Measurements - ABB REU 610 Technical Reference Manual

1MRS755972
5.1.2.
Voltage Relay
Technical Reference Manual - ANSI Version
If the synchronization pulse differs more than ±0.05 seconds for second-pulse
or ±2 seconds for minute-pulse synchronization from the relay's real-time
clock, the synchronization pulse is rejected.
Time synchronization is always triggered on the rising edge of the digital
input signal. The time is adjusted by accelerating or decelerating the relay's
clock. By this way the clock neither stops nor makes sudden jumps during the
time adjustment. 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 time difference may
appear as rounding errors. If it is possible that the
synchronization messages from the communication protocol are
delayed more than 0.5 seconds, minute-pulse synchronization
must be used.
When the minute-pulse synchronization is active and long time
format is sent via a communication protocol, the protocol's
second and millisecond part is ignored. The protocol's minute
part is rounded to the nearest minute. Short time format is
ignored altogether.
When the second-pulse synchronization is active and long or
short time format is sent via a communication protocol, the
protocol's millisecond part is ignored. The protocol's second-part
is rounded to the nearest second.

Measurements

The table below presents the measured values which can be accessed through
the HMI.
Table 5.1.2.-1 Measured values
Indicator Description
U Measured phase-to-phase voltage U
ab
U Measured phase-to-phase voltage U
bc
U Measured phase-to-phase voltage U
ca
U Measured residual voltage U
n
ab
bc
ca
n
REU 610
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