Scaling For Pt And Ct Ratios - GE PACSystems RX3i User Manual

2

Scaling for PT and CT Ratios

The IC694PSM001 module reports the voltages and currents measured at the
IC694ACC200 terminals. Therefore, the application logic must correct for PT and CT
ratios to reflect the actual power grid voltages, currents, powers and energies.
Example:
Using 480V:120V PTs requires the application logic to multiply the reported voltage values
by 4. Using 100:5 CTs requires the application logic to multiply the reported current values
by 20. Since power and energy combine voltage and current, the reported power and
energy values must both be multiplied by 80 (4 x 20).
GFK-2749 Chapter 2 Installation 2-19