GE Industrial Solutions Entellisys 5.0 User Manual - Manual (Page 54)

Metering 54
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4.8 Demand Metering Alarms
Demand alarms are designed to be used for demand indication and control and are only
available with the Flex Relay option.
4.8.1 Operation
16 separate Demand Alarms are available. Each has an Under Demand and Over Demand set
point. Each will generate different events and have separate control inputs in FlexLogic.
The demand is calculated on the three-phase sum for each relay using the sub-interval setting
and will start as soon as the Demand Alarm is enabled.
The calculated demand must enter the desired demand range before the demand alarm is
“armed.” Once armed, the Demand Alarm will go into pickup as soon as a demand subinterval
either exceeds the Over-Demand pickup or drops below the Under-Demand pickup setting. If it
remains in pickup for the configured delay time, it will alarm.
Powerflow Direction
Powerflow will change the direction and how the set points should be configured. In figure 4-13,
setpoint relationships are shown for both positive and negative powerflow situations.
Figure 4-13 Demand ranges for either positive or negative power flow
FlexLogic
Pickup, Operate and Dropout elements for each relay are available in FlexLogic.