Instrumentation Metering - Satec Expertmeter EM720 Operation Manual

Chapter 2 Operating the EM720

Instrumentation Metering

RMS volts
RMS currents
Powers
Zero-sequence
Unbalance
Frequency
Total harmonics
Total interharmonics
Individual harmonics
Individual interharmonics
K-factor
Flicker
Symmetrical components
Phasors
20
the present billing period and for three previous billing
periods.
The display is automatically configured for your set of
billing registers and your tariff schedule. See
Data Displays
Instrumentation
measurements and time-integration for local and remote
power monitoring and control, and a source for power
quality evaluation and triggering the logical controller and
Fault recorder.
See Parameters for Monitoring and Logging
for a full list of the electricity and status measurements
provided by the EM720.
All RMS quantities are based on 1/2-cycle true RMS
measurements as per IEC 61000-4-30.
Voltage and current harmonic measurements are based on
10-cycle/50Hz
IEC 61000-4-7), sampled at a rate of 128 samples/cycle.
The EM720 uses dynamic sampling techniques to maintain
a steady sampling rate and avoid instrumentation errors
when the line frequency changes.
The meter
measurements as per IEC 61000-4-15.
The following table shows time-aggregation intervals
available for different RMS and power quantities.
Parameter 1/2
cycle
1 Taken from the energy measurement channel
2 Only for power quality evaluation
in Chapter 3 for the display layout.
metering
or 12-cycle/60Hz
provides short
1 200 ms
cycle
× × ×
× × ×
×
× × ×
× × ×
× ×
× ×
×
×
×
× ×
×
×
EM720 Power Quality and Revenue Meter
Instrumentation Metering
Billing Period
provides
in Appendix A
waveforms
and long term
1 3 sec 10
sec sec min
× ×
1 ×
×
1
×
× ×
× ×
× ×
× ×
×
× ×
real-time
(per
flicker
10 2
hours
× ×
× ×
× ×
×
×
×
×
2
×
2
×
×
× ×
×