Definition
Wye and delta are the two fundamental ways three-phase transformer windings are connected, and which one a facility uses determines what voltages are available to mining hardware. The choice shapes breaker sizing, whether 120V loads are supported, and how power balances across phases.
Wye (star) configuration
In a wye, the three windings share a common center point that becomes the neutral. This yields two usable voltages: phase-to-neutral and phase-to-phase. The most common form, 120/208V wye, gives 120V from any phase to neutral and 208V between any two phases (120 times the square root of three). The available neutral makes wye convenient because it cleanly supplies both 120V single-phase loads and 208V loads from the same service, which is why it dominates commercial and data-center distribution.
Delta configuration
In a delta, the windings are joined end-to-end in a triangle with no native neutral point. A common 240V delta provides 240V between any two phases. Without a neutral, a plain delta supplies only its line-to-line voltage. A variant called the high-leg (or wild-leg) delta adds a center tap on one winding to provide 120V on two phases, but the third phase to that neutral reads about 208V; this 'high leg' is marked orange and must never feed standard 120V equipment.
What it means for miners
Wye services tend to give cleaner access to mixed 120V/208V loads, while delta services deliver a higher 240V line-to-line that is slightly kinder to PSU efficiency. Spreading miners evenly across all three phases keeps the service balanced and avoids overloading a single leg.
For the voltage consequences of each configuration see 208V vs 240V, and for the connectors that land these feeds see the IEC 60320 C19 / C20 connector.
In Simple Terms
Wye and delta are the two fundamental ways three-phase transformer windings are connected, and which one a facility uses determines what voltages are available to…