Siemens MJ-5, Инструкция по установке и эксплуатации

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4 Setting Up the MJ-5 Control Panel
Siemens Industry, Inc. 26
4.4.1 Regulator set points
Regulator set points define the operating limits for
Automatic mode operation. Two sets of limits are
maintained: one for forward power flow conditions and
another for reverse power flow conditions.
Voltage Level set point
The Voltage Level set point defines the nominal level you
wish the regulator to maintain.
Bandwidth set point
The Bandwidth set point defines the voltage range within
which the regulator output is maintained. It is divided
equally above and below the Voltage Level set point.
For example, a Bandwidth of 6 volts with a Voltage Level
set point of 120.0 volts specifies that any load voltage
between 117 volts and 123 volts is “in band.”
Figure 4.5: Flow Chart of VRC Modes
4.4.3 Voltage Reduction Control Items
Voltage Reduction Control (VRC) is used to reduce output
voltage. When activated, VRC has the effect of lowering
the Voltage Level set point. Voltage reduction is
accomplished in one or more discrete steps which are
defined as a percentage of the voltage level set point (Fwd
Volts, Rev Volts). VRC operates immediately to reduce
output volt-age without waiting for completion of the Time
Delay.
The following sections describe each of the VRC menu
items, and explain how to set them.
ALT Delay
When the VRC2 In item is set for ALT DELAY, an
alternate time delay is used before commanding a tap
change when the VRC2 contacts are closed. When the
VRC2 contacts are open, the standard (Fwd Delay) time
delay is used.
VRC Status
The VRC Status data item displays present VRC
information in the display panel. It can be directly accessed
with the VRC fast-path key, or viewed from the
<
REGULATOR > menu.
Time Delay set point
The Time Delay set point defines the amount of time the
controller will wait before commanding a tap change.
4.4.2 Line Drop Compensation
The Line Drop Compensation (LDC) data item defines the
assumed voltage drop between the regulator and the load
center. Settings are expressed in volts.
To specify LDC values, view Fwd Comp (R) for the
Forward Resistive component and Fwd Comp (X) for the
Forward Reactive component. In systems with reverse
power flow, view Rev Comp (R) and Rev Comp (X) to
specify the Reverse components. A Line Drop Calculator
software application is available on the Siemens website.
This application automatically calculates the LDC values
when the system parameters are entered.
Information displayed includes: percent reduction presently
in effect (nn.n%), the VRC mode (L - Local, A -Automatic,
R - Remote) and the present step/stage (0-3). For example,
if VRC is presently at 5%, Remote, and MJ-X mode Stage
3, the display panel would show VRC Stat=05.0%R3.
VRC1 In
This item defines which feature is implemented when the
external terminal block contacts (VRC1) are closed. Select
VRC to enable remote Voltage Reduction Control. Choose
X-COMP to enable reactive compensation polarity control.
When VRC1 contacts are closed, the LDC polarity is
reversed.
VRC2 In
This item defines which feature is implemented when the
VRC2 contacts are closed. Choose VRC to enable remote
Voltage Reduction Control. Choose ALTDELAY to use the
ALT Delay feature described above. Choose LO XBATT to
use these terminals for monitoring status change (close to
open or vice versa). Choose AUTO INH to inhibit the
processor from making automatic tap changes.