Figure 137: Functional module diagram
Level detector 1
This module compares the phase currents (RMS value) to the
Start value
setting.
The
Operation mode
setting can be used to select the "Three Phase" or "Single
Phase" mode.
If in the "Three Phase" mode all the phase current values are less than the value of
the
Start value
setting, the condition is detected and an enable signal is sent to the
timer. This signal is disabled after one or several phase currents have exceeded the
set
Start value
value of the element.
If in the "Single Phase" mode any of the phase current values are less than the value
of the
Start value
setting, the condition is detected and an enable signal is sent to
the timer. This signal is disabled after all the phase currents have exceeded the set
Start value
value of the element.
The protection relay does not accept the
Start value
to be smaller than
Current block value
.
Level detector 2
This is a low-current detection module that monitors the de-energized condition of
the protected object. The module compares the phase currents (RMS value) to the
Start value low
setting. If all the phase current values are less than the
Start value
low
setting, a signal is sent to block the operation of the timer.
Timer
Once activated, the timer activates the START output and the phase-specific ST_X
output. The time characteristic is according to DT. When the operation timer has
reached the value set by
Operate delay time
, the OPERATE output and the phase-
specific OPR_X output are activated. If the fault disappears before the module
operates, the reset timer is activated. If the reset timer reaches the value set by
Reset delay time
, the operate timer resets and the START output is deactivated.
The timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation and the set operating time. The value is
available through the monitored data view.
The BLOCK signal blocks the operation of the function and resets the timer.
Protection functions
1MRS758755 C
274 REC615 & RER615
Technical Manual
To Next Page
Loading...
