Schneider Electric HRB1684301-01 user manual Typical sources of test errors, Output is

PowerLogic™ PM5500 series user manual	Chapter 15—Verifying accuracy
Using the values from the above example, the maximum pulse constant for the digital
output is:
Kmax =	3600-----------------------------------------------------------------------------------------------------------------------× (digital output maximum pulse frequency)	= 3600-----------------------× 25
	Pmax	285.6

Kmax = 315.13 pulses per kWh

6.Set the pulse constant (K) to a value below Kmax (for example, 300 pulses/kWh), then calculate the new maximum output pulse frequency at Pmax:

New maximum pulse frequency =	K-----------------------× Pmax	=	300---------------------------------------------------------------------pulses/kWh × 285.6 kW
	3600		3600 seconds/hour
New maximum pulse frequency = 23.8		pulses/second = 23.8 Hz

7.Check the new maximum pulse frequency against the limits for the LED and digital outputs:

· ≤

23.8 Hz LED maximum pulse frequency (2.5 kHz)

· ≤

23.8 Hz digital output maximum frequency (25 Hz)

As expected, changing K to a value below Kmax allows you to use the digital output for energy pulsing.

8.Follow the procedure in “Energy pulsing” on page 80 to set the pulse constant (K) in the meter.

Typical sources of test errors

If excessive errors are observed during accuracy testing, examine your test setup and test procedures to eliminate typical sources of measurement errors:

•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.

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