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Residual current magnitude correction of an external CT can be made using the
Amplitude Corr setting.
Residual current angle correction of an external CT can be made using the
Angle
correction setting.
Rated secondary Val (RSV) setting in combination with Primary current setting
defines the ratio for sensor use. See
Chapter 3.12 Sensor inputs for currents and
in this manual for further details.
Rated secondary Val should be set to same value in all RESTCTR instances
which are configured to sensor measurement.
The
Reverse polarity setting is used to reverse the polarity of the residual CT.
The
WARNING
output in the receiver is activated if the synchronization accuracy of
the sender or the receiver is worse than 4 μs. The output is held on for 10 seconds
after the synchronization accuracy returns within limits.
The
ALARM
in the receiver is activated if the synchronization accuracy of the sender
or the receiver is not within tolerances. The output is held on for 10 seconds after
the synchronization accuracy returns within limits. If the effect on protection is
negligible, the
WARNING
or
ALARM
outputs are not activated.
The
SMV Max Delay setting defines how long the receiver waits for the SMV
frames before activating the
ALARM
output. This setting can be accessed via
Configuration > System. Waiting for the SMV frames also delays the local
measurements of the receiver to keep them correctly time aligned. The
SMV Max
Delay values include sampling, processing and network delay.
Frequency adaptive measurements for residual current can be activated with the
setting
Frequency adaptivity. Two selections are provided.
Table 122: Frequency adaptivity setting for residual current measurement
Setting value
Description
Disable
Frequency adaptive measurements are disabled for this
RESTCTR. Measurements are fixed to nominal frequency de-
fined with Configuration > System > Rated frequency.
Enable
Frequency adaptive measurements are enabled. In this case,
the estimated network frequency is defined by another pre-
processing block.
RESTCTR setting
Frequency adaptivity is visible only if system setting
Configuration > System > Frequency adaptivity is set to "Enable".
3.17.2.4
Signals
RESTCTR Input signals
Table 123: RESTCTR Input signals
Name
Type
Default
Description
IRES
SIGNAL
-
Residual current
1MRS759142 F
Basic functions
REX640
Technical Manual
195