Alternative solution for metering and protection devices compatible with lo-po instrument transformers. typically recommended in installation conditions where the output cable is long or multisignal, or when the rated burden is too high. the active version is needed when the relay / meter cannot integrate the signal from the passive current sensor (rogowski coil).
very low voltage signals proportional to the primary voltage and / or current. features: high linearity, accuracy class up to 0,5 in the operating temperature range, analogue calibration in factory, compatible with output cables up to 100 m, no significant influence of the secondary burden. limits: auxiliary power supply needed, wide dinamic range but limited by the electronic circuit, rated frequency only.
Rated primary current, 1pr
300 A (or 630 A)
50 / 60 Hz
Highest voltage for equipment, Um
Rated power-frequency withstand voltage
Rated primary time constant for transient performance, tpr