Schneider Electric PowerLogic PM5300 Series Dokumentacja Pobierz pdf (Strona 21)

63230-507-201A1 Power Meter 750

03/2007 Section 4—Metering

Demand Power Calculation Methods Demand power is the energy accumulated during a specified period divided

by the length of that period. How the power meter performs this calculation

depends on the method you select. To be compatible with electric utility

billing practices, the power meter provides the following types of demand

power calculations:

• Block Interval Demand

• Synchronized Demand

• Thermal Demand

The default demand calculation is set to sliding block with a 15 minute

interval. (You can set up the other demand power calculation methods only

through communications.)

Block Interval Demand In the block interval demand method, you select a “block” of time that the

power meter uses for the demand calculation. You choose how the power

meter handles that block of time (interval). Three different modes are

possible:

• Sliding Block. In the sliding block interval, you select an interval from 1

to 60 minutes (in 1-minute increments). The power meter displays the

demand value for the last completed interval.

• Fixed Block. In the fixed block interval, you select an interval from 1 to

60 minutes (in 1-minute increments). The power meter calculates and

updates the demand at the end of each interval.

• Rolling Block. In the rolling block interval, you select an interval and a

subinterval. The subinterval must divide evenly into the interval. For

example, you might set three 5-minute subintervals for a 15-minute

interval. Demand is updated at each subinterval. The power meter

displays the demand value for the last completed interval.

Figure 4– 1 illustrates the three ways to calculate demand power using the

block method. For illustration purposes, the interval is set to 15 minutes.

Demand Reactive Power, 3Ø Total

Last Complete Interval

Peak

0 to 3276.70 MVAR

Demand Apparent Power, 3Ø Total

Last Complete Interval

Peak

0 to 3276.70 MVA

Table 4– 2: Demand Readings (continued)

1 2 ... 16 17 18 19 20 21 22 23 24 25 26 ... 67 68

Brak uwag

Schneider Electric PowerLogic PM5300 Series Dokumentacja Strona 21