Instruction Manual

Chapter 2 Operating the EM720
Billing and Energy Metering
EM720 Power Quality and Revenue Meter 19
Energy Counters
The EM720 provides instrumentation energy and billing
energy metering. Both use the same energy measurement
circuitry as a source input for accumulation energies but
operate independently.
Energy counters have a nine-digit kWh resolution with one
decimal place by default. You can set the energy counters to
have fewer digits by changing the default energy roll value in
your meter (see Device Options and Mode Control
in Chapter
5).
Billing energy registers have the same resolution as
instrumentation energy counters.
Billing Energy Registers
The EM720 has 10 fully programmable billing energy
registers that can be linked to any internal energy source or
to any external pulse source that delivers pulses through the
device digital inputs.
Any of energy registers can provide either a single-tariff
energy accumulation or be individually linked to the TOU
system providing both total and multi-tariff energy billing.
See Configuring Billing/TOU
in Chapter 5 on how to configure
the meter billing registers and tariff schedule for your
application.
Maximum Demand Registers
Any of billing energy registers can be individually linked to
the maximum demand and cumulative maximum demand
registers providing the same demand tariff structure as you
selected for energy registers.
Tariff Rates
The EM720 provides three options for switching tariff rates:
• automatic via a programmable TOU calendar schedule
• external via communications by direct writing a tariff
number to the meter tariff register
• external via digital inputs by providing a tariff number
code on the meter tariff inputs
See Device Options and Mode Control
in Chapter 5 on how to
program the tariff control mode and select tariff inputs in
your meter.
The meter tariff structure supports 8 different tariff rates
using an arbitrary tariff schedule.
The EM720 TOU calendar provides a season tariff schedule
and an option for scheduled daylight savings switch dates. A
total of 4 types of days and 4 seasons are supported with up
to eight tariff changes per day. See Configuring Billing/TOU
for more information on programming the tariff calendar
schedule in your meter.