124 Rockwell Automation Publication 1560F-UM001A-EN-P - June 2019
Chapter 5 Metering
Power
Real, Reactive, and Apparent power calculations (along with demand and
maximum demand) are made on each line power phase along with a total for all
three phases.
The Energy parameters can be cleared using the Meter Reset parameter. See
Resetting Metering Parameters
on page 122 for further details.
The demand numbers are calculated as follows:
• Energy is calculated over a period of time defined by "Demand Period",
Parameter 290.
• The previous "n" period values are averaged and the result is written to the
Demand, Parameter 272, 281 and 288, which is used in calculating the
Max Demand values. This averaging uses a rolling window algorithm
where the previous "n" periods are averaged.
TIP For Reactive Energy, Parameter 278 and 279, the system will keep a:
• positive energy, which only integrates power when it is positive,
• negative energy, which only integrates power when it is negative, and
• net energy, which always integrates.
Table 29 - Metering Parameters Associated with Power
Parameter Number Name/Description Min/Max Value Default Value Access Units
269 Real Power A ±1000.000 0.000 R MW
270 Real Power B
271 Real Power C
10 Real Power
11 Real Energy ±1000.000 0.000 R MWH
272 Real Demand ±1000.000 0.000 R MW
273 Max Real Demand
274 Reactive Power A ±1000.000 0.000 R MVAR
275 Reactive Power B
276 Reactive Power C
277 Reactive Power
278 Reactive Energy C ±1000.000 0.000 R MVRH
279 Reactive Energy P
280 Reactive Energy ±1000.000 0.000 R MVRH
281 Reactive Demand ±1000.000 0.000 R MVAR
282 Max. Reactive Dmd
To Next Page
Loading...
Need help?
General
