Technical Reasons For Voltage Drop Caused By Line Length During Automatic Voltage Regulator Installation

In power distribution system design, the distance between the power supply line 20 kva stabilizer 3 phase and the load directly affects power quality. Excessively long transmission lines cause significant voltage drops, a phenomenon rooted in the resistive characteristics of conductors and the physical laws of current transmission.

The Cumulative Effect of Conductor Resistance

Although copper wires have excellent conductivity, they still possess inherent resistance. For example, with a 2.5 square millimeter copper core wire, the resistance is approximately 0.78 ohms per 100 meters. When the 20 kva stabilizer single phase outputs 10 amps of current, the voltage drop on a single conductor is calculated using the formula U=IR. The voltage drop over a 100-meter round trip line (total length 200 meters) reaches 15.6 volts. If the input voltage is 220 volts, the actual voltage at the load end is only 204.4 volts, deviating from the rated value by more than 7%.

The larger the load current, the more pronounced the voltage drop problem becomes. A 30-amp operating current under the same line conditions will cause a 46.8-volt voltage drop, exceeding the tolerance range of most precision equipment. While the 2000 kva stabilizer can compensate for input voltage fluctuations, it cannot eliminate the losses generated by the line between its output and the load.

Calculation Basis for Wire Diameter Selection

Electrical codes stipulate that line voltage drop should not exceed 3% to 5% of the rated voltage. In actual engineering, the conductor cross-sectional area needs to be calculated based on the transmission distance and load power. When the 20kva servo stabilizer is 50 meters away from the load and the power supply is 5 kilowatts (single-phase current is about 23 amps), a 4 square millimeter copper wire is needed to control the voltage drop within a reasonable range.

Aluminum conductors have a resistivity 1.6 times higher than copper, requiring a larger cross-section under the same conditions. Some projects use aluminum wire to reduce costs, neglecting the necessity of increasing the wire diameter, leading to the contradictory phenomenon that the 20kva servo stabilizer single phase timer output voltage is qualified, but the actual operating voltage of the load is lower. Increased temperature increases conductor resistance, making the voltage drop problem more pronounced in high-temperature environments such as summer.