Phase Reversal Protection; Cumulative Start-Up Time Counter - ABB REM 610 Technical Reference Manual

1MRS755537
5.1.4.8.
5.1.4.9.
Motor Protection Relay
Technical Reference Manual - ANSI Version
Fig. 5.1.4.7.-1 Inverse-time curves of element 46

Phase reversal protection

The phase reversal protection is based on the calculated negative-phase-sequence
current and detects too high NPS current values during motor start up, caused by
incorrectly connected phases, which in turn will cause the motor to rotate in the
opposite direction.
When the calculated NPS current value exceeds 75 per cent of the maximum phase
current value, the phase reversal element (46R) will generate a trip signal after a
fixed 200 ms' operate time.
The element will be reset in 200 ms after the calculated NPS current value has fallen
below 75 per cent of the maximum phase current value.
The phase reversal element can be set out of operation in SGF3.
The unbalance element will be blocked during the tripping of the phase
reversal element.

Cumulative start-up time counter

The cumulative start-up time counter detects too frequent start-up attempts, which
cause overheating of the motor.
The start-up time of every motor start up is added to a register, 66 value. When the
register's value exceeds the set restart disable value, 66, any attempt to restart the
motor will be disabled.
REM 610 REM 610
A060577
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