Issue
What does "CT/PT Correction Points" mean in the Instr Xformer Correction (ITC) Module on an ION meter?

Product Line
ION meters

Environment
ION meters using the Instrument Transformer Correction (ITC) Module for CT/PT accuracy adjustments.

Resolution
In ION meters, the Instr Xformer Correction (ITC) Module is used to correct inaccuracies in current transformers (CTs) and potential transformers (PTs). This module applies correction factors for ratio errors and phase angle errors to instrument transformers, reducing or eliminating the need to replace transformers in installations where high accuracy is required.

The module requires entering a set of example data, then applies interpolation based on the data set to correct inaccurate voltage and current values. In the module, the Phase Correction Data setup register is used to enter a string of delimited pairs of test points and associated error for the phase angle of the CT or PT.

• The test point is expressed as a percentage of the rated secondary nominal rating.
• The phase angle error is expressed as a real value in minutes.

The term CT/PT Correction Points refers to these test points used in the ITC module to define the correction curve for CTs and PTs.