Rockwell Automation 1426 PowerMonitor 5000 Unit - Manual (Page 64)

64 Rockwell Automation Publication 1426-UM001F-EN-P - November 2013
Chapter 4 Metering
Instantaneous
The power monitor computes instantaneous demand by substituting the elapsed
interval duration for the total interval duration (T) in the demand equation. It is
therefore identical to the standard computation except it integrates the power
only over the elapsed interval duration and calculates the average value over the
elapsed duration. The modified equation thus becomes:
(t2 - t1) = Elapsed interval duration and is less than T
First Order Projection
The first order demand projection does the following:
• Uses the instantaneous demand as a starting point
• Computes the trend of the instantaneous demand
• Computes the time remaining in the interval
• Performs a first order projection of what the final demand is at the end of
the interval
This method can be useful where your system has a significant base load with
additional loads that are switched in and out during the interval.
Setup
Basic Metering and Date and Time setup are required. If the default demand
configuration (15-minute fixed interval based on internal clock) satisfies your
demand metering requirements, you do not need to change any demand setup
parameters.
If you want to customize the demand calculation to match that of your electric
service provider, or to satisfy other application requirements, then there are two
groups of setup parameters you can change.
Basic demand set-up parameters are found in the Metering_Basic tab under the
Configuration tab.
Demand_Source
Selects the source of the demand end-of-interval (EOI) signal. These are the
values:
0 = Internal Timer (default)
1 = Status Input 2
2 = Controller Command (Unit must be set up as a demand sync master)
3 = Ethernet Demand Broadcast