87twflt
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Instructions
Disclaimer
This spreadsheet presents information about Basler Electric relays. It has been
prepared as a convenience to our customers, and there is no expressed or
implied commitment to maintain or update this file. In developing this
software, Basler has attempted to offer the most accurate information possible.Basler does not warrant that the software is free from bugs, errors or other
program limitations. Users are encouraged to consult with a Basler Electric
representative to determine the accuracy of the data and results for the specific
use or purpose of the user.
The spreadsheet is not password protected, to enable the user to modify it
or to customize if for the users own purposes.
By use of this program, the user agrees that Basler disclaims all warranties of
noninfringement of third party rights, quality, performance, merchantability, or
fitness for a particular purpose. The user assumes the entire risk as to the
quality and performance of the software. In no event will Basler be liable for
any indirect, special or consequential damages.
In the event of any litigation regarding this software, the user agrees that venue
shall be in the State of Illinois.
Purpose of this Spreadsheet Template
This spreadsheet template has been created to assist users of the Basler
Electric 87T Transformer Differential Relay to perform the settings calculations
contained in Section 4, Installation, of the Instruction Manual. The calculations
are based upon Procedure 2.
The spreadsheet is also useful as a learning tool for obtaining greaterunderstanding of the application of transformer differential protection. The user
can selectively try different combinations of parameters to see how each
parameter affects the others in coming up with the settings for the relay.
There are two versions of this template. The first version, 87twoflt.xls, has fields
for you to enter the fault currents that you calculate from your own fault study.
This version of the relay can be used for Delta/Wye, Delta/Delta, or Wye/Wye
transformers. The second version, 87twflt.xls, has fields for entering appropriate
BE1-87T Settings Record With Fault Calculations - Rev. A
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Instructions
system and transformer impedance data and will calculate the fault currents for
you. This version is limited to Delta/Wye transformers and requires that you
have the Analysis Toolpak Add-In installed in Excel. The fault calculations are
located on a hidden sheet named "scratch".
Please feel free to modify these spreadsheets as necessary to optimize them
for your own use.
How to use this Tool
Instructions for creating settings files for your BE1-87T relay using the Excel
Template file:
1. Start Excel and create a new file based upon this file by clicking
File/Save As on the menu after selecting 87Twoflt or 87Twflt.
2. On the DATA tab, fill in the data fields for the transformer that you are
calculating settings for.
3. Once you have filled out the data sheet, click over to the calculated values
tab and fill in the desired settings in the cells highlighted in yellow.
4. Look for warning messages that indicate problems with the parameters that
were entered. If necessary, click back over to the Data tab and adjust
parameters as necessary to make corrections.
Revision Notes:
Rev. A. Removed the CT internal resistance from the CT performance
calculations. The technique used in this spreadsheet for calculating the CT
performance uses the ANSI accuracy class. Since the accuracy class rating is
based upon the CT's terminal voltage, the CT's internal resistance should not
be included in the saturation factor calculation. This technique tends to be
conservative. for greater accuracy, it is recommended that the user determine
CT performance by examining the excitation curves.
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Instructions
Basler Electric Company, 12570 State Route 143, Highland, Illinois 62249-1074 USA
Phone: 618/654-2341 - Fax: 618/654-2351 - Website: www.basler.com
5/16/2009 Converted from template files to XLS files.
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DATA
87T SETTINGS BASED ON PROCEDURE TWO
With Fault CalculationsThis version of the 87T settings calculation workbook template uses fault current magnitudes calculated
based upon the system impedance data entered on the data sheet for CT performance calculations.
You need the Analysis Toolpak Add-In installed in Excel to use this version of the template.
Fields highlighted in yellow are for data entry.
SPECIFICATIONS VALUE D SIDE Y SIDE
SYSTEMKVLL (BASE) 69 12.47
BASE MVA 12
SYSTEM Z1H (% @ BASE MVA) 0.879
SYSTEM Z0H (% @ BASE MVA) 1.05
SYSTEM Z1L (% @ BASE MVA) 999
SYSTEM Z0L (% @ BASE MVA) 999
TRANSFORMER
MVA (self cooled - OA) 12
MVA (forced cooled - FA) 20
MVA (expected max load) 20
XFMR IMPEDANCE (% @ OA MVA) 4.361
LTC range +/- % 10
GROUNDING RESISTANCE (OHMS) 0
CTsPRI CURRENT RATING (FULL WINDING) 600 1200
PRI CURRENT RATING (TAPPED) 300 800
SEC CURRENT RATING 5 5
CT ACCURACY CLASS (volts @ 20X In) 400 800
CT CONNECTION (D or Y) y yONE WAY LEAD RESISTANCE (Ohms) 0.7 0.7
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CALC. VALUES
Fields highlighted in yellow are for entry of settings.
Fields highlighted in white are carried over from the data sheet.
Fields highlighted in blue are calculated values.
SPECIFICATIONS D SIDE Y SIDE WARNINGSTRANSFORMER (from DATA SHEET)
LL 69.00 12.47
MVA Maximum Load 20.00
Current @ Expected Max Load 167 926
SYSTEM PER UNITase curren , LL ase 100 556
FAULT CURRENTS
3PH, wye side fault, EXTERNAL (F1) 1916 10603
3PH, delta side fault, EXTERNAL (F2) 0 0
PH-G, wye side fault, EXTERNAL (F1) 1172 11231
PH-G, delta side fault, EXTERNAL (F2) 0 0
CT PERFORMANCE
CT Connection y y
CT Ratio (Turns) 60 160
CT accuracy class 400 800
CT effective class (x Full CTR/Tapped CTR) 200 533
Secondary Current in CT (Max Load) 2.79 5.79 CT exceeds nominal secondary rating
One way leads resistance (ohms) 0.7 0.7
CT voltage for 3ph fault, wye side, external (F1) 22.36 46.39
CT voltage for 3ph fault, delta side, external (F2) 0.00 0.00
CT voltage for ph-g fault, wye side, external (F1) 13.67 98.27
CT voltage for ph-g fault, delta side, external (F2) 0.00 0.00
Max.CT voltage (external faults) 22.36 98.27
Saturation Factor for external faults 0.11 0.18
RELAY SETTINGS 0 0
Relay input circuit number 1 2
Tap Setting Calculations
CT connection current conversion factor 1.00 1.00
Current in Relay (Max Load) 2.79 5.79
Phase compensation jumper selection y d
Relay current conversion factor 1.00 1.73
Effective relay current (Max Load) 2.79 10.02Check tap adjust spread (must be