Figure 441: Functional module diagram
Trigger
This module is used for detecting a possible fault immediately after circuit breaker
closing. The use of external protection function, typically the start signal from a
non-directional distance zone or overcurrent stage, is required for fault indication.
The
START
and
START_DLYD
inputs are available for the purpose.
•
START
input has no delay. Thus, a switch-onto-fault situation is immediately
signalled to SOTF control.
•
START_DLYD
input 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
Operate delay time.
Dead-line detector
The dead line detection should be used only when the voltage
transformers are located on the line side of the circuit breaker.
The
Automatic SOTF Ini setting is used to configure the internal dead line detection
function.
Protection related functions
1MRS757644 H
830
620 series
Technical Manual
