UNIPOWER
UP-2210R/P Hardware installation and configuration manual
72
A voltage sag (or swell) recording begins when the voltage one of the phases U1-U3 passes the Uref value +/-
the trig level as in
Figure 76
(1). The recording will have the timing as described above.
The
duration
of the sag/swell event is calculated to the point where the voltage of all phases U1-U3 is back
within the trig level + the
hysteresis
value as in
Figure 76
(2) in accordance to IEC 61000-4-30 Class A.
The purpose of the hysteresis level is to avoid recording secondary events that occur directly following an
important sag/swell. The meter also calculates the
depth
of the sag/swell as the lowest (sag) or highest (swell)
voltage value during the event. This value is expressed as the residual voltage level in accordance to IEC
61000-4-30 Class A.
If the nominal level in the system is changing, for example in high voltage networks, you can use a
sliding
reference
nominal level (see
Figure 76
). The recorder will calculate the average value of the reference
voltage channel (U1) according to the norm IEC 61000-4-30 and create its own reference level. The value of
the sliding reference level will be shown along with each sag/swell.
Normally, if sliding reference is not active, the fixed reference value is used as the nominal voltage.
b) U4 trig level [V]
If the voltage on channel U4 is higher or lower than the reference value +/- the trig level a sag/swell recording
starts.
c) Voltage sum trig level [V]
This trig gives you the possibility to trig on earth faults. Normally the voltage sum U1+U2+U3=0. If this is
not the case you probably have an earth fault and this trigger starts a recording.
Current triggers
a) I1-I3 high trigger
Whenever one of the current phases I1-I3 exceeds the trig level a sag/swell recording starts as described
above. For current you also have the possibility to specify Hysteresis in accordance to the IEC 61000-4-30
norm. In this case the hysteresis is specified as a current value and is added to the trig level. By specifying a
hysteresis level you avoid recording secondary events that occur directly following an important current trig
event.
b) I4 trig level [A]
If the current on I4 exceeds the trig level a sag/swell recording is started.
c) Earth fault trig trig level [A]
This trig gives you the possibility to trig on earth faults. Earth faults are detected by calculating the sum of the
currents. Normally the current sum I1+I2+I3+I4=0. If this is not the case you probably have an earth fault and
this trigger starts a recording.
On high voltage systems you don’t have a neutral conductor and normally don’t use channel I4. In this case,
select 0 as constant on channel I4 (see
Figure 65
) and this trigger will work as intended anyway.
d) Earth fault reference level type
With setting fixed reference the earth fault trig compares the actual current to 0 Amps and trigs when current
is higher than the trig level (c). With setting sliding reference the earth fault trig compares the actual current to
a sliding mean current value and trigs when difference is larger than the trig level (c). This is useful if there is
an offset (starting) value for the current sum and you want to trig on small deviations from this level. The
offset could be because of current unbalance. The sliding reference is a mean value calculated over 1 minute.
