ABB RELION REX640 - Page 661

PROT_ACTIVE
BLOCK
Protecon
communicaon
supervision
(PCSITPC)
AND
Operaon ”Test/blocked”
Operaon ”Off”
OK
Figure 372: Operation logic of the fail safe function
The function can also be set into “test/blocked” state with the Operation setting.
This can also be utilized during the commissioning.
The BLOCK input is provided for blocking the function with the logic. When the
function is blocked, the monitored data and measured values are still available but
the binary outputs are blocked. When the function is blocked, the direct inter-trip is
also blocked.
The PRO_ACTIVE output is always active when the protection function is capable
of operating. PRO_ACTIVE can be used as a blocking signal for backup protection
functions.
Timer
Once activated, the timer activates the STR_LS_LOC output. Depending on the value
of the set
Operating curve type , the timer characteristics are according to DT or
IDMT. When the operation timer has reached the value set with the Operate delay
time in the DT mode or the maximum value defined by the inverse time curve, the
OPR_LS_LOC output is activated. When the operation mode is according to IDMT,
Low operate value is used as reference value (Start value) in the IDMT equations
presented in the Standard inverse-time characteristics section.
A timer reset state is activated when a drop-off situation happens. The reset is done
according to the DT characteristics.
For a detailed description of the timer characteristics, see the
Chapter 11
General function block features section in this manual.
Instantaneous high stage
In addition to the stabilized low stage, LNPLDF has an instantaneous high stage.
The stabilizing is not done with the instantaneous high stage. The instantaneous
high stage operates immediately when the differential current amplitude is higher
than the set value of the
High operate value setting. If the ENA_MULT_HS input is
active, the High operate value setting is internally multiplied by the High Op value
Mult setting.
1MRS759142 F
Protection functions
REX640
Technical Manual
661