Manual

Chapter 1 Introduction
10 EM920 Power Quality and Revenue Meter
harmonic and interharmonic voltage, mains signaling
voltage
• High-voltage fast transient recorder; impulsive and low
frequency oscillatory transient overvoltages with peaks
up to 2kV and durations from 20 microseconds
• Ready-for-use compliance statistics reports with the
supplementary software
Fault Recorder
• Digital Fault recorder: three voltage and three/four
current channels, up to 10 external digital triggers for
monitoring circuit breakers and protection relays;
onboard overcurrent and undervoltage fault detector;
zero-sequence voltage and current, voltage and
current unbalance; programmable fault thresholds and
hysteresis
• Up to 50 Amp fault currents
• Ready-for-use fault reports with the supplementary
software - fault current magnitudes and duration,
coincident volt magnitude, fault waveforms and fast
RMS trace
Event Recorder
• Event recorder for logging internal diagnostics events,
setpoint and I/O operations
Waveform Recorders
• Three fast Waveform recorders: up to 7 channels
simultaneous recording of three voltage and three/four
current channels
• Fixed and event-controlled recording time
• Selectable sampling rate of 32, 64, 128 or 256
samples per cycle; 1-20 pre-fault cycles; 0-2048 post-
fault cycles in event-controlled mode; up to 3 min of
continuous recording at a rate of 32 samples per cycle
• Optional 4-channel transient voltage recording at 1024
samples per cycle (with the transient add-on module)
• Synchronized waveforms from multiple devices in a
single plot
• Exporting waveforms in COMTRADE and PQDIF file
formats
Data Recorders
• Sixteen Data recorders
• Programmable data logs on a periodic basis and on
any internal and external trigger; triggering from the
Fault recorder, PQ recorder or control setpoints;
exporting data trends in PQDIF file format
• Fast fault and PQ data profiling (trending) triggered
from the Fault and PQ recorders: 1/2-cycle to 10-min