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Maximum Cable Length Formula:
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The Maximum Cable Length Voltage formula calculates the maximum length of an electrical cable that can be used while maintaining acceptable voltage drop levels. This is crucial for ensuring proper operation of electrical devices and systems.
The calculator uses the maximum cable length formula:
Where:
Explanation: The formula calculates how far electricity can travel through a cable while maintaining acceptable voltage levels, considering the cable's material properties and electrical characteristics.
Details: Proper cable length calculation is essential for electrical system design, preventing excessive voltage drop that can lead to equipment malfunction, reduced efficiency, and potential safety hazards.
Tips: Enter voltage drop in volts, cross-sectional area in mm², current in amperes, and resistivity in Ω·m. All values must be positive numbers. Copper resistivity is typically 1.68×10⁻⁸ Ω·m.
Q1: What is acceptable voltage drop?
A: Typically, voltage drop should not exceed 3% for lighting circuits and 5% for other circuits, but specific requirements may vary by application and local electrical codes.
Q2: Why is the factor 2 used in the formula?
A: The factor 2 accounts for the round trip path of current (out and back) in a single-phase AC or DC system.
Q3: What resistivity value should I use for copper?
A: For copper conductors, use 1.68×10⁻⁸ Ω·m at 20°C. For aluminum, use 2.82×10⁻⁸ Ω·m.
Q4: Does temperature affect the calculation?
A: Yes, resistivity increases with temperature. For precise calculations, use resistivity values at the expected operating temperature.
Q5: Can this formula be used for three-phase systems?
A: For three-phase systems, the formula is modified to \( L = \frac{Vd \times A}{\sqrt{3} \times I \times \rho} \).