VAMP 257, Operation And Configuration Instructions

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VAMP Ltd Feeder and motor manager
Technical description
VAMP 257
VM257.EN002 VAMP 24h support phone : +358 (0)20 753 3264
37
&
t
&
&
>
t
s
t
r
MA X
Istlohko
Motor nom .
start current
Delay Definite / inverse
time E nable events Inverse delay
Start
T ri p
Re g ister
event
Re g ister
event
Im1
Im2
Im3
B lock
Figure 2.3.8-2. Block diagram of the stall protection stage I
st
>.
Parameters of the stall protection stage:
Ist> (48)
Parameter Value/unit Description
ImotSt xImot
Nominal motor starting
current
Ist> %Imot Motor start detection current.
Must be less than initial motor
starting current.
DT Operation charact./ definite
time
Type
Inv Operation charact./ inverse
time
tDT> s Operation time [s]
Setting
values
tInv> s Time multiplier at inverse
time
SCntr Start counter (Start) reading
TCntr Trip counter (Trip) reading
Flt x Imot Max. value of fault.
Recorded
values
EDly % Elapsed time as compared to
the set operate time, 100% =
tripping
2.3.9. Frequent start protection (66)
NOTE! This function is available only in motor protection mode.
The simplest way to start an asynchronous motor is just to
switch the stator windings to the supply voltages. However
every such start will heat up the motor considerably because
the initial currents are significantly above the rated current.
If the motor manufacturer has defined the maximum number of
starts within on hour or/and the minimum time between two
consecutive starts this stage is easy to apply to prevent too
frequent starts.
When current has been less that I
stop
and then exceeds I
StartMin
the situation is recognized as a start. The maximum current for
a stopped motor I
stop
is 10 % x I
mot
. The minimum current for a
just started motor I
StartMin
is 150 % x I
mot
.