B

Appendix B: Metering

B Metering

B.1 Accuracy

Table B.1 Metering Accuracies

Parameter

 

Range

Accuracy

 

 

 

 

 

rms Current (L & G)

 

0-250% In Displayed in Amperes

±1% of measurement from 50-125% of In

 

 

 

 

 

 

 

±0.5% of In from 10- 50% of In

 

 

 

 

Average rms Current

 

0-250% In Displayed in Amperes

±1% of measurement from 50-125% of In

 

 

 

 

 

 

 

±0.5% of In from 10-50% of In

 

 

 

Ampere Demand per Phase

0.. 250% In Displayed in Amperes

±1% of measurement from 50-125% of In

 

 

 

 

 

 

 

±0.5% of In from 10-50% of In

 

 

 

Average Ampere Demand

0-250% In Displayed in Amperes

±1% of measurement from 50-125% of In

 

 

 

 

 

 

 

±0.5% of In from 10-50% of In

 

 

 

rmsVoltage (L-L and L-N)

10-125% Vn Displayed in kV

±1% of measurement from 50-125% of Vn

 

 

 

 

 

 

 

±0.5% of Vn from 10-50% of Vn

 

 

 

 

Average rms Voltage

 

10-125% Vn Displayed in kV

±1% of measurement from 50-125% of Vn

 

 

 

 

 

 

 

±0.5% of Vn from 10-50% of Vn

 

 

 

 

Active Power (kW)

 

0-999,999.99 kW

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 5

 

 

 

 

 

 

 

n

n

 

 

 

 

kW Demand

 

0-999,999.99 kWD

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 5

 

 

 

 

 

 

 

n

n

 

 

 

 

kW Hours

 

0-999,999.99 kWHR

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 3, 5

 

 

 

 

 

 

 

n

n

 

 

 

 

Apparent Power (kVA)

 

0-999,999.99 kVA

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 5

 

 

 

 

 

 

 

n

n

 

 

 

Volt-Amperes Reactive (kVAR)

0-999,999.99 kVAR

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 2, 5

 

 

 

 

 

 

 

n

n

 

 

 

 

kVAR Hours

 

0-999,999.99 kVARH

±2% of measurement from 50-125% of Pn

 

 

 

 

 

 

 

±0.1% of V

from 10-50% of P 1, 2, 3, 5

 

 

 

 

 

 

 

n

n

 

 

 

 

 

Power Factor

 

-1- 0-+1

±0.04 4

 

 

 

 

 

Frequency

 

45-65 Hz

±0.1% of reading providing voltage is 50% VT primary rating

 

 

 

 

1 Measured at PF=1. For PF<1, ±2% + angle error (±2% for PF≥0.7)

 

 

2 Measured at PF=0. For PF>0, ±2% + angle error (±2% for PF≤0.7)

 

 

3 Energy is accumulated in either kHR or MHR, selectable (parameter).

 

 

4 For power factor, 1 is considered “perfect,” negative is leading and positive is lagging.

 

5 P

n

= V

n

x I , where V

= VT rating (120 V) and I = CT rating (5A).

 

 

 

 

n

n

n

 

 

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.

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Siemens SG8158-00 manual Appendix B Metering, Accuracy