12-5
IM 760301-01E
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12
App
Index
Specifications
12.4 Accuracy
Voltage and Current Accuracy
Item
Specifications
Accuracy
Conditions
(accuracy at 6 months)
Temperature: 23
±
5
°
C. Humidity: 30 to 75% RH. Input waveform: Sine wave. Common-mode
voltage: 0 V. Line filter: OFF.
λ
(power factor): 1. Crest factor: 3. After warm-up time has passed.
Wired condition after zero-level compensation or measurement range change. f is the frequency.
Frequency
Accuracy
±
(reading error + measurement range error)
DC
• Voltage input
0.05% of r 0.05% of range
• Current sensor input
• Current of a 30-A input element
from direct input
• Current of a 2-A input element
0.05% of r 0.05% of range + 2
µ
A
from direct input
0.1 Hz
≤
f < 30 Hz
0.1% of r 0.2% of range
30 Hz
≤
f < 45 Hz
0.03% of r 0.05% of range
45 Hz
≤
f
≤
66 Hz
• Voltage input
0.01% of r 0.03% of range
• Current sensor input
• Current of a 30-A input element from
direct input
• Current of a 2-A input element from
direct input at the 500 mA to 2 A range
• Current of a 2-A input element from
0.03% of r 0.05% of range
direct input at the 5 mA to 200 mA range
66 Hz < f
≤
1 kHz
0.03% of r 0.05% of range
1 kHz < f
≤
10 kHz
0.1% of r 0.05% of range
10 kHz < f
≤
50 kHz
0.3% of r 0.1% of range
50 kHz < f
≤
100 kHz
0.012
×
f% of r 0.2% of range
100 kHz < f
≤
500 kHz
0.009
×
f% of r 0.5% of range
500 kHz < f
≤
1 MHz
(0.022
×
f – 7)% of r 1% of range
* The unit of f in the read error equation is kHz.
•
Add 3% of range (reference value) to the above accuracy figure for the accuracy of the
waveform display data, Upk, and Ipk. However, for external sensor input, add 3% of range + 5
mV (reference value). The effective input range is within
±
300% of the range (within
±
600% of
the range if the crest factor is set to 6).
•
For temperature changes after zero level compensation or range change, add 50 ppm of
range/
°
C to the DC accuracy of the voltage.
•
For temperature changes after zero level compensation or range change, add the following
values to the DC accuracy of the direct current input.
•
2-A input element:
3
µ
A/
°
C
•
30-A input element:
0.2 mA/
°
C
•
For temperature changes after zero-level compensation or range change on the external current
sensor input, add 0.02 mV/
°
C to the DC accuracy of the external current sensor input.
•
For self-generated heat caused by current input on an AC input signal, add the following values
to the current accuracy.
•
2-A input element:
0.004
×
I
2
% of reading
•
30-A input element:
0.00002
×
I
2
% of reading
•
For self-generated heat caused by current input on a DC input signal, add the following values to
the current accuracy.
•
2-A input element:
0.004
×
I
2
% of r 6
×
I
2
µ
A
•
30-A input element:
0.00002
×
I
2
% of r 3
×
I
2
µ
A
I is the current reading (A). The influence from self-generated heat continues until the
temperature of the shunt resistor inside the WT3000 lowers even if the current input changes to
a small value.
•
When the data update interval is 50 ms, add 0.1% of reading to all accuracy figures.
•
When the data update interval is 100 ms, add 0.05% of reading to all accuracy figures.