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Input
Description
Necessary when
EF detection Mod GFC
is set
to "Io AND IoRef"
U3P
Three-phase voltages
URES
3
Residual voltage (measured)
Necessary when
EF detection Mod GFC
is set
to "Io OR Uo" or "Io AND Uo". Necessary also
if only main voltages are available but
Phase
voltage Meas
is set to "Accurate".
See the preprocessing function blocks in this document for the possible
signal sources. The
GRPOFF
signal is available in the function block called
Protection.
There are a few special conditions which must be noted with the configuration.
Table 905: Special conditions
Condition
Description
U3P connected to real measurements
The function can work with any two phase
voltage channels connected but it is recom-
mended to connect all three voltage chan-
nels.
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings.
For troubleshooting, check the contents of this chapter and also the preprocessing
blocks in this document. The configuration can be written to the protection relay
once the mismatch is corrected.
4.7.1.5
Operation principle
The function can be enabled and disabled with the
Operation setting. The
corresponding parameter values are "on" and "off".
The function consists of sub-functions which are described in the next sections.
3
Can be connected to
GRPOFF
if
EF detection Mod GFC is set to "Io" or "Io AND IoRef" or Phase
voltage Meas is set to "Ph-to-ph without Uo"
Protection functions
1MRS759142 F
944
REX640
Technical Manual