SATEC EM920 Operation Manual - Manual (Page 23)

Chapter 2 Operating the EM920
Power Transformer/Line Loss Compensation
EM920 Power Quality and Revenue Meter 23
The EM920 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.
See Instrument Transformer Correction Setup on how to
program the ratio correction factors and phase angle errors
for external CTs and PTs and enable correction in the meter.
See
Device Options and Mode Control on how to enable and
disable correction in the meter via the front display.
NOTES
1. When transformer correction is enabled, it is applied to all
instrumentation, billing and power quality calculations
and waveforms.
2. Transformer correction does not affect test LED pulse
outputs.
3. Transformer correction is not operational in test mode
regardless of the option’s status.
Power Transformer/Line Loss Compensation
Loss compensation allows accounting for losses in power
transformers and/or power line in the event the billing and
metering points are located at different sides of the power
transformer or at different sides of the power line.
The calculated compensation values for kW and kvar losses
are added to the measured power quantities and energies.
The compensation values will be either positive, or negative
depending on whether losses are calculated at the supply side
or at the load side of the power transformer. They will be
positive if the meter is located at the load side while the
billing point is on the supply side, and negative in the
opposite direction.
The instantaneous kW and kvar losses for iron and copper
can be read and inspected via communications.
See Transformer/Line Loss Compensation Setup in Chapter 5
on how to program the loss constants and enable
compensation in your meter. See
Device Options and Mode
Control on how to enable and disable compensation in the
meter via the front display.
NOTES
1. When loss compensation is enabled, it is applied to all
billing data - one-second power values, power demands
and energy quantities. Loss compensation does not affect
instrumentation data – real-time power and fundamental
power values.
2. Loss compensation does not affect test LED pulse
outputs.
3. Loss compensation is not operational in meter test mode
regardless of the option’s status.