Wimotec Ltd
Measuring and monitoring unit
Technical description
WIMO 6CP10
WM6CP10.EN001
Wimotec 24h support phone +358 (0)20 753 3264
9
Power
quadrant
Current
related to
voltage
Power
direction
cosfii Power
factor
+ inductive
Lags
Forward
+
+
+ capacitive
Leads
Forward
+
-
- inductive
Leads
Reverse
-
+
- capacitive
Lags
Reverse
-
-
2.3.3.
Harmonics and Total Harmonic Distortion
(THD)
The device calculates the THDs as percentage of the base
frequency for currents and voltages.
The device calculates the harmonics for phase currents and
phase voltages from the 2nd to the 15th order. (The 17
th
harmonic component will also be shown partly in the value of
the 15
th
harmonic component. This is due to the nature of
digital sampling.)
2.3.4.
Voltage interruptions
WIMO 6CP10 includes a simple function to detect and measure
voltage sags.
The function calculates the number of voltage interruptions
and the total time of the voltage interruptions within a period.
The period is based on the real time clock of the device. The
available periods are:
•
8 hours, 00:00 – 08:00, 08:00 – 16:00, 16:00 – 24:00
•
one day, 00:00 – 24:00
•
one week, Monday 00:00 – Sunday 24:00
•
one month, the first day 00:00 – the last day 24:00
•
one year, 1
st
January 00:00 – 31
st
December 24:00
After each period, the number of interruptions and the total
interruption time are stored as previous values. The
interruption counter and the total time are cleared for a new
period. The pre-previous values are overwritten.
The voltage interruption is based on the value of the positive
sequence voltage U
1
and a user given limit value U
1
<.
Whenever the measured U
1
goes below the limit, the
interruption counter is increased, and the total time starts
cumulating.
Shortest recognized interruption time is 40 ms. If the voltage-
off time is shorter it may be recognized depending on the depth
of the voltage dip, the ratio of the limit and the voltage value
before the dip.
