Schneider Electric PM5100 manual Synchronized demand, Block interval demand example

Chapter 8—Measurements and calculations PowerLogic™ PM5100 series user guide

The following illustration shows the different ways power demand is calculated using the block interval method. In this example, the interval is set to 15 minutes.

Block interval demand example

Calculation updates every 15 seconds

15-minute interval

15 30 45 60 . . .

Demand value is the average for the last completed interval

Time (sec)

Timed Sliding Block

		Demand value is
	Calculation updates at	the average for
	the end of the interval	the last
		completed
		interval
15-minute interval	15-minute interval	15-min
		Time
1 5	30	(min)
		45
	Timed Block

Calculation updates at the end of	Demand value is
the subinterval (5 minutes)	the average for
	the last
	completed
15-minute interval	interval

						Time
1 5			30			(min)
	20	25		35	40	45

Timed Rolling Block

Synchronized demand

You can configure the demand calculations to be synchronized using an external pulse input, a command sent over communications, or the device’s internal real-time clock.

•Command synchronized demand: This method allows you to synchronize the demand intervals of multiple meters on a communications network. For example, if a programmable logic controller (PLC) input is monitoring a pulse at the end of a demand interval on a utility revenue meter, you can 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 can choose Cmd Sync Block (command-synchronized block demand) or Cmd Sync Roll Block (command-synchronized rolling block demand). Cmd Sync Roll Blk requires that you specify a subinterval.

•Clock synchronized demand: This method allows you to synchronize the demand interval to the power meter’s internal real-time clock. This helps you synchronize the demand to a particular time, typically on the hour (for example, at 12:00 am). If you select another time of day when the demand intervals are to be synchronized, the time must be specified in minutes from midnight. For example, to synchronize at

64 © 2014 Schneider Electric All Rights Reserved