ABB RELION REX640 Technical Manual page 838

Protection functions
4.4.4.1 Identification
Function description
Phase reversal protection
4.4.4.2 Function block
Figure 474: Function block
4.4.4.3 Functionality
The phase reversal protection function PREVPTOC is used to detect the reversed
connection of the phases to a three-phase motor by monitoring the negative phase
sequence current I
PREVPTOC starts and operates when I
on definite time ( DT) characteristics. PREVPTOC is based on the calculated I
the function detects too high I
values are caused by incorrectly connected phases, which in turn makes the motor
rotate in the opposite direction.
The function contains a blocking functionality. It is possible to block function
outputs, timer or the function itself.
4.4.4.4 Analog input configuration
PREVPTOC has one analog group input which must be properly configured.
Table 762: Analog inputs
Input
I3P
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.
4.4.4.5 Operation principle
The function can be enabled and disabled with the
corresponding parameter values are "On" and "Off".
838
of the motor.
2
2
See the preprocessing function blocks in this document for the possible
signal sources.
IEC 61850 IEC 60617
identification identification
PREVPTOC I2>>
exceeds the set limit. PREVPTOC operates
2
values during the motor start-up. The excessive I
Description
Three-phase currents
Operation setting. The
1MRS759142 F
ANSI/IEEE C37.2
device number
46R
, and
2
2
REX640
Technical Manual