Operation Principle - ABB RELION REX640 Technical Manual

Section 3
Basic functions
3.20.16.5
Table 237: Switching operation
Control input signals
SWITCH_TO SWITCH_TO
2 3
FALSE FALSE
TRUE FALSE
TRUE
1)
x
1) 1)
x x
1) No difference
254
There are a few special conditions which must be noted with the configuration.
Table 236: Special conditions
Condition
U3P1/U3P2/U3P3/U3P4 connected to real
measurements
URES1/URES2/URES3/URES4 calculated

Operation principle

The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "on" and "off".
For this function, the setting is hidden and fixed to "on".
The switch logic depends on inputs SWITCH_TO2, SWITCH_TO3 and
SWITCH_TO4. Source 1 is selected as default and switching is done on increased
priority.
GRPOFF signal must be connected to unused voltage inputs. GRPOFF
signal is available as output from the Protection function block.
Outputs
SWITCH_TO SOURCE1
4
FALSE TRUE
FALSE FALSE
FALSE FALSE
TRUE FALSE
If the numbers of channels connected to U3P1...U3P4 and
URES1...URES4 does not match with the number of connected
SWITCH_TOx inputs, the configuration of the function fails.
Outputs ALARM and URES_ALARM indicate bad quality data of system measurements
for selected U3P and URES, respectively.
Description
The function requires that at least one voltage
channel is connected.
The function requires that all three voltage
channels are connected to calculate the residual
voltage. Setting
that particular UTVTR.
SOURCE2 SOURCE3
FALSE FALSE
TRUE FALSE
FALSE TRUE
FALSE FALSE
VT connection must be "Wye" in
SOURCE4 Source for
U3P
FALSE U3P1
FALSE U3P2
FALSE U3P3
TRUE U3P4
Technical Manual
1MRS759142 C
Source for
URES
URES1
URES2
URES3
URES4
REX640