1MRS 750942-MUM
Combined Overvoltage and Undervoltage Relay
Technical Reference Manual
REU 523
33
When an overvoltage stage trips, both the measured voltage at the time of the trip
and the maximum voltage captured during the start will be stored.
The above applies to the undervoltage stages, too. Stored values are the minimum
voltage value, the measured voltage at the time of the trip, the minimum
positive-phase-sequence value and start durations.
4.1.10.
External serial communication
4.1.10.1.
Communication ports
The REU 523 is provided with two serial communication ports: an optical
PC-connection on the front panel and an RS-485 connection on the rear panel.
The D9S-type RS-485 connector is used to connect the relay to the distribution
automation system. This connection enables the use of either the SPA bus
communication protocol or the IEC 60870-5-103 communication protocol. The
fibre-optic interface module RER 103 is used to connect the relay to the fibre-optic
communication bus.
Although the RER 103 supports LON bus communication, the REU 523 does not
support the LON protocol. LON communication requires a separate LSG device.
Table 4.1.9-1
Recorded data
REGISTER Recorded data
EVENT1
• The maximum voltage value measured during the start sequence of an
overvoltage stage as a multiple of the rated voltage, U
n
.
• The minimum voltage value measured during the start sequence of an
undervoltage stage as a multiple of the rated voltage, U
n
.
• The voltage measured at the time of the trip as a multiple of the rated
voltage, U
n
.
• The minimum value of the positive-phase-sequence voltage during the start
sequence of an undervoltage stage as a multiple of the rated voltage, U
n
.
• Duration of the last starts of stages t>, t>>, t< and t>>, expressed as a
percentage of the set operate time, or of the calculated operate time at IDMT
characteristic. The timing will start when a stage starts. A value other than
zero means that the corresponding stage has started whereas a value which
is 100% of the set or calculated operate time indicates that the stage has
tripped. If the operate time for a stage has elapsed but the stage is blocked,
the value will be 99% of the set or calculated operate time.
• Time stamp for the event. The time when the last stage drops off will be
stored. The time stamp is displayed in two registers, one including the date
expressed as yy-mm-dd, and the other including the time expressed as
HH.MM; SS.sss.
EVENT 2
Same as EVENT 1.
EVENT 3
Same as EVENT 1.
EVENT 4
Same as EVENT 1.
EVENT 5
Same as EVENT 1.
Number of
starts
• The number of times each protection stage, i.e. U>, U>>, U< and U<<, has
started, counting up to 999.
