Schneider Electric 4000 manual Demand Current, Demand Voltage, Block Interval Demand on

63230-300-212	Chapter 4—Metering Capabilities
April 2001	Demand Readings

Synchronized Demand

Demand Current

The demand calculations can be synchronized by accepting an external pulse input, a command sent over communications, or by synchronizing to the internal real-time clock.

•Input Synchronized Demand. You can set up the circuit monitor to accept an input such as a demand synch pulse from an external source. The circuit monitor then uses the same time interval as the other meter for each demand calculation. You can use any digital input installed on the meter to receive the synch pulse. When setting up this type of demand, you select whether it will be input-synchronized block or input- synchronized rolling block demand. The rolling block demand requires that you choose a subinterval.

•Command Synchronized Demand. Using command synchronized demand, you can synchronize the demand intervals of multiple meters on a communications network. For example, if a PLC input is monitoring a pulse at the end of a demand interval on a utility revenue meter, you could program the PLC to issue a command to multiple meters whenever the utility meter starts a new demand interval. Each time the command is issued, the demand readings of each meter are calculated for the same interval. When setting up this type of demand, you select whether it will be command-synchronized block or command-synchronized rolling block demand. The rolling block demand requires that you choose a subinterval. See Appendix B—Using the Command Interface on page 181 for more information.

•Clock Synchronized Demand. You can synchronize the demand interval to the internal real-time clock in the circuit monitor. This enables you to synchronize the demand to a particular time, typically on the hour. The default time is 12:00 am. If you select another time of day when the demand intervals are to be synchronized, the time must be in minutes from midnight. For example, to synchronize at 8:00 am, select 480 minutes. When setting up this type of demand, you select whether it will be clock-synchronized block or clock-synchronized rolling block demand. The rolling block demand requires that you choose a subinterval.

The circuit monitor calculates demand current using the thermal demand method. The default interval is 15 minutes, but you can set the demand current interval between 1 and 60 minutes in 1-minute increments.

Demand Voltage	The circuit monitor calculates demand voltage. The default voltage demand
	mode is thermal demand with a 15-minute demand interval. You can also set
	the demand voltage to any of the block interval demand modes described in
	“Block Interval Demand” on page 57.

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