Phase Reversal Protection - ABB REM 610 Technical Reference Manual

1MRS 755537
4.1.4.8.
Motor protection Relay
Technical Reference Manual
where
t = operate time
I = NPS current
2
46 PICKUP = set pickup value
46 TDIAL = set time constant equals the motor constant, I
motor manufacturer)
Note!
When element 46 picks up during motor start up, no pickup signal will be generated.
Note!
Element 46 will be blocked during the tripping of the phase reversal element.
The figure below illustrates the inverse-time curves of element 46.
K=5 K=20 K=40 K=100
I 2 /FLA
1
0.1
1
Fig. 4.1.4.7.-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.
10 100
REM 610
2
x t (provided by the
2
46 PICKUP = 0.5 x FLA
46 PICKUP = 0.2 x FLA
46 PICKUP = 0.1 x FLA
1000 10000 100000
t/s
33