4.12
SEL-734 Meter Instruction Manual Date Code 20090730
Metering
Demand Metering
View or Reset Demand Metering Information
Via Serial Port
See MET D (Demand Metering) on page 10.19. Use the MET D command to
display present demand and peak demand metering for the following values:
The MET R D command resets the demand metering values. The MET R P
command resets the peak demand metering values. The MET D P command
displays peak demand metering at the last MET R P command. The
MET D T command displays the values and times at which the peak demands
were set.
If using rolling demand, after resetting the demand values, there may be a
delay of up to two times the DMTC setting before the demand values are
updated.
Via Front Panel
The information and reset functions available via the previously discussed
serial port commands MET D, MET R D, MET R P, and MET D P are also
available via the front-panel pushbuttons. See Figure 11.3.
Via Remote Bits and DNP
Three settings allow configuration of remote bits to reset demand, peak
demand, or energy values in the SEL-734. Add a remote bit, RB01āRB16, to
the global settings RSTDEM, RSTPKDM, or RSTENGY to remotely reset
each value. A DNP master can now write a binary output corresponding to a
remote bit to reset values in the SEL-734. Optionally, add a remote analog
quantity, RA00āRA31, as a password.
For example set RSTPKDM := RB01 AND RA00=12345. Now, to reset the peak
demand value in the SEL-734, the DNP master writes a value of 12345 to
RA00 and asserts RB01 to force the SEL-734 to reset the peak demand value.
After resetting the value, the master should write a new value to RA00 to clear
the password.
Demand Metering
Updating and Storage
The SEL-734 updates demand values approximately every second.
The meter stores peak demand values to nonvolatile memory once every
minute (it overwrites the previous stored value if it is exceeded). Should the
meter lose control power, it will restore the peak demand values saved by the
meter during the last save to nonvolatile memory.
Currents I
A,B,C,N
Input currents (A primary)
Power MW
A,B,C
(P) Single-phase megawatts delivered/received
(Form 9 only)
MW
3P
(P) Three-phase megawatts delivered/received
MVAR
A,B,C
(Q) Four-quadrant single-phase megavars
(Form 9 only)
MVAR
3P
(Q) Four-quadrant three-phase megavars
MVA
A,B,C
(S) Single-phase megavoltamps delivered/received
(Form 9 only)
MVA
3P
(S) Three-phase megavoltamps delivered/received
Courtesy of NationalSwitchgear.com
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