Schneider Electric HRB1684301-01 user manual Current demand, Predicted demand, Thermal demand

PowerLogic™ PM5500 series user manual Chapter 12—Measurements and calculations

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 8:00 am, select 480 minutes. When setting up this type of demand, you can choose Clock Sync Block (clock-synchronized block demand) or Clock Sync Roll Blk (clock-synchronized rolling block demand). Clock Sync Roll Blk requires that you specify a subinterval.

Thermal demand

Thermal demand calculates the demand based on a thermal response, which imitates the function of thermal demand meters. The demand calculation updates at the end of each interval. You can set the demand interval from 1 to 60 minutes (in 1-minute increments).

The following illustration shows the thermal demand calculation. In this example, the interval is set to 15 minutes.

Thermal demand example

The interval is a window of time that moves across the timeline

99%

90%

% of Load

0%

15-minute	next
	15-minute
interval
	interval

Last completed demand interval

Time

(minutes)

Calculation updates at the end of each interval

Current demand

The power meter calculates current demand using one of the methods described in “Power demand calculation methods” on page 111. You can set the demand interval from 1 to 60 minutes in 1-minute increments (for example, 15 minutes).

Predicted demand

The power meter calculates predicted demand for the end of the present interval for kW, kVAR, and kVA demand. This prediction takes into account the energy consumption so far within the present (partial) interval and the present rate of consumption.

Predicted demand is updated every second.

The following illustration shows how a change in load can affect predicted demand for the interval. In this example, the interval is set to 15 minutes.

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