Schneider Electric 4000 manual Scale Factors, Settings, Setpoint, Interface Scale Groups

63230-300-212			Chapter 6—Alarms
April 2001				Scale Factors
SCALE FACTORS	A scale factor is the multiplier expressed as a power of 10. For example, a
	multiplier of 10 is represented as a scale factor of 1, since 101=10; a multiplier
	of 100 is represented as a scale factor of 2, since 102=100. This allows you
	to make larger values fit into the register. Normally, you do not need to
	change scale factors. If you are creating custom alarms, you need to
	understand how scale factors work so that you do not overflow the register
	with a number larger than what the register can hold. When SMS is used to
	set up alarms, it automatically handles the scaling of pickup and dropout
	setpoints. When creating a custom alarm using the circuit monitor’s display,
	do the following:
	• Determine how the corresponding metering value is scaled, and
	• Take the scale factor into account when entering alarm pickup and dropout
	settings.
	Pickup and dropout settings must be integer values in the range of -32,767
	to +32,767. For example, to set up an under voltage alarm for a 138 kV
	nominal system, decide upon a setpoint value and then convert it into an
	integer between -32,767 and +32,767. If the under voltage setpoint were
	125,000 V, this would typically be converted to 12500 x 10 and entered as a
	setpoint of 12500.
	Six scale groups are defined (A through F). The scale factor is preset for all
	factory-configured alarms. Table 6–1lists the available scale factors for each
	of the scale groups. If you need either an extended range or more resolution,
	select any of the available scale factors to suit your need. Refer to “Changing
	Scale Factors” on page 191 in Appendix B—Using the Command
	Interface.
	Table 6–1: Scale Groups
	Scale Group	Measurement Range			Scale
					Factor
	Scale Group A—Phase Current	Amperes
		0–327.67 A			–2
		0–3,276.7 A			–1
		0–32,767 A			0 (default)
		0–327.67 kA			1
	Scale Group B—Neutral Current	Amperes
		0–327.67 A			–2
		0–3,276.7 A			–1
		0–32,767 A			0 (default)
		0–327.67 kA			1
	Scale Group C—Ground Current	Amperes
		0–327.67 A			–2
		0–3,276.7 A			–1
		0–32,767 A			0 (default)
		0–327.67 kA			1

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