Download VAMP 255/245/230

VAMP 255/245/230
Feeder and motor managers
Technical description
VAMP Ltd
Three independent stages
There are three separately adjustable overcurrent stages: I>,
I>> and I>>>. The first stage I> can be configured for definite
time (DT) or inverse time operation characteristic (IDMT). The
stages I>> and I>>> have definite time operation
characteristic. By using the definite delay type and setting the
delay to its minimum, an instantaneous (ANSI 50) operation is
obtained.
Figure 2.5-1 shows a functional block diagram of the I>
overcurrent stage with definite time and inverse time operation
time. Figure 2.5-2 shows a functional block diagram of the I>>
and I>>> overcurrent stages with definite time operation delay.
Inverse operation time
Inverse delay means that the operation time depends on the
amount the measured current exceeds the pick-up setting. The
bigger the fault current is the faster will be the operation.
Accomplished inverse delays are available for the I> stage. The
inverse delay types are described in chapter 2.29. The device
will show the currently used inverse delay curve graph on the
local panel display.
Inverse time limitation
The maximum measured secondary current is 50xIN. This
limits the scope of inverse curves with high pick-up settings.
See chapter 2.29 for more information.
Cold load and inrush current handling
See chapter 3.3.
Setting groups
There are two settings groups available for each stage.
Switching between setting groups can be controlled by digital
inputs, virtual inputs (mimic display, communication, logic)
and manually.
Figure 2.5-1 Block diagram of the three-phase overcurrent stage I>.
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