SATEC EM720 Operation Manual - Manual (Page 25)

Chapter 2 Operating the EM720
Operating the Fast Transient Recorder
EM720 Power Quality and Revenue Meter 25
currents while the event continues, using a variable recording
rate and variable averaging intervals.
See Configuring the EN50160 Recorders in Chapter 5 and
EN50160 Evaluation and Recording in Appendix E for more
information on configuring and operating the PQ recorder.
Operating the Fast Transient Recorder
The fast transient recorder is provided with EM720T meters.
It can detect impulsive and low frequency oscillatory
transient overvoltages with peaks up to 2kV and durations
from 20 microseconds.
The recorder does not require any special setup above a
conventional PQ recorder setup for transient overvoltages.
Waveform log #3 is especially dedicated for fast transient
waveforms. It automatically stores 1-cycle voltage
waveforms sampled at a rate of 1024 samples/cycle
whenever a transient overvoltage is detected.
Unlike a basic transient recorder provided with the EM720
that detects and records transient voltages between phase
conductors and a neutral terminal (in 4LN3 and 3LN3
configurations), or between two phase conductors (in line-to-
line configurations), the fast transient recorder detects
transient voltages between phase conductors and a ground
terminal and between the neutral and a ground terminal
regardless of a wiring configuration.
See the EM720 Installation Manual for the terminal location
and wiring diagrams. To help you check your voltage
connections, the EM720 provides 1-cycle phase RMS voltages
V1x through V3x, and 1-cycle neutral voltage V4x relative to
the ground terminal, that you can monitor via PAS.
Operating the Fault Recorder
The programmable Fault recorder stores time-tagged fault
events into the fault event report. It can be triggered
externally through a digital input or internally from the
embedded fault detector.
The fault detector can automatically detect different fault
categories using the meter sub-cycle measurements. Fault
triggers have programmable thresholds and hysteresis and
can be adjusted for specific substation conditions.
The Fault recorder is programmable for triggering the
Waveform recorder to record fault voltage and current
waveforms before, within and after a fault event, and can
trigger the Data recorder for fast profiling of RMS voltages
and currents during a fault.
See Configuring the Fault Recorder in Chapter 5 for more
information on operation of the Fault recorder.
Communicating with the EM720
Communication with the EM720 is provided either via the
embedded optical IR port, or via the replaceable
communication ports. See the EM720 Installation Manual for