Rockwell Automation 1413-CAP-ME-PE Capacitor Bank Controller, Series C - Manual (Page 55)

Rockwell Automation Publication 1413-UM001D-EN-P - November 2010 55
Chapter
4
Operation
Introduction The capacitor bank controller gathers real- and reactive-power data by using one
or more PowerMonitor meters. The processor manipulates data in engineering
units of kVAR and kW. The unit does not directly control power factor, but
rather works to actively minimize imported and exported kVAR. The net result
of this philosophy indirectly controls power factor and minimizes voltage
excursions associated with excessive kVAR export.
The capacitor bank controller can accommodate up to four different utility feeds
and/or generators. Each feed requires an individual PowerMonitor 1000 meter.
The unit sums the kW and kVAR readings from each of the PowerMonitor 1000
meters to arrive at an aggregate kVAR so that a single capacitor bank could be
used to compensate several feeds simultaneously.
The traditional C/k ratio is not required for the capacitor bank controller
because we are working in engineering units within the processor.
Aggregate Power Factor is calculated and displayed by using this formula:
The PowerMonitor 1000 meter data is gathered over Ethernet by using the
MicroLogix 1400 controller.
Operating Modes Each capacitor step can be individually selected to on, off, or auto status. The
capacitor discharge-timer interlock is in effect in Manual mode to prevent
capacitor bank damage. In Auto mode, a step is available to any of the automatic
sequences described below. In the On or Off mode, a step is unavailable to any
automatic operating mode:
• Manual (mode = 0) – This mode disables all automatic operating modes.
Manual mode is the default configuration. All capacitor steps have a
default configuration of auto.
• FILO (mode = 1) – This mode of operation switches the capacitor steps
on and off in first-in, last-out (FILO) order. That is, the first step on is the
last step turned off. This is most useful when all the capacitor steps are of
similar sized.
PF
Aggregate
KW
Aggregate
KW
Aggregate
2
KVAR
Aggregate
2
+
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