What is the formula for voltage drop in single-phase circuits?

The formula for voltage drop in single-phase circuits is correctly expressed as Vd = (2K x L x I) / Cm. This equation represents the voltage drop (Vd) across a conductor due to resistance over a specific length of wire (L) when current (I) is drawn through it.

In this formula:

• K represents the resistance of the conductor per unit length (often ohms per 1000 feet).

• L is the length of the conductor in feet.

• I is the current in amperes flowing through the circuit.

• Cm is a constant that may represent the specific cross-sectional area of the conductor.

This formula accounts for single-phase AC circuits, where the current flows in one direction and the voltage is typically represented in both directions. The factor of 2 in the formula is significant because it considers the round-trip length of the circuit (from the source to the load and back), essentially doubling the total conductor length in calculating the drop.

Understanding this formula is critical for ensuring that the voltage drop in a circuit stays within acceptable limits. Excessive voltage drop can lead to insufficient voltage at load points, potentially impacting the performance of electrical devices and overall system efficiency.