Sel 411L - Table 9.21 Energy Metering Quantities-(LINE)

P.9.36
SEL-411L Relay Protection Manual Date Code 20151029
Monitoring and Metering
Metering
View or Reset Demand Metering Information
The relay shows demand metering quantities and time-stamped peak demand
quantities when you use a communications port or
ACSELERATOR QuickSet
to view these quantities. In addition, you can read the demand and peak
demand quantities on the relay front-panel LCD screen.
To reset the demand metering values use the MET RD command from a
communications terminal, or use the RESET button in the
ACSELERATOR
QuickSet HMI > Meter and Control > Demand/Peak window, or answer
Y
and press ENT at the
Demand Submenu reset demand prompt on the front-panel
LCD screen. The relay begins the demand meter sampling period from the
time of the demand meter reset.
To reset the peak demand metering values, enter the MET RP command from
a communications terminal, or use the RESET button in the
ACSELERATOR
QuickSet HMI > Meter and Control > Demand/Peak window, or answer
Y
and press ENT at the
Demand Submenu reset peak demand prompt on the
front-panel LCD screen. You can also reset demand metering with Global
settings RST_DEM and RST_PDM (for demand and peak demand) when
EDRSTC (Data Reset Control) is Y.
Demand Metering Updating and Storage
The relay updates demand and peak demand values once per second. The
relay also stores peak demand values and the date and time these occurred to
nonvolatile storage once per day (it overwrites the previous stored value if it is
exceeded). Should the relay lose control power, it will restore the peak
demand information saved at 23:50 hours on the previous day.
Demand metering updating and peak recording is suspended during the time
that SEL
OGIC control equation FAULT asserts Relay Word bit DFAULT
(Delayed FAULT Suspend).
Energy Metering
Energy is the power consumed or developed in the electric power system
measured over time. You can use accurate accounting of power system energy
flow to manage billing revenues, whether your system is a net energy producer
or consumer. Time-synchronized demand and energy measurements make
demand and energy metering information even more useful for power system
status applications.
The relay integrates energy imported and exported on a per-phase basis every
second. As in demand metering, the relay uses the longer-term accumulations
of rms or true real power for reliable energy data. Also similar to demand
metering, energy metering is available only for the LINE data. Table 9.21 lists
the energy metering quantities that the relay displays.
Table 9.21 Energy Metering Quantities—(LINE)
Analog Quantity Units Description
MWHOUT MWh, primary Single-phase energy export
MWHIN MWh, primary Single-phase energy import
MWHT MWh, primary Single-phase energy total
3MWHOUT MWh, primary Three-phase energy export
3MWHIN MWh, primary Three-phase energy import
3MWH3T MWh, primary Three-phase energy total