Datasheet

Installation and Operation
 2010 Microchip Technology Inc. DS51915A-page 17
Figure 2-7 illustrates the error measurements in the frequency range of 48-52 Hz at
5A
RMS
current.
FIGURE 2-7: Errors vs. Line Frequency.
Line frequency compensation is a simplified solution and does not compensate for fre-
quencies in which harmonics exist. However, it significantly improves the overall
accuracy of the meter.
There is one drawback to using this method. As demonstrated, the signal will be atten-
uated a little more than it is when the HPF has a lower cutoff frequency. This extra
attenuation slightly increases the measurement errors at low currents in which mea-
surement is made more difficult because of the lower signal-to-noise ratio (SNR). In this
situation, the accuracy decrease is less than 0.1% and is considered acceptable.
-0.1
-0.08
-0.06
-0.04
-0.02
0
0.02
0.04
0.06
0.08
0.1
47 48 49 50 51 52 53
Frequency Line (Hz)
Error (%)
Error vs frequency