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5.3 LCD SUB-MENU DISPLAYS
This section of the manual describes in greater detail some of the menu options introduced in the
previous section.
5.3.1 DISPLAY #1 Screen
This display contains real-time UPS operational values that are vital to the operation of the UPS.
Reverse video areas are titles whereas normal video areas contain status information. The top line
contains the current date and time. If no alarms exist, MESTA ELECTRONICS will appear in the center
of this line. If an alarm exists, this center portion will be replaced by a flashing message indicating what
type of alarm exists.
The left half of the screen below the 1
st
line contains status pertaining to the AC line. Either an ON or
OFF will exist next to the INPUT title, indicating whether or not the UPS is drawing power from the AC
line. ON is the normal operating mode of the UPS. If OFF is displayed, the STATUS line and the bottom
line of the display will indicate the reason why. VOLTS indicates the RMS line-to-line voltage (nominally
208 volts) of the utility (Vab, Vbc, and Vca for all three line-to-line voltages). AMPS indicates the current
drawn from each line and %RATED is the percentage of rated current being drawn from each line.
FREQ indicates the frequency of the utility voltage (nominally 60 Hz).
To the right of the AC line information is a similar block of information pertaining to the OUTPUT
(powering the load). The STATUS line under the OUTPUT indicates from where the output is derived.
This status normally indicates LINE (not flashing), indicating that the AC line utility is supplying the
power. Abnormal conditions such as ON INVERTER (indicating the batteries are supplying the output
power), ON LINE+INVERTER (indicating the AC line and the batteries are jointly supplying the output
power), and OFF (indicating the OUTPUT is off) are flashed so as to gain the attention of the operator.
VOLTS indicates the RMS line-to-line voltage (nominally 208 volts) of the output (Vab, Vbc, and Vca for
all three line-to-line voltages). AMPS indicates the current supplied by each phase to the load.
%RATED is the percentage of rated current being drawn from the UPS by the load. If any of these
numbers exceeds 100%, the system is being overloaded. Unless this situation is temporary such as in
inrush caused by powering up a load, adjustments should be made in the load to eliminate this
condition. Normally, the steady state value of all three of these %RATED values should be less than
85% to assure some margin. If one or two of the output lines are heavily loaded while the others are
not, it is probably wise to better distribute the load more evenly. FREQ in this portion of the display
indicates the frequency of the OUTPUT voltage (nominally 60 Hz).
The far right side of the display contains battery related data. VOLTS indicates the voltage of the
batteries. For a system containing twenty 12-volt batteries having a total nominal voltage of 240 volts,
this number will be approximately 274 volts when the batteries are fully charged. 274 represents the
float voltage applied to the batteries when they are fully charged. AMPS indicates the current coming
from the batteries. A negative number indicates the batteries are being charged. Once the batteries are
0 1 / 1 1 / 9 9 M E S T A E L E C T R O N I C S 1 6 : 5 2 : 1 1
_
I N P U T
_ O N
O U T P U T
_ L I N E
B A T T E R Y
S T A T U S =
V O L T S =
2 0 8 | 2 0 9 | 2 0 8 | 2 0 7 | 2 0 8 | 2 0 8 | 2 7 5
A M P S =
1 7 | 1 8 | 1 6 | 1 6 | 1 5 | 1 6 | + 0 . 0
% R A T E D =
5 2 | 5 5 | 4 9 | 5 8 | 5 5 | 5 8 |
C H A R G E
_
F R E Q =
6 0 . 0 0 | 6 0 . 0 0 1 0 0 %
