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REF 610
4.1.2.
4.1.3.
16
Feeder Protection Relay
Technical Reference Manual
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...-2.5 milliseconds for second-pulse and +5...-5 milliseconds for minute-pulse
synchronization.
Note!
The pulse length of the digital input signal does not affect time synchronization.
Measurements
The table below presents the measured values which can be accessed through the
HMI:
Table 4.1.2-1
Measured values
Indicator
Description
L1
Current measured on phase I
L2
Current measured on phase I
L3
Current measured on phase I
I
Measured earth-fault current
0
∆I
Calculated phase unbalance
θ
Calculated thermal level
I
One-minute demand value
min
1_
I
Demand value during the specified time range
min
n_
Max I
Maximum one-minute demand value during
the specified time range
Configuration
Fig. 4.1.3.-1 illustrates how the internal and digital input signals can be configured
to obtain the required protection functionality.
L
1
L
2
L
3
1MRS 755310
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