Appendix D: Menu Parameters
Siemens Power Transmission & Distribution, Inc.
57
D Menu Parameters
D.1
<CONFIGURE> Menu:
Leading and Lagging Regulators
The following steps will help you determine which of the
two regulators in a Delta configuration is “leading” and
which is “lagging” on an open Delta installation:
1.
Disable automatic control of tap changer. Set Raise/
Lower tap switch to OFF. Set Remote/Auto/Manual
switch on both controllers to Manual.
2.
Use the Configuration Keys to temporarily set both
controllers to System type = WYE. This will be cor-
rected in step 7.
3.
Assure that there is load current on the line. Load cur-
rent must be of sufficient magnitude to cause a defi-
nite response of the line drop compensation circuit.
Normally, 25% of the regulator setting will be ade-
quate.
4.
Adjust both front panel controls to the same settings:
Bandwidth
2.0 V
Voltage Level
120 V
Time Delay
0 Seconds
Resistance Volts
0 V
Reactance Volts
(+) 12
5.
Set the Remote/Auto/Manual switch to AUTO on both
controllers.
6.
Allow both regulators to run and come to rest in band.
The regulator whose tap position is closest to maxi-
mum is the “lagging” regulator. The other regulator is
the “leading” regulator.
Note:
The amount of tapchange excursion can be
made more or less, if desired, by appropriate
adjustment of the reactance volts setting.
7.
Use the Configuration keys to set the System type to
Delta Lead for the leading regulator and to Delta Lag
for the lagging regulator, as determined in step 6.
D.2
<REGULATOR> Menu:
Line Drop Compensation
There are several methods used to determine line drop
compensation settings, The “Load Center” method is
probably the most commonly used and most clearly illus-
trates the procedure.
1.
Using knowledge of the distribution feeder and the
tables below, establish the conductor resistance and
reactance per mile of feeder.
EXAMPLE: Conductor 4/0 ACSR, Regular Flat Spacing at
24 inches.
R=0.592 ohms/mile X=0.692 ohms/mile
2.
Determine compensation multiplier, k, as
•
Single phase
•
Wye Connected
•
Delta Connected
EXAMPLE: The regulators involved are 3 - 333 kVA at 7.2
kV configured in a wye-connected three phase bank. (The
CT primary for this regulator is 400 A.)
Note:
Multipliers for many common system voltages
and regulator ratings are included in tables D.4
and D.5 below.
3.
Determine the Line Drop Compensation Settings
Resistive Compensation Setting = k x line length (mi) x
resistance (ohms/mi)
Reactive Compensation Setting = k x line length (mi) x
reactance (ohms/mi)
EXAMPLE: The line is 3 miles long.
Resistance Setting = 6.67 x 3 x 0.592 = 12V
Reactance Setting = 6.67 x 3 x 0.692 = 14V
D
24 x 24 x 48
3
30 inches
=
=
k = 2.0x
Current Tr ansformer Rating
Voltage Tr ansformer Ratio
k = 1.0x
Current Tr ansformer Rating
Voltage Tr ansformer Ratio
k = 1.73x
Current Transformer Rating
Voltage Transformer Ratio
k = 1.0
400
7200 / 120
= 6.67
Summary of Contents for MJ-XL
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