Schweitzer Engineering Laboratories SEL-311C - Demand Metering Updating and Storage

8.27
Date Code 20060320 Instruction Manual SEL-311C Relay
Breaker Monitor and Metering Functions
Demand Metering
The MET RD command resets the demand metering values. The MET RP
command resets the peak demand metering values.
Via Front Panel
The information and reset functions available via the previously discussed
serial port commands MET D, MET RD, and MET RP are also available via
the front-panel {METER} pushbutton. See Figure 11.2.
Demand Metering
Updating and Storage
The SEL-311C updates demand values approximately every two seconds.
The relay stores peak demand values 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 values saved by the relay at
23:50 hours on the previous day.
Demand metering updating and peak recording is momentarily suspended
when SEL
OGIC control equation setting FAULT is asserted (= logical 1). See
the explanation for the FAULT setting in Maximum/Minimum Metering
Updating and Storage on page 8.29.
MW
3P
Three-phase megawatts
MVAR
3P
Three-phase megavars