9410 series
Verifying accuracy
Round the number up to the nearest integer: Number of pulses = 9
Percentage error calculation for accuracy verification testing
Accuracy verification testing requires you to calculate the percentage error between
the meter being tested and the reference/standard.
Calculate the percentage error for every test point using the following formula:
Energy error = (EM - ES) / ES x 100%
Where:
•
EM = energy measured by the meter under test
•
ES = energy measured by the reference device or energy standard.
NOTE:
If accuracy verification reveals inaccuracies in your meter, they may be caused
by typical sources of test errors. If there are no sources of test errors present, please
contact your local Siemens Industry representative.
Typical sources of test errors
If you see excessive errors during accuracy testing, examine your test setup and test
procedures to eliminate typical sources of measurement errors.
Typical sources of accuracy verification testing errors include:
•
Loose connections of voltage or current circuits, often caused by worn-out contacts
or terminals. Inspect terminals of test equipment, cables, test harness and the
meter under test.
•
Meter ambient temperature is significantly different than 23 °C (73 °F).
•
Floating (ungrounded) neutral voltage terminal in any configuration with
unbalanced phase voltages.
•
Inadequate meter control power, resulting in the meter resetting during the test
procedure.
•
Ambient light interference or sensitivity issues with the optical sensor.
•
Unstable power source causing energy pulsing fluctuations.
•
Incorrect test setup: not all phases connected to the reference device or the energy
standard. All phases connected to the meter under test should also be connected to
the reference meter/standard.
•
Moisture (condensing humidity), debris or pollution present in the meter under test.
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 sheet or data sheet for your meter’s nominal current, voltage and frequency
specifications.
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7EN05-0336-01