Accuracy verification test points
The meter should be tested at full and light loads and at lagging (inductive) power factors to help ensure testing over the entire range of the meter.
The test amperage and voltage input rating are labeled on the meter. Refer to the installation guide or data sheet for your meter’s nominal current, voltage and frequency specifications.
Watt-hour test point | Sample accuracy verification test point |
---|---|
Full load | 100% to 200% of the nominal current, 100% of the nominal voltage and nominal frequency at unity power factor or one (1). |
Light load | 10% of the nominal current, 100% of the nominal voltage and nominal frequency at unity power factor or one (1). |
Inductive load (lagging power factor) | 100% of the nominal current, 100% of the nominal voltage and nominal frequency at 0.50 lagging power factor (current lagging voltage by 60° phase angle). |
VAR-hour test point | Sample accuracy verification test point |
---|---|
Full load | 100% to 200% of the nominal current, 100% of the nominal voltage and nominal frequency at zero power factor (current lagging voltage by 90° phase angle). |
Light load | 10% of the nominal current, 100% of the nominal voltage and nominal frequency at zero power factor (current lagging voltage by 90° phase angle). |
Inductive load (lagging power factor) | 100% of the nominal current, 100% of the nominal voltage and nominal frequency at 0.87 lagging power factor (current lagging voltage by 30° phase angle). |