Analog Channel Configuration - ABB RELION REX640 Technical Manual

1MRS759142 C
4.12.2.4
4.12.2.5
REX640
Technical Manual
CUBPTOC is suitable for the protection of internally fused, externally fused and
fuseless applications.
CUBPTOC has two stages of operation, that is, operation stage and alarm stage. In the
operating stage, CUBPTOC starts when the measured unbalance current exceeds the
set limit. The operation time characteristics can be selected to be either definite time
(DT) or inverse definite minimum time (IDMT). The operation under alarm stage is
either based on the DT characteristics or the faulty element counter of a capacitor
bank.
CUBPTOC has a blocking functionality. It is possible to block the function outputs,
timers or the function itself, if required.

Analog channel configuration

CUBPTOC has two analog group inputs which must be properly configured.
Table 961: Analog inputs
Input
IUNB
I3P
See the preprocessing function blocks in this document for the
possible signal sources.
There are a few special conditions which must be noted with the configuration.
Table 962: Special conditions
Condition
IUNB measurement
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings. For
troubleshooting, check the contents of this chapter and also the preprocessing blocks
in this document. The configuration can be written to the protection relay once the
mismatch is corrected.
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off". The current unbalance
protection for shunt capacitor banks operates on the DFT measurement mode.
Protection functions
Description
Unbalance current (measured)
Three-phase currents
Description
The function requires that the unbalance current
measurement is connected to the RESTCTR
function block.
Section 4
1021