4 Setting Up the MJ-5 Control Panel
Siemens Industry, Inc.
22
voltage to 115, 120, or 125 Volts. See U2 PT and P2 PT
data items above. Also see Section 5.3.2.
4.3.13 NeutOvRun (Neutral Overrun)
The Neutral Overrun data item keeps the tap motor on for a
specified amount of time when making a tap change into
the neutral tap position. This ensures that the reversing
switch is always closed in order to prevent the contacts
from corroding due to capacitive discharge. For regulators
with a TLG mechanism set to 2.0 seconds. For regulators
with a TLF mechanism set to 1.7 seconds.
4.3.14 Min/Max Reset
The Min/Max Reset data item resets Meter and Demand
max/min values in the microprocessor to current
instantaneous values. This function is useful when setting
up the microprocessor for the first time, or when you want
to reset electronically-maintained values.
Note:
Do not use this function unless you want to reset all
Meter and Demand min/max values; to reset selected
values, use the Cancel/Reset key described in Chapter 2.
To request that Meter and Demand Max/Min values be
reset, view Reset Max/Min; use the Change/Save Key and
the Scroll keys to change the default N(o) to Y(es). Then
press the Change/Save key to complete the change process.
4.3.15 Version
Main Processor software version NN.NNNN. This data
item displays the installed version of the microprocessor
control program.
4.3.16 Memo 1 and Memo 2
These two data items allow you to record installation-
specific information that can be viewed at a later time. For
example, you might wish to use one Memo to document the
regulator’s serial number, and the other Memo to document
its location. This information could then be viewed by a
remote operator via a communications link.
To enter data into these data items, view the <
CONFIG-
URE
> menu; then use the Scroll keys to view Memo 1 or
Memo 2. The display screen responds by flashing the
“blank” character (■) in the leftmost position of the ten
character Memo field. This indicates the character to be
changed. Use the ▲ and ▼ keys to step through the alpha
and numeric characters until the desired character is
presented on the display screen. Then press the ► key to
move the cursor to the next character to the right, and so on
until all ten characters of the Memo have been entered.
When you have completed entering the Memo, press the
Change/Save key to complete the change.
Valid characters are A-Z; 0-9; space; comma; semi-colon;
period; dash; slash; ampersand (&), and the # character.
Default is for Memo 1 to contain the regulators serial
number and for Memo 2 to contain the initials of the
control panel tester.
The <ADV CONFIGURE> Menu
4.3.17 Meter Volts (Meter Scaling)
The Meter Volts data item determines which voltage is
presented on the display screen. You can choose either the
Primary side (system voltage—e.g., 7620 V) or the
Secondary side (120 V nominal).
Specify PRI if you wish to monitor the system-level
voltage; specify SEC if you wish to monitor voltage scaled
to the nominal 120 volt range. Voltages in the <METER>
menu are displayed according to the Meter Volts setting.
Note:
Power and energy calculations are always derived
from the system-level voltage and are not affected by the
Meter Volts setting.
4.3.18 I Threshold% (Low Current Threshold)
The I Threshold% data item defines a threshold for load
current magnitude, below which automatic mode tap
changes are inhibited. This threshold is defined as a
percentage of the CT primary rating (see CTratio above).
For example, in the case of a regulator with a CTratio of
200:0.2, the CT primary rating would be 200 A. If you
specify I Threshold% = 4, you are defining a low current
threshold of 8 A. (4%*200 A = 8 A). To set the low current
threshold, view I Threshold%: and specify a percentage of
the full scale CT primary rating.
4.3.19 I Shift (Current Shift)
The I Shift data item compensates for system current-to-
voltage phase differences. Consult the factory for proper
application of this data item. (Note: This data item is
primarily intended for use with Load Tap Change (LTC)
transformers.)
4.3.20 I Load Max (Maximum Load Current)
This item specifies the Maximum Load Current as a
percentage of the Full Load Current. When the load current
(Ild) exceeds the Maximum Load Current, the MJ-5
activates the Overcurrent Alert condition.
4.3.21 PT Threshold (Potential Transformer
Threshold)
The PT Threshold data item defines a low-voltage
threshold. This parameter allows you to specify a voltage
level below which automatic mode tap changes will be
inhibited.
4.3.22 Time and Date Items
Time (Time of Day)
The Time data item allows you to set the real-time clock.
Specify the present time, TIME: HH:MM:SS A/P (e.g.
04:34:54P).
