Siemens MJ-4A Installation And Operation Manual page 30

4
Setting Up the MJ-4A & MJ-4B Control Panel
for the last 10 minutes, the regulator will not step past 8
raise or lower and it will move to 8 raise or lower if it is on
a higher tap.
When planning to overload a regulator use either the Soft
Variamp or the knobs on the position indicator. Auto Vari-
amp is for protection in case of accidental overload only.
The Variamp limits are defined in the voltage regulator
instruction manual.
4.3.29 Soft Variamp (Software Variamp)
The Soft Variamp data item is a software implementation
of Vari-Amp knobs on the position indicator. If set ON,
then R Limit % and L Limit % will prohibit tap raise/lower
past that position. The regulator will be limited by both
the Vari-Amp knobs and the Soft Variamp. The actual
boundary will be the most restrictive combination of the
two (e.g., knobs limit R to 10%, L to 7 .5% and software
limit R to 5% and L to 8.75%. In this case the limits
would be R at 5% and L at 7 .5%).
4.3.30 R Limit, L Limit
These items set the Tap Position Raise and Lower Limit
values; the control uses the limit values to check for
"raise/lower limit reached" Alert conditions. Configure
these parameters to match the Vari-Amp settings on the
side of the Tap Position Indicator Dial mounted on the reg-
ulator. (For most applications, the Vari-Amp settings are at
10%.) If the Tap Position reaches or exceeds the R Limit
Setting, the control activates the "R Limit Reached" Alert.
Likewise, if the Tap Position reaches or exceeds the L
Limit Setting, the control activates the "L Limit Reached"
Alert.
The R Limit/L Limit settings are always used for alerting—
these limit settings only prevent tap raise/lower operations
from exceeding the limits if Soft Variamp setting is turned
ON.
4.3.31 Slave-Master
The Slave-Master data item defines how to place controls
in locked-step with each other. Whenever the Master
makes a tap change it tells the slave to make a matching
tap change and waits for it to do so. Contact your Siemens
representative for information about this custom applica-
tion.
4.3.32 Tap Alert
The Tap Alert data item enables or disables all tap alerts,
including: R Limit Reached, L Limit Reached, Neut Sig Err,
Tap Pos ???, and Tap Track Err.
4.3.33 Alrt M=? C=? S=?
The Alrt data item permits groups of alerts to be turned off
and on. Metering (M) alerts include Low Current, Low PT
Thresh, Over Current, and High Voltage. Control (C) alerts
include Auto Inhibit, Pseudo Manual, and Not in Auto. Sys-
tem (S) alerts include NV RAM Reset, Low Battery, and
Self Test Fault. Press change and use the left/right and up/
down arrows to adjust the M, C, and S alert settings.
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4.3.34 Tap Resync
The Tap Resync data item determines whether the elec-
tronic tap position will resynchronize itself to neutral when
the tap changer is on the neutral tap. Turning this data
item OFF results in better tap tracking and the control will
not adjust its tap position according to the neutral signal.
Turning this data item ON will require the neutral signal
status to precisely match the electronically tracked tap
position and the timing of the operations counter or the
maintained tap position will be purposely discarded.
4.3.35 CommAutoInh (Communications Auto
Inhibit)
The Comm Auto Inhibit data item provides a way to
change the state of the Auto Inhibit status at the control
panel. This can be used if the Auto Inhibit state is turned
on remotely and the communications link goes down; in
this event, someone can go to the controls location and
enable automatic operation again.
4.3.36 DspScr (Default Display Screen)
If the Screen Timeout period expires as defined by Screen
t.o., the display will change to show the default display
screen set by this data item. The following display screens
are available: <METER> (default), TapContr (switch posi-
tion), Vld (load bushing voltage), Vcomp (compensated
voltage at load center), Ild (load current), and Total Ops.
The first keypress made after a control has timed out will
change the screen back to <METER>.
4.3.37 Lower LED
In the MJ-4A and MJ-4B panels, the Raise and Lower
LEDs have been combined to one single LED. When low-
ering the Tap position the user may chose to have the LED
glow solid or blink by chosing the setting. The Raising of
the tap position will be indicated by the LED glowing
solid,The default setting for the Lower LED is solid.
4.3.38 P2 Calc
P2 Calculation can be enabled or disabled from the P2
Calc screen. P2 Calculation should be enabled for regula-
tors that have no PT. For regulators with voltages on both
the Load and Source bushing, the P2 calculation may be
disabled, so that when the sensing fuse is blown that volt-
age in the meter menu will be indicated by dashes.The
defualt is for P2 Calculation to be enabled.
4.3.39 U2/P2 Out
When measured with a multi-meter, the Load Volt-
age(unscaled) terminals on the front panel have been
locked to show the Load side voltage by default. The load
voltage will vary depending on the user defined power
flow mode and the power flow direction. The terminals
may be locked to show exclusively U2 or P2 only, or the
terminals can be configured to toggle between the two
voltages with successive key presses of the U2 P2 Key.
Siemens Energy, Inc.