ABB RELION REX640 Technical Manual page 695

1MRS759142 C
REX640
Technical Manual
I_A
I3P
detector
Blocking
BLOCK
I_B
I3P
detector
Blocking
BLOCK
I_C
I3P
detector
Blocking
BLOCK
GUID-B1BA43AA-0ED9-4C90-B564-C0268770C4E1 V2 EN
Figure 380: Functional module diagram
The module diagram illustrates all the phases of the function. Functionality for phases
A, B and C is identical.
All three phases have independent settings.
Level detector
The module compares differential currents I_A calculated by the peak-to-peak
measurement mode to the set Operate value. The Timer module is activated if the
differential current exceeds the value of the Operate value setting.
Timer
Once activated, Timer activates the START output. The time characteristic is
according to DT. When the operation timer reaches the value set by Minimum operate
time, the OPERATE output is 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 operation timer resets and the START output is deactivated.
Timer Timer
Level
t t
logic
Timer Timer
Level
t t
logic
Timer Timer
Level
t t
logic
Section 4
Protection functions
START
OPERATE
START
OPERATE
START
OPERATE
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