En 61869-2 <FRESH • 2026>

One of the most significant aspects of EN 61869-2 is the designation of accuracy classes, which dictate the permissible error for measuring and protection cores.

| Type | Application | Accuracy classes (examples) | Notes | |------|-------------|----------------------------|-------| | | Billing, panel meters | 0.1, 0.2, 0.5, 1, 3 | Low phase error, high accuracy at normal load. | | Protection CTs | Relay inputs, fault detection | 5P, 10P (also PX/TPX/TPY/TPZ for special cases) | High accuracy under fault currents. | | Dual-purpose CTs | Both measurement & protection | e.g., 0.5/5P | Two cores or composite class rating. | en 61869-2