Schweitzer Engineering Laboratories SEL-701, Instruction Manual

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701 Motor Protection Relay
Date Code 20010719
Metering & Monitoring
Motor Start Report
8.12
Motor Start Report
Each time the relay detects a motor start, it stores a motor start report. The five
latest motor start reports are stored in nonvolatile memory. View any of the five latest
motor start reports using the serial port
MSR n command, where n = 1–5. Each report
consists of two parts: a summary and the start data.
Summary Data
Each motor start report contains a summary. The summary shows the following
information:
Date and time of the start.
Number of motor starts since last reset.
Motor acceleration time.
Starting % Thermal Capacity.
Maximum Starting Current.
Minimum Starting Voltage, if voltages are present.
The motor acceleration time is calculated from the time the phase current
magnitude exceeds 2.5 times Full Load Amps until the current magnitude falls below
that level. The Starting % Thermal Capacity value is the thermal element capacity used
at the end of the start, expressed in percent of the trip value.
Start Data
The motor start data is taken every 5 cycles for 3600 cycles, starting 5 cycles after
the phase current magnitude exceeds 2.5 times Full Load Amps. The relay stores the
following data every 5 cycles:
Magnitude of A-, B-, and C-phase currents.
Magnitude of neutral current, I
N.
% Thermal Capacity.
Magnitude of AB, BC, and CA phase-to-phase voltages, if included.
The start data is output in a comma-delimited text format for easy integration into
computer spreadsheets for motor starting analysis.
Report Format
The motor start report comma delimited format makes the data easy to use with
spreadsheets or other visualization software. Use the MSR F serial port command to
view or capture the report format. The relay responds to the MSR F serial port
command by sending a motor start report whose data fields are filled with zeroes.