Novatech Bitronics M87X Series, Manual

Page: 55 / 184

ML0021 August 15, 2018
39
Copyright 2018 Bitronics, LLC
4.7.3 Power Demands (Total Watts, VARs, and VAs)
Present Total Watt, VAR, and VA Demands are calculated via the instantaneous
measurement data. The Total VA Demand calculation type is based on the instantaneous
Total VA calculation type (Section 4.4)
Upon power-up, all Present Total Watt, VAR, and VA Demands are reset to the average of
the stored Maximum and Minimum values. The Maximum and Minimum Demands are
initialized to the minimum and maximum values recalled from non-volatile memory. Upon
a demand reset, the Maximum and Minimum Demands are set equal to the Present Total
Watt, VAR, and VA Demand values. A demand reset does not change the value of the
Present Total Watt, VAR, and VA Demands.
4.7.4 Voltage THD Demand
Present Voltage THD Demands are calculated via the instantaneous measurement data
used to calculate the per-phase and phase-to-phase Voltage THDs (Section 4.8.1).
Voltage THDs are calculated for both Bus 1 and Bus 2. By applying a thermal demand to
the THD measurement, the M87x provides a more effective method of determining the
severity of a harmonic problem.
Upon power-up, all Present Voltage THD Demands are reset to zero. Maximum Voltage
THD Demands are initialized to the maximum values recalled from non-volatile memory.
Upon Harmonic Demand Reset, all per-phase Present and Maximum Voltage THD
demands are set to zero.
4.7.5 Current TDD Demand
Present Current TDD Demands are calculated via the instantaneous measurement data.
By applying a thermal demand to the TDD measurement, the M87x provides a more
effective method of determining the severity of a harmonic problem.
Upon power-up, all Present Current TDD Demands are reset to zero. Maximum Current
TDD Demands are initialized to the maximum values recalled from non-volatile memory.
Upon Harmonic Demand Reset, all per-phase Present and Maximum Current TDD
demands are set to zero.
4.7.6 Demand Resets
The demand values are reset in four groups: current, voltage, power, and harmonics. This
can be accomplished via a network and protocol (refer to the specific protocol manual for
details).
4.7.7 Demand Interval
The M87x uses 15 minutes as the default demand interval, however it can be changed.
Four separate, independent demand intervals may be set for current, voltage, power, and
harmonics. The range of demand intervals is 5 to 3600 seconds (1hr). This can be
accomplished via a network and protocol (refer to the specific protocol manual for details)
or by using the 70 Series Configurator. While the Demand Interval is stored internally as a