ABB RELION REX640 Technical Manual page 1225

1MRS759142 F
non-directional distance zone or overcurrent stage, is required for fault indication.
The START and START_DLYD inputs are available for the purpose.
• The START input has no delay. Thus, a switch-onto-fault situation is immediately
signalled to SOTF control.
• START_DLYD is used when an additional delay is required to start the signal. The
switch-onto-fault situation is signalled to the SOTF control after the set
delay time .
Dead-line detector
The
function.
Table 1167: Options for dead line detection
Automatic SOTF Ini
DLD disabled
Voltage
Current
Current & Voltage
SOTF detection
The purpose of this module is to detect the switch onto fault situation based on
the current and voltage measurements. If the voltage, in any of the phases, is below
the
REX640
Technical Manual
The dead line detection should be used only when the voltage
transformers are located on the line side of the circuit breaker.
Automatic SOTF Ini setting is used to configure the internal dead line detection
Voltage dead Lin Val setting and simultaneously the current in the same phase
Description
The dead line detection function is disabled. This operation
mode must be applied when voltage transformers are loca-
ted on the bus side of the circuit breaker.
The dead line detection function is enabled and based sole-
ly on the undervoltage condition. A dead line condition is
declared, if all the phase voltages are below the
Lin Val setting. The dead line is detected if the dead line
condition is declared and simultaneously no fault is detected
by the and
START START_DLYD
dition is signalled to the SOTF control after the delay defined
Dead line time setting.
with the
The dead line detection function is enabled and based sole-
ly on the undercurrent condition. A dead line condition is
declared, if all the phase currents are below the
Lin Val setting. The dead line is detected if the dead line
condition is declared and simultaneously no fault is detected
by the and
START START_DLYD
tion is signalled to the SOTF control after delay defined with
Dead line time setting.
the
The dead line detection function is enabled and based on un-
dercurrent and undervoltage condition. A dead line condition
is declared, if all the phase currents are below the
dead Lin Val setting and simultaneously all phase voltages
Voltage dead Lin Val setting. The dead line is
are below the
detected if the dead line condition is declared and simulta-
neously no fault is detected by the
inputs. The dead line condition is signalled to the SOTF con-
trol after delay defined with the
Protection related functions
Operate
Voltage dead
inputs . The dead line con-
Current dead
inputs. The dead line condi-
Current
and
START START_DLYD
Dead line time setting.
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