Function Block; Functionality; Analog Input Configuration; Operation Principle - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.4.4.2
4.4.4.3
4.4.4.4
4.4.4.5
754

Function block

GUID-3B4A16D2-1F48-41E0-8F2C-E32247917609 V1 EN
Figure 415: Function block

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 of the motor.
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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.

Analog input configuration

PREVPTOC has one analog group input which must be properly configured.
Table 688: Analog inputs
Input
I3P
See the preprocessing function blocks in this document for the
possible signal sources.
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".
exceeds the set limit. PREVPTOC operates
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values during the motor startup. The excessive I
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Description
Three-phase currents
1MRS759142 C
, and
2
2
REX640
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