VAMP Ltd
Feeder and motor manager
Technical description
VAMP 257
VM257.EN002
VAMP 24h support phone : +358 (0)20 753 3264
35
0
.
1
0
.
2
0
.
4
0
.
4
0
.
5
0
.6
0
.
7
0
.8
0
.9
1
.
0
I /I
2 MOT
10
1
100
1000
Operation
time
(s)
K =40
1
K =0.2
2
K =0.05
2
K =0.2
2
K =0.2
2
K =0.05
2
K =0.05
2
K =1
1
Figure 2.3.6-1. Inverse operation delay of current unbalance stage I
2
>. The
longest delay is limited to 1000 seconds (=16min 40s).
2.3.7.
Phase reversal / incorrect phase sequence
protection (47)
NOTE!
This function is available only in motor protection mode.
The phase sequence stage prevents the motor from running in
the wrong direction, thus protecting the load.
When the ratio between negative and positive sequence current
exceeds 80%, the phase sequence stage starts and trips after
100 ms.
Parameters of the incorrect phase sequence stage:
I2>> (46)
Parameter Value/unit Description
Measured
value
I2/I1 %
Neg. phase seq. current/pos.
phase seq. current
SCntr
Start counter (Start) reading
TCntr
Trip counter (Trip) reading
Flt
%
Max. value of fault current
Recorded
values
EDly %
Elapsed time as compared to
the set operate time, 100% =
tripping