ABB RELION REX640 - 4.12.2.7 Signals; CUBPTOC Input signals; CUBPTOC Output signals; 4.12.2.8 CUBPTOC Settings

Connect the phase current analog input I_A and unbalance current
I_UNB to the protection relay for the CUBPTOC function to start working.
Steps to measure natural unbalance current
1. The setting Natural Comp Enable must be set to “TRUE”.
2. The capacitor bank must be energized.
3. The capacitor bank compensated unbalance current I_COM_AMPL is observed
from Monitored data.
4. The command Record unbalance must be activated by selecting the
value “Record” which stores the unbalance reference for future unbalance
calculations.
5. The compensated unbalance current ( I_COM_AMPL) is re-checked to be
approximately zero.
The natural unbalance recording should be made only during the steady-
state condition and when all the capacitor bank elements are assumed to
be in service.
4.12.2.7 Signals
CUBPTOC Input signals
Table 1068: CUBPTOC Input signals
Name Type Default Description
IUNB SIGNAL - Analog input
I3P SIGNAL - Three-phase currents
BLOCK BOOLEAN 0=False Block signal for acti-
vating the blocking
mode
CUBPTOC Output signals
Table 1069: CUBPTOC Output signals
Name Type Description
OPERATE BOOLEAN Operate
START BOOLEAN Start
ALARM BOOLEAN Alarm
4.12.2.8 CUBPTOC Settings
Table 1070: CUBPTOC Group settings (Basic)
Parameter
Values (Range) Unit Step Default Description
Alarm mode
1=Normal
1=Normal Mode of operation
for Alarm stage
Table continues on the next page
Protection functions 1MRS759142 F
1128 REX640
Technical Manual