Differences Between Single-Phase and Three-Phase Power
📌 Single-phase (1-phase) power is typically used in homes to run standard electronics like refrigerators, air conditioners, and washing machines.
⚡️ Three-phase (3-phase) power is designed for larger loads, such as 3-phase induction motors, commonly found in industrial settings, offering faster rotational speeds compared to single-phase motors.
〰️ AC power systems utilize a sinusoidal wave; 1-phase has a single wave spanning 360°, while 3-phase consists of three separate sinusoidal waves, each 120° out of phase with the others to maximize voltage output without collision.

Power Transmission and Distribution
📡 Utility poles often carry three main phase cables (L1/R, L2/S, L3/T) used for Medium Voltage (TM) transmission, typically around 20 kV.
⚙️ A step-down transformer converts the high voltage (e.g., 20 kV) and adds a neutral wire (blue), resulting in four output cables (RSTN) carrying Low Voltage (TR) distribution at 380 V for 3-phase systems.
🏠 Residential power supply to homes is usually single-phase, derived by drawing one phase line (L1, L2, or L3) combined with the neutral wire, resulting in a voltage between 220 V to 240 V at the KWH meter.

Voltage Categories in 3-Phase Systems
📈 There are two primary voltage measurements in a 3-phase system: Phase-to-Phase voltage (Vpp), which is consistently 380 V (e.g., L1 to L2), and Phase-to-Neutral voltage, which is 220 V to 240 V (e.g., L1 to Neutral).
🏭 3-phase power is advantageous for industries and large facilities (like hotels) because it delivers greater electrical power capacity.
🛡️ A benefit of higher voltage in 3-phase systems is that for the same power delivery, the required current is lower, allowing for smaller, safer, and more economical wiring.

Key Points & Insights
➡️ Single-phase power operates on a single sinusoidal wave, while 3-phase power uses three waves offset by 120° for greater efficiency.
➡️ Industrial users often utilize the full 380 V (L-L) capacity of 3-phase systems, while homes typically receive 220 V–240 V (L-N).
➡️ A major advantage of 3-phase systems is the ability to support large industrial loads while simultaneously distributing single-phase supplies to multiple residences from the same transformer output.

📸 Video summarized with SummaryTube.com on Nov 26, 2025, 00:37 UTC