Siemens MJ-5 Installation And Operation Manual page 12

2 Using the MJ-5 Operator Panel and Controls
remote operator can only view the status of the control
panel. Only a local operator can change the Remote control
status by using the Remote/Local push-button.
Band Indicator LEDs
Three Band Indicators, "High", "In Band," and "Low," are
located at the top of the front panel. The microprocessor
continuously compares load voltage (corrected for line
drop) against the Voltage Level and Bandwidth set points.
The Band Indicator LEDs show the results of this
comparison (see Table 2.2).
"In Band" indicates that regulator output voltage is within
voltage and bandwidth set points.
"High" indicates that regulator output voltage is out-of-
limits on the high side.
"Low" indicates that regulator output voltage is out-of-
limits on the low side.
In all power flow modes except Neutral Reverse, if one of
the three Band Indicators is flashing, it is an indication that
tap changes are being inhibited by the control program. In
Neutral Reverse, the flashing Band Indicator in conjunction
with a Reverse Power Flow condition may mean that the
control program is returning the tap position to Neutral.
Table 2.2 Band Indicator Status
Power Flow
Mode
RPF active and
current
magnitude
exceeds I
Threshold %
Neutral R Flash
Idle R Flash
Co-Gen On solid
BI-Dir On solid
F Lock Flash
R Lock On solid
In the above table, the indicator that is flashing or is on
solid is the respective Band Indicator (High, Low, or In
Band). If all band indicators are off, it is an indication that
Voltage Limit Control (VLC) is active and compensated
regulator output voltage is either higher than the VLC
upper limit, or lower than the VLC Lower limit.
Siemens Industry, Inc.
Band Indicator Status
FPF active and
RPF or FPF
with current current
magnitude < magnitude
I Threshold %, exceeds I
but not = 0 Threshold %
Flash On solid
Flash On solid
Flash On solid
Flash On solid
On solid On solid
On solid Flash
Figure 2.2 Band Indicators and VLC Indicators
Raise / Lower LED Indicator
As a default, the Raise / Lower indicator is continuously
illuminated when the tap changer motor is raising or
lowering the tap position. However, the Raise / Lower
indicator can be configured to flash when the tap changer
motor is lowering the tap position. This is accomplished by
choosing the Lower LED setting under the <ADV
CONFIGURE> menu.
Voltage Limit Control LED Indicators
The Voltage Limit Control (VLC) indicators illuminate to
indicate that VLC is active. With the VLC upper limit
activated, the VLC Upper indicator is illuminated. If the
VLC lower limit is activated, the VLC Lower indicator is
illuminated.
If VLC is active, and Vld is within 1 volt of the VLC limit,
the appropriate VLC and Band Indicator will both be
illuminated.
Voltage Reduction Control Active Indicator LED
This indicator is illuminated whenever Voltage Reduction
Control is in effect. The VRC LED indicator flashes a
unique pattern to indicate which stage, step, or set is active.
The pattern depends upon the VRC Mode as described in
Table 2.3. See Section 4.4.3 for more information.
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