Second Harmonic Stage / Inrush (68) - VAMP 140 Operation And Configuration Instructions

VAMP Ltd
2.2.4.
VM140.EN011
Overcurrent and earth-fault relay
Technical description
Parameters of the unbalance protection stage:
I > (46)
2
Parameter:
Measured I2/I1
value
Setting I2>
values
t>
SCntr
Recorded
values
TCntr
Flt
Edly

Second harmonic stage / inrush (68)

This stage is mainly used to block other stages. The ratio
between the second harmonic component and the fundamental
frequency component is measured on all the phase currents.
When the ratio in any phase exceeds the setting value, the
stage gives a start signal. After a settable delay, the stage gives
a trip signal.
The start and trip signals can be used for blocking the other
stages. The trip delay is irrelevant if only the start signal is
used for blocking.
The trip delay of the stages to be blocked must be more than 60
ms to ensure a proper blocking.
Im1
>
Im2
MAX
Im3
Block
Setting
2.Harm
Figure 2.2.4-1. Block diagram of the second harmonic stage.
Vamp 24h support phone +358 (0)40 573 6316
Value/unit:
% Negative phase sequence
current I2/I1
% Setting value
s Operation time
Start counter (Start) reading
Trip counter (Trip) reading
% Max. fault current
% Elapsed time as compared to
the set operate time, 100% =
tripping
&
t t
s r
Delay
VAMP 140
2ndHarm
Start
& Register
event
Trip
t
&
Register
event
Enable events
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