Undervoltage

Protects against dangerous voltage drops (e.g. < 190V). It is essential for devices with motors and compressors (air conditioners, refrigerators, pumps), which overheat and are damaged when they try to operate at low voltage.

Phase Asymmetry

Checks whether there is a large voltage deviation between the 3 phases (e.g. L1 = 230V, L2 = 180V). Protects three-phase devices from irregular operation, vibrations, and overheating.

Phase Sequence

Ensures that the phases are connected in the correct sequence (L1, L2, L3). Prevents three-phase motors and pumps from rotating in reverse, avoiding serious mechanical damage.