GE Industrial Solutions Entellisys System User Manual - Manual (Page 31)

Basic metering 31
4
4 Metering
Entellisys provides a number of metering quantities, including RMS current and voltage,
demands, energy values, power factors, and harmonic data. There are four levels of metering
available: basic metering, expanded metering, demand metering, and advanced metering.
4.1 Basic metering
Basic metering is always available in Entellisys (i.e., it is not an optional feature). Basic metering
includes RMS current per phase (I
A
, I
B
, I
C
and I
N
) and RMS voltage per phase. For wye PTs,
Entellisys provides line-to-neutral (V
A
, V
B
and V
C
) and line-to-line (V
AB
, V
BC
and V
CA
) voltages. For
delta PTs, Entellisys provides line-to-line voltages only.
The RMS voltages and currents are averages over one second (nominally 60 cycles of the
fundamental power system frequency at 60 Hz) and include harmonics.
4.2 Expanded metering
Expanded metering (also referred to as detailed metering) is an optional feature in Entellisys.
Expanded metering can be enabled for each circuit breaker, up to the maximum number of
purchased expanded metering options. With the expanded metering option enabled, Entellisys
provides the following quantities:
• Positive watt-hours, per phase and total
• Negative watt-hours, per phase and total
• Positive var-hours, per phase and total
• Negative var-hours, per phase and total
• Apparent VA-hours, per phase and total
• Real power (watts) per phase and total
• Reactive power (vars) per phase and total
• Apparent power (VA) per phase and total
• Power factor per phase and total
• Minimum power factor, including date and time, per phase and total
• Maximum power factor, including date and time, per phase and total
Per phase quantities are only available for wye connected systems.
Watt-hours, var-hours, and VA-hours are sums starting from when the option was last applied,
or since the last time the values were reset through the HMI.
Real, reactive, and apparent power quantities are averages over one second (nominally
60 cycles of the fundamental power system frequency at 60 Hz) and include harmonics. Power
factors are calculated by dividing real power by apparent power.