Operation Techniques
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defines tariff change points per day indicating the beginning of the new tariff. When
a tariff becomes active, the
TOU
system connects its cumulative and demand
keeping registers to prescribed inputs, so they will accumulate measured energy and
store extreme demands during the entire tariff period.
The currently active tariff and profile numbers are accessible via communications,
and can be used to trigger a setpoint.
For appropriate
TOU
system operation, the user must configure the
TOU
calendar
and the daily profiles used, and to specify inputs for the
TOU
accumulating energy
and demand registers. All the
TOU
system accumulating and configuration registers
are accessible only via communications.
NOTE
Daylight savings time is not considered. The user should manually perform time update in
the instrument at an appropriate date before daylight savings time becomes effective, and
at daylight savings time ending.
4.7.2 TOU System Registers
Accumulating Energy Registers
Energy measurements are provided for eight energy
sources with a set of 8
accumulating energy registers
×
16 tariffs. Each of the energy registers, can be
configured to accumulate kWh, kvarh, kVAh (imported, exported, net, or total)
measured by the Powermeter, or to accumulate energy measured by external energy-
counting meters.
All the
TOU
system accumulating energy registers can be cleared simultaneously via
the front panel, communications, or by a programmable setpoint.
Demand Registers
Three demand registers are provided for keeping minimum/maximum demands
during each tariff period. Each demand register can be configured to store kW, kvar
or kVA demand, calculated using either measurement technique provided by the
PM295
: block interval, sliding window, or thermal demand.
All the
TOU
system demand registers can be cleared simultaneously via the front
panel, communications, or by a programmable setpoint.
