Schneider Electric HRB1684301-01 user manual Test points, Energy pulsing considerations

PowerLogic™ PM5500 series user manual Chapter 15—Verifying accuracy

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 Schneider Electric representative.

Related topics

•See “Typical sources of test errors” on page 133 for possible causes of test errors.

•See “Power, energy and power factor” on page 135 for information on how the meter calculates power factor.

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.

Watt-hour test points example

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	100% of the nominal current, 100% of the nominal voltage and nominal frequency
power factor)	at 0.50 lagging power factor (current lagging voltage by 60° phase angle).

Var-hour test points example

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	100% of the nominal current, 100% of the nominal voltage and nominal frequency
power factor)	at 0.87 lagging power factor (current lagging voltage by 30° phase angle).

Energy pulsing considerations

The meter’s alarm / energy LED and digital outputs are capable of energy pulsing within the following limits:

Energy pulsing limits

Description	Alarm / energy LED	Digital output
Maximum pulse frequency	2.5 kHz	25 Hz
Minimum pulse constant	1 pulse per kWh
Maximum pulse constant	9,999,999 pulses per kWh

The pulse rate depends on the voltage, current and PF of the input signal source, the number of phases, and the VT and CT ratios.

If Ptot is the instantaneous power (in kW) and K is the pulse constant (in pulses per kWh), then the pulse period is:

Pulse period (in seconds) =	3600	=	1
	K-------------------× Ptot		Pulse--------------------------------------------------frequency (Hz)

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