Schweitzer Engineering Laboratories SEL-351 - View or Reset Demand Metering Information; Via Front Panel; Via Serial Port; Demand Metering Updating and Storage

8-28 Breaker Monitor, Metering, and Load Profile Functions Date Code 20001006
SEL-351 Instruction Manual
View or Reset Demand Metering Information
Via Serial Port
See MET Command (Metering Data), MET D – Demand Metering in Section 10: Serial Port
Communications and Commands. The MET D command displays demand and peak demand
metering for the following values:
Currents I
A,B,C,N
Input currents (A primary)
I
G
Residual ground current (A primary; IG =3I0 = IA + IB + IC)
3I
2
Negative-sequence current (A primary)
Power MW
A,B,C
Single-phase megawatts (wye-connected voltages only)
MVAR
A,B,C
Single-phase megavars (wye-connected voltages only)
MW
3P
Three-phase megawatts
MVAR
3P
Three-phase megavars
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 in Section 11: Front-Panel Interface.
Demand Metering Updating and Storage
The SEL-351 Relay updates demand values approximately every 2 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 SELOGIC Control
Equation setting FAULT is asserted (= logical 1). See the explanation for the FAULT setting in
the following Maximum/Minimum Metering subsection.
ENERGY METERING
View or Reset Energy Metering Information
Via Serial Port
See MET Command (Metering Data), MET E – Energy Metering in Section 10: Serial Port
Communications and Commands. The MET E command displays accumulated single- and three-
phase megawatt and megavar hours. The MET RE command resets the accumulated single- and
three-phase megawatt and megavar hours.
Courtesy of NationalSwitchgear.com