How should 220 V versus 380 V be specified for commercial heating elements?
For commercial heating elements, choose 220 V single-phase only where the machine has small total power and single-phase supply; specify 380 V three-phase for high power or grouped multi-tube loads, then verify per-phase current and breaker capacity. Confirm sheath diameter, material, surface load, protection rating, mounting geometry and thermostat matching so nameplate, wiring diagram and site supply agree. Mismatch raises sheath temperature, ages insulation or underheats. Lock voltage, wattage, tolerance and connection in the technical agreement as the sole basis for delivery and retest.