
B
Appendix B: Metering
B Metering
B.1 Accuracy
Table B.1 Metering Accuracies
Parameter |
| Range | Accuracy |
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rms Current (L & G) |
| ±1% of measurement from | ||||||
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| ±0.5% of In from 10- 50% of In | |
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Average rms Current |
| ±1% of measurement from | ||||||
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| ±0.5% of In from | |
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Ampere Demand per Phase | 0.. 250% In Displayed in Amperes | ±1% of measurement from | ||||||
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| ±0.5% of In from | |
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Average Ampere Demand | ±1% of measurement from | |||||||
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| ±0.5% of In from | |
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rmsVoltage | ±1% of measurement from | |||||||
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| ±0.5% of Vn from | |
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Average rms Voltage |
| ±1% of measurement from | ||||||
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| ±0.5% of Vn from | |
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Active Power (kW) |
| ±2% of measurement from | ||||||
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| ±0.1% of V | from |
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| n | n |
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kW Demand |
| ±2% of measurement from | ||||||
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| ±0.1% of V | from |
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| n | n |
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kW Hours |
| ±2% of measurement from | ||||||
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| ±0.1% of V | from |
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| n | n |
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Apparent Power (kVA) |
| ±2% of measurement from | ||||||
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| ±0.1% of V | from |
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| n | n |
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±2% of measurement from | ||||||||
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| ±0.1% of V | from |
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| n | n |
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kVAR Hours |
| ±2% of measurement from | ||||||
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| ±0.1% of V | from |
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| n | n |
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Power Factor |
| ±0.04 4 |
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Frequency |
| ±0.1% of reading providing voltage is 50% VT primary rating | ||||||
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1 Measured at PF=1. For PF<1, ±2% + angle error (±2% for PF≥0.7) |
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2 Measured at PF=0. For PF>0, ±2% + angle error (±2% for PF≤0.7) |
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3 Energy is accumulated in either kHR or MHR, selectable (parameter). |
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4 For power factor, 1 is considered “perfect,” negative is leading and positive is lagging. |
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5 P | n | = V | n | x I , where V | = VT rating (120 V) and I = CT rating (5A). |
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| n | n | n |
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Note for all values: Stated accuracy applies only when the device is not in pickup. These measurements are valid over a frequency range of 45- 65Hz and include fundamental, second harmonic, and all odd harmonics up to the 13th harmonic of the fundamental line frequency.
58 | Siemens Energy & Automation, Inc. |