Phase Reversal Protection Prevptoc; Motor Negative-Sequence Overcurrent Protection Mnsptoc - ABB Relion 630 Series Applications Manual

Motor protection and control

Hide thumbs Also See for Relion 630 Series:

Table of Contents

Section 3

REM630 variants

3.2.6.6

3.2.6.7

Phase reversal protection PREVPTOC

The phase reversal protection is used for detecting the reversed connection of the

phases to a three-phase motor by monitoring the negative-phase sequence current

of the motor.

The operation of the function is based on the detection of very high negative-

sequence currents during motor start up due to incorrect phase connections to the

motor. The condition causes the motor to rotate in the reverse direction. The

function starts and operates when the negative-sequence current exceeds the

corresponding set limits. Phase reversal protection is blocked when current circuit

supervision detects a failure. Operate signal is used to trigger the disturbance recorder.

Two instances of negative-sequence overcurrent detection are provided for

protection against single-phasing, unbalance load or unsymmetrical voltage. The

set of three phase currents, I3P, is connected to the inputs.

The function operates in two modes, the definite time mode (DT) and the inverse

definite minimum time (IDMT) mode, for which two instances of the function

block are used. The negative-sequence overcurrent protection is blocked in case of

current circuit supervision failure is activated.

The common operate and start signal from the both MNSPTOC functions are

connected to an OR-gate to form a combined negative-sequence overcurrent

operate and start signal which is used to provide a LED indication on the LHMI.

Also separate start and operate signal from the both MNSPTOC functions is

connected to the disturbance recorder.

1MRS756785 A

REM630

Application Manual

Table of Contents

Rem630