CHAPTER 3: METERING
EPM 5100 ELECTRONIC POWER METER – USER GUIDE
3–3
The first press of any key while the EPM 5100 is in Metering mode illuminates the backlit
display, if it is not already lit. The display remains illuminated for 10 minutes after the last
key press.
3.1.6
Metering Accuracies
The EPM 5100 samples each of the voltage and current inputs 480 times per second to
calculate the values of the parameters listed in Table 1–2:
on page 1–4. The meter automatically scales the units and displays the results on the
LCD. The display is updated every three seconds. An example of a metering screen is
shown below. The metering accuracies for all functions are listed in the following table.
FIGURE 3–1: Sample Metering Screen
Table 3–1: Metering Accuracies
Function
Accuracy
Current (rms)
±0.25% of reading
Neutral current
±1.50% of reading
L-N voltage (rms)
±0.25% of reading
L-L voltage (rms)
±0.75% of reading
Watts
±0.5% of reading
Volt-amperes
±0.5% of reading
Power factor
±1.0% of reading
Energy
±0.5% of reading
Frequency
±0.5% of reading
