9.5
Date Code 20080918 Instruction Manual SEL-749M Relay
Analyzing Events
Event Reporting
Currents, Voltages, and RTD Temperatures
The Current Mag. (A) fields display the primary current magnitudes at the
instant the TRIP relay word bit asserted or the ER equation asserted. The
currents displayed are listed below:
➤ Line Currents (IA, IB, IC)
➤ Neutral Current (IN)
➤ Residual Current (IG), calculated from IA, IB, IC
The Voltage Mag. (V) fields, optional voltage card required display the
primary voltage magnitudes at the instant the TRIP relay word bit asserts or
the ER equation asserts. The voltages displayed are listed below:
➤ DELTA_Y := WYE
➢ Phase-to-Neutral Voltages (VAN, VBN, VCN)
➢ Residual Voltage VG, calculated from VA, VB, VC
➤ DELTA_Y := DELTA
➢ Phase-to-Phase Voltages (VAB, VBC, VCA)
The Hottest RTD (°C) fields display the hottest RTD reading in each RTD
group. The hottest RTD temperatures in degrees centigrade (°C) are listed
below:
➤ Winding
➤ Bearing
➤ Ambient
➤ Other
Event History
The event history report gives you a quick look at recent relay activity. The
relay labels each new event in reverse chronological order with
1 as the most
recent event. See Figure 9.2 for a sample event history. Use this report to view
the events that are presently stored in the SEL-749M.
The event history contains the following:
➤ Standard report header
➢ Relay and terminal identification
➢ Date and time of report
➢ Time source (if IRIG-B model)
➤ Event number, date, time, event type (see Table 9.1)
➤ Maximum motor current
➤ Target LED status
PTC Fail Trip PTCFLT AND TRIP
CommIdleLossTrip (COMMIDLE OR COMMLOSS) AND TRIP
Trigger Serial Port TRI command
Stop Command Serial Port or Front-Panel Stop Command
ERTrigger ER Equation assertion
Trip TRIP (trip from any cause not defined above)
Table 9.1 Event Types (Sheet 2 of 2)
Event Type Event Type Logic
Courtesy of NationalSwitchgear.com
To Next Page
