for measuring the diameter of the wire, and American Wire Gauge (AWG) is the standard used in North America for conductors in electrical systems.
0 kommentar(er)
