MI 2883 Energy Master
Theory and internal operation
139
Figure 5.11:Voltage dip related screens on the instrument
A voltage dip is characterized by following data:
Dip
Start time,
Level (
U
Dip
)
and
Dip
duration
:
U
Dip
– residual dip voltage, is the lowest
U
Rms(1/2)
value measured on any channel
during the dip. It is shown in
Level
column in the Event Table on the instrument.
The
Dip
Start time
is time stamped with the time of the start of the
U
Rms(1/2)
of the
channel that initiated the event. It is shown in
START
column in the Event Table
on the instrument. The Dip End time is time stamped with the time of the end of
the
U
Rms(1/2)
that ended the event, as defined by the threshold.
The
Dip Duration
is the time difference between the Dip Start time and the Dip
End time. It is shown in
Duration
column in the Event Table on the instrument.
Voltage swell
Standard compliance: IEC 61000-4-30 Class S (Sections 5.4.1 and 5.4.3)
The
Swell Threshold
is a percentage of nominal voltage defined in CONNECTION
menu. The swell threshold can be set by the user according to the use.
Swell
Hysteresis
is difference in magnitude between the Swell start and Swell end
thresholds. Instrument event evaluation in Event table screen depends on Connection
type:
On single-phase system (Connection type: 1W) , a voltage swell begins when the
U
Rms(1/2)
voltage rises above the swell threshold, and ends when the
U
Rms(1/2)
voltage is equal to or below the swell threshold plus the hysteresis voltage (
see
On poly-phase systems (Connection type: 2W, 3W, 4W, Open Delta) two
different view can be used for evaluation simultaneously:
o
Group view
with selected
ALL
INT
view: A swell begins when the
U
Rms(1/2)
voltage of one or more channels is above the swell threshold and
ends when the
U
Rms(1/2)
voltage on all measured channels is equal to or
below the swell threshold plus the hysteresis voltage.
o
Phase view Ph.: A swell begins when the
U
Rms(1/2)
voltage of one channel
rises above the swell threshold, and ends when the
U
Rms(1/2)
voltage is
equal to or below the swell threshold plus the hysteresis voltage, on the
same phase.
A voltage swell is characterized by following data:
Swell Start time,
Level (U
Swel
l
)
and
Swell duration
: