Ratio and phase angle error correction can be applied to external CTs and PTs to achieve overall metering installation accuracy, 

or be used in any metering installation to optimize the accuracy of the metering data. 

The user can program up to both ratio correction and phase angle error curves covering the typical transformer operating range. 

SATEC power meter is able to calculate the transformer errors dynamically based on the transformer performance characteristics and 

the actual CT current and PT voltage signals appearing at the meter, to interpolate to the actual measured operating point and to apply the interpolated error corrections to the meter calculations. 

Instrument Transformer Correction Setup 

Transformer correction allows to compensate ratio and phase angle inaccuracies of the voltage and current instrument transformers. 

Select General Setup from the Meter Setup menu, and then click on the Transformer Correction tab. See example for PM180.

The available options are listed in the following table. 





None, V1-V4, I1-I4, I1x/DFR-I4x/DFR

Voltage/ measurement current and current fault recorder channels

Ratio Correction Factor


The ratio of the true transformer ratio to the marked ratio

Phase Angle Error

+/-600 minutes

The phase displacement, in minutes, between the primary and secondary values. The phase angle of a transformer is positive when the secondary value leads the primary value. 

* V4, I4 and DFR is supported in PM180.

Define linearity error and phase angle shift error based on the transformer’s accuracy characteristics. 

The compensation is applied over the full operating range of the transformer.



1. When transformer correction is enabled, it is applied to all instrumentation, billing and power quality calculations and waveforms (PM174,PM175,PM172N-EH transformer correction doesn't affect waveforms). 

2. Transformer correction does not affect test LED pulse outputs. 

3. Transformer correction is not operational in test mode.