25
Time synchronization is always triggered on the rising edge of the digital input
signal. The time is adjusted in steps of five milliseconds per synchronization pulse.
The typical accuracy achievable with time synchronization via a digital input is ±2.5
milliseconds for second-pulse and ±5 milliseconds for minute-pulse
synchronization.
The pulse length of the digital input signal does not affect time
synchronization.
If time synchronization messages are received from a communication
protocol as well, they have to be synchronized within ±0.5 minutes at
minute-pulse or ±0.5 seconds at second-pulse synchronization.
Otherwise, the relay’s real-time clock makes sudden minute or second
jumps in either direction. If it is possible that synchronization messages
from the communication protocol are delayed more than 0.5 seconds,
minute-pulse synchronization must be used.
5.1.2. Measurements
The table below presents the measured values which can be accessed through the
HMI.
Table 5.1.2.-1 Measured values
Target Description
l
a
Current measured on phase l
a
l
b
Current measured on phase l
b
l
c
Current measured on phase l
c
I
n
Measured ground-fault current
I
2
Calculated NPS current
TH LEVEL Thermal level
Start time Start-up time of the latest motor start up
66 value Cumulative start-up time counter
Rest. Dis Time to next possible motor start up
Running time Motor running time
Max IP Maximum phase current during motor start up
Max IP Maximum phase current after motor start up
Max I
n
Maximum ground-fault current after motor start up
Min IP Minimum phase current after motor start up
Min I
n
Minimum ground-fault current after motor start up
1 min. The average current of the three phase-to-phase
currents during one minute
n min. The average current of the three phase-to-phase
currents during the specified time range
Max I The maximum of one-minute average current of the n
min
Motor Protection Relay
Technical Reference Manual - ANSI Version
REM 610REM 610
1MRS755537
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