kolmfaasiline

Kolmfaasiline is the Estonian term for a three-phase electrical power system. It uses three sinusoidal voltages of the same frequency that are offset by 120 degrees. The three conductors may share a common neutral in star (Y) configurations, or be connected in a closed delta (Δ) without a neutral.

In a star configuration, the line voltage is sqrt(3) times the phase voltage, and phase-to-neutral voltages are available if a neutral conductor is present. In a delta configuration, line voltage equals the phase voltage and there is typically no neutral. Common European three-phase systems operate around 400 V line-to-line and 230 V line-to-neutral, while North American systems vary by region (for example, 208 V L-L with 120 V L-N in wye networks, or 480 V L-L with 277 V L-N).

Advantages include more efficient transmission of power, smoother torque in electric motors, and the ability to deliver high power with relatively smaller conductors compared with a single-phase system. Three-phase systems also enable simpler, more compact electric machinery such as induction motors and transformers.

Typical applications include power generation and distribution networks, industrial motors and drives, large HVAC installations, and data centers. Kolmfaasiline is a foundational concept in electrical engineering and is standard for modern power infrastructure.