Rockwell Automation 1408-EMxx PowerMonitor 1000 Unit - Manual (Page 33)

Rockwell Automation Publication 1408-UM001D-EN-P - September 2013 33
PowerMonitor 1000 Unit Features Chapter 2
Metered Parameters
The power monitor calculates and returns the following demand values:
• Real power demand, kW
• Reactive power demand, kVAR
• Apparent power demand, kVA
• Demand power factor, percent lagging (-) or leading (+)
• Projected kW, kVAR, and kVA demand
• Demand interval elapsed time, minutes
Projected demand calculates a linear projection of demand at the end of a demand
interval.
Demand power factor is calculated using the following formula.
kW Demand / kVA Demand
Setup
Demand metering requires basic analog input setup as well as demand calculation
setup. Basic demand set-up parameters are found in the Advanced Setup menu.
Network demand synchronization is available on units connected to an Ethernet
network. Network-demand synchronization set-up parameters are found in the
Ethernet communication set-up menu.
Parameter Description Range Default User
Setting
Demand Source
(advanced setup)
Selects the source of the demand end-of-interval (EOI) signal.
0 = Internal Timer
1 = Status Input 2
2 = Controller Command
3 = Ethernet Demand Broadcast
Network-demand synch options are available only on units with an optional Ethernet
network installed.
• If Demand Broadcast Master Select is set to master then a Demand Source value
of 0…2 selects the EOI source that is used to trigger the demand-synch master
broadcast.
• If Demand Broadcast Master Select is set to slave then a Demand Source value of
0…3 selects the EOI source.
0…3 0
Demand Period
Length (advanced
setup)
Specifies the period for demand calculations. The following include special cases.
Demand source = 0 (internal time) and demand period length = 0 then demand
metering is disabled
Demand source 0 and demand period length = 0 then projected demand is disabled
Demand source 0 and demand period length 0 then projected demand is calculated
using the unit’s internal clock
0…99 min 15 min
Number of
Demand Periods
(advanced setup)
Specifies the number of demand periods to average together for demand
measurement. This parameter is used for sliding window demand calculations. For
example, for a 30 minute sliding-window, demand period length = 2 minutes and
number of demand periods = 15.
1…15 1