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Entellisys Low-Voltage Switchgear
Section 8. Metering
Entellisys meets metering requirements for a wide
variety of customer needs, including:
• rms current and voltage
• energy, power, and power factor
• power demand
• harmonic data
There are four levels of metering available:
• Basic Metering for simple monitoring
• Expanded Metering for energy monitoring
• Demand Metering for measuring energy
consumption
• Harmonic Metering for waveform and
harmonic analysis
The displayed rms values are averages over 1 second
(i.e., 60 cycles fundamental for a 60 Hz power system)
as total rms values, including harmonics.
Basic Metering
The Basic Metering package is included with all
Entellisys systems. Basic Metering includes rms
current per phase (I
, I
, I
A
B
per phase. On three-phase, four-wire systems, the
PTs are wye connected and Entellisys provides
line-to-neutral (V
, V
, and V
A
B
V
, and V
) voltages. In three-wire systems, the PTs
BC
CA
are delta connected and only line-to-line voltages
are provided.
Basic Metering quantities are typically displayed
on the one-line diagram, if so configured. Figure
8.1 shows a one-line diagram that displays the
rms currents at each circuit breaker and the rms
voltages at the main bus.
Figure 8.1
One-line Diagram
, and I
) and rms voltage
C
N
) and line-to-line (V
C
AB
All metering data in the basic and optional levels
can be viewed by clicking on the circuit breaker of
interest in the one-line diagram, which displays a
screen similar to that shown in Figure 8.2. This screen
provides access to all information associated with the
selected circuit breaker via the navigation buttons.
Expanded Metering
Expanded Metering is the first level of optional
metering features in Entellisys. You select the
number of Expanded Metering packages in each
system, which can be from zero to the maximum
number of circuit breakers in the lineup. With this
selection, energy (usage and consumption), power,
and power factor can be precisely tracked for every
circuit breaker that has the function enabled. This
information may be useful in tracking facility
process variations, allocating utility costs, and
understanding energy costs.
The following quantities can be metered with this
option (note that per phase quantities are only
available for wye-connected systems) :
• Positive watt-hours, per phase and three phase total
• Negative watt-hours, per phase and three phase
,
total
• Positive varhours, per phase and three phase total
• Negative varhours, per phase and three phase total
• Apparent voltamperehours, per phase and three
phase total
• Real power (watts) per phase and three phase total
• Reactive power (vars) per phase and three phase
total
• Apparent power (voltamperes) per phase and
three phase total
Figure 8.2
Circuit Breaker Status Screen
41
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