Vanguard EZCT-2000A User Manual
TM
EZCT-2000A
DIGITAL CURRENT-TRANSFORMER TESTER
USER’S MANUAL
Vanguard Instruments Company, Inc.
1520 S. Hellman Ave.
Ontario, California 91761, USA
TEL: (909) 923-9390
FAX: (909) 923-9391
March 2014
Revision 1
EZCT-2000A USER’S MANUAL REV 1
SAFETY SUMMARY
FOLLOW EXACT OPERATING PROCEDURES
Any deviation from the procedures described in this User’s Manual may create one or more
safety hazards, may damage the EZCT-2000A, or cause errors in the test results. Vanguard
Instruments Company, Inc. assumes no liability for unsafe or improper use of the EZCT-2000A.
All safety precautions provided in this manual must be observed during all phases of testing
including test preparation, test lead connection, actual testing, and test lead disconnection.
SAFETY WARNINGS AND CAUTIONS
The EZCT-2000A can produce a voltage up to 2,000 Vac that can cause severe injury and/or
equipment damage. Due to this reason, the EZCT-2000A shall be used only by trained
operators.
The EZCT-2000A’s X output terminals are rated to 2,000 Vac working voltage. Any voltage above
2,000 Vac will damage the input circuitry. Please see section 3.2 for further information.
All devices under test shall be off-line and fully isolated. Never attempt to test any current
transformer still connected to a circuit. All current transformer terminals shall be isolated
before conducting any test with the EZCT-2000A.
Always ground the EZCT-2000A to a substation ground before connecting the test cables to a
transformer.
DO NOT MODIFY TEST EQUIPMENT
To avoid the risk of introducing additional or unknown hazards, do not install substitute parts or
perform any unauthorized modification to any EZCT-2000A test unit. To ensure that all
designed safety features are maintained, it is highly recommended that repairs be performed
only by Vanguard Instruments Company factory personnel or by an authorized repair service
provider. Unauthorized modifications can cause safety hazards and will void the manufacturer’s
warranty.
WARNING
Do not remove test leads during a test. Failure to heed this warning can result in electrical
shock to personnel and damage to the equipment.
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REV 1 EZCT-2000A USER’S MANUAL
TABLE OF CONTENTS
CONVENTIONS USED IN THIS DOCUMENT ....................................................................... 1
1.0 INTRODUCTION .................................................................................................................. .. 2
1.1 General Description and Features ................................................................................... 2
1.2 Furnished Accessories ...................................................................................................... 4
1.3 Technical Specifications ................................................................................................... 5
1.4 EZCT-2000A Controls and Indicators ............................................................................... 6
2.0 PRE-TEST SETUP ................................................................................................................... 8
2.1 Operating Voltages .......................................................................................................... 8
2.2 LCD Screen Contrast Control ............................................................................................ 8
2.3 Printer Paper Control ....................................................................................................... 8
2.4 Printer Paper .................................................................................................................... 8
3.0 OPERATING PROCEDURES ................................................................................................. 10
3.1 EZCT-2000A Cable Connections ..................................................................................... 10
3.2 EZCT-2000A X Input Voltage Warning ........................................................................... 12
3.3 Performing Tests ............................................................................................................ 13
3.3.1. Entering Test Record Header Information ............................................................. 13
3.3.2. Performing Resistance, Excitation, and Ratio Tests ............................................... 16
3.4 Working With Test Records ........................................................................................... 27
3.4.1. Restoring and Printing a Test Record From Flash EEPROM ................................... 27
3.4.2. Restoring and Printing a Test Record From a USB Flash Drive .............................. 31
3.4.3. Printing a Restored Test Record ............................................................................. 34
3.4.4. Printing a Directory of Test Records Stored in the EZCT-2000A’s Memory ........... 36
3.4.5. Printing a Directory of Test Records Stored in a USB Flash Drive .......................... 39
3.4.6. Copying Test Records to a USB Flash Drive ............................................................ 41
3.4.7. Erasing Test Records From the Flash EEPROM ...................................................... 44
3.4.8. Erasing Test Records From a USB Flash Drive ........................................................ 47
3.5 Working With Test Plans ................................................................................................ 50
3.5.1. Extracting the Test Plan From a Test Record ......................................................... 50
3.5.2. Printing a Directory of Test Plans Stored in the EZCT-2000A’s Memory ............... 52
3.5.3. Printing a Directory of Test Plans Stored in a USB Flash Drive. ............................. 54
3.5.4. Printing a Test Plan ................................................................................................. 56
3.5.5. Erasing Test Plans From the Flash EEPROM ........................................................... 58
3.5.6. Erasing Test Plans From a USB Flash Drive ............................................................. 61
3.5.7. Loading a Test Plan from the EZCT-2000A’s Flash EEPROM .................................. 64
3.5.8. Loading a Test Plan from a USB Flash Drive ........................................................... 66
3.5.9. Running a Test Using a Loaded Test Plan ............................................................... 68
3.5.10. Unloading a Test Plan from the Working Memory ................................................ 73
4.0 CHANGING SETUP PARAMETERS ....................................................................................... 74
4.1 Setting the Knee Point Marker ...................................................................................... 74
4.2 Enabling and Disabling the Buried CT in Transformer Delta Option ............................. 76
4.2.1. Enabling the Buried CT in Transformer Delta Option............................................. 76
4.2.2. Disabling the Buried CT in Transformer Delta Option ............................................ 77
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4.3 Setting the Clock ............................................................................................................ 81
5.0 DIAGNOSTICS, VERIFICATION, AND TROUBLESHOOTING ................................................. 83
5.1 Performing a Diagnostics Test ....................................................................................... 83
5.2 Verifying the EZCT-2000A’s Vx Sense Circuit Using an External Meter ......................... 85
5.3 Verifying the EZCT-2000A’s Ix Sense Circuit Using an External Meter ........................... 86
5.4 Quickly Verifying the EZCT-2000A’s Turns Ratio Circuit ................................................ 87
5.5 Troubleshooting Guide .................................................................................................. 88
7.0 Appendix A - Calculating Turns Ratio on a Shunt Reactor ................................................. 92
LIST OF TABLES
Table 1. EZCT-2000A Technical Specifications ................................................................................ 5
Table 2. Functional Descriptions of EZCT-2000A Controls and Indicators ..................................... 7
Table 3. Descriptions of Tabulated Test Results Elements ........................................................... 25
Table 4. Description of Test Plan Elements .................................................................................. 57
LIST OF FIGURES
Figure 1. EZCT-2000A Controls and Indicators ............................................................................... 6
Figure 2. Typical EZCT-2000A Excitation and Ratio Test Cable Connection ................................. 10
Figure 3. Bushing CT Connection on Delta Transformer .............................................................. 11
Figure 4. Bushing CT Connection on Y Transformer ..................................................................... 11
Figure 5. Sample CT Name Plate ................................................................................................... 12
Figure 6. Typical EZCT-2000A Tabulated Report Printout ............................................................ 24
Figure 7. Typical EZCT-2000A Graphic Report .............................................................................. 26
Figure 8. Typical EZCT-2000A Graphic Report with Multiple Plot Curves .................................... 26
Figure 9. Typical Internal Test Record Directory Printout ............................................................ 38
Figure 10. Typical USB Flash Drive Record Directory Printout ..................................................... 40
Figure 11. Typical EZCT-2000A Flash EEPROM Test Plan Directory Printout ............................... 53
Figure 12. Typical USB Flash Drive Test Plan Directory Printout .................................................. 55
Figure 13. Typical Test Plan Printout ............................................................................................ 57
Figure 14. Graphic Report Showing Knee Point Marker ............................................................... 75
Figure 15. Buried CT in a Delta Transformer Illustration 1 ........................................................... 79
Figure 16. Buried CT in a Delta Transformer Illustration 2 ........................................................... 79
Figure 17. EZCT-2000A Vx Verification Test Connections ............................................................. 85
Figure 18. EZCT-2000A Ix Verification Test Connections .............................................................. 86
Figure 19. EZCT-2000A Turns Ratio Verification Test Connections .............................................. 87
Figure 20 ....................................................................................................................................... 92
Figure 21 ....................................................................................................................................... 93
Figure 22 ....................................................................................................................................... 94
Figure 23 ....................................................................................................................................... 95
Figure 24 ....................................................................................................................................... 96
Figure 25 ....................................................................................................................................... 97
Figure 26 ....................................................................................................................................... 98
Figure 27 ....................................................................................................................................... 98
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CONVENTIONS USED IN THIS DOCUMENT
This document uses the following conventions:
•
A key or switch on the EZCT-2000A is indicated as
[KEY]
and
[SWITCH].
Menu options are referenced as (MENU OPTION).
•
Screen and menu names are referenced as “SCREEN/MENU NAME”.
•
The terms “test record” and “test shot” are used interchangeably.
•
• EZCT-2000A LCD screen output is shown as:
1. OPTION 1
2. OPTION 2
3. OPTION 3
4. OPTION 4
5. OPTION 5
• When instructions are provided, the menu item that should be selected is shown in bold as
shown below (option 3 should be selected):
1. OPTION 1
2. OPTION 2
3. OPTION 3
4. OPTION 4
5. OPTION 5
• Warning messages are indicated as:
Warning message
WARNING
• Important notes are indicated as:
Note details
NOTE
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EZCT-2000A USER’S MANUAL REV 1
1.0 INTRODUCTION
1.1 General Description and Features
The EZCT-2000A is Vanguard’s third-generation microprocessor-based current transformer test
set. The EZCT-2000A can perform the current transformer (CT) excitation test, measure the CT
winding resistance and CT current-ratio automatically. All of the EZCT-2000A’s test leads can be
connected to the CT output terminals (X1, X2, X3, X4 and X5), eliminating the need for lead
switching during testing. Test voltage output is automatically raised and lowered by the EZCT2000A without any operator intervention. With up to 2000 Vac excitation test voltage available,
the EZCT-2000A can easily perform excitation tests on very large CT’s.
Excitation Test
The CT excitation test is performed using the ANSI/IEEE C57.13.1, IEC 60044-1 test method. The
test voltage range for the CT excitation test (50 Vac, 300 Vac, 500 Vac, 1200 Vac or 2000 Vac)
can be selected, and then the test voltage is raised and lowered automatically by the EZCT2000A. The excitation test voltage and current data is collected and stored in the unit’s internal
memory. Any of the 10 possible combinations of X1 to X5 can be tested since all of the unit’s
test leads can be connected to all of the CT output terminals at the same time. Up to 10
excitation tests can be stored in one record. Once the test is completed, test results can be
printed and excitation curves can be plotted on the built-in 4.5-inch wide thermal printer.
CT Ratio and Polarity Test
The EZCT-2000A determines the CT current-ratio using the ANSI/IEEE C57.12.90 measurement
method. A test voltage is applied on any two terminals of the CT (X1 to X5), and the induced
voltage is measured through the CT’s H1 and H2 terminals. The CT current-ratio is displayed on
the screen and stored in memory. The current-ratio measuring range is from 0.8 to 5,000 to 1.
The CT winding polarity is displayed as a “+” sign (in-phase) or a “-” sign (out-of-phase) and is
annotated with the phase angle in degrees.
CT Winding Resistance Test
The EZCT-2000A can also measure the DC resistance of the CT winding under test. The DC
winding resistance measuring range is from 100 micro-ohms to 10 ohms.
User Interface and Display
The EZCT-2000A features a back-lit LCD screen (240 x 128 dot graphic) that is viewable in both
bright sunlight and low-light levels. A rugged, alpha-numeric, membrane keypad is used to
control the unit.
Built-in Thermal Printer
A built-in 4.5-inch wide thermal printer can print the current transformer test report and plot
the excitation curves.
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Test Record Header Information
Test record header information can include the company name, substation name, circuit ID,
manufacturer, CT serial number, operator’s name and test record comments. In addition to the
test record header, a 20-character test description for each test in the record (10 tests per
record) can also be entered.
Internal Test Record Storage Capacity
The EZCT-2000A can store up to 140 test records in Flash EEPROM. Each test record may
contain up to 10 excitation curves, current-ratio readings, polarity and DC resistance readings.
Test records can be recalled and printed on the built-in thermal printer.
Internal Test Plan Storage Capacity
The EZCT-2000A can store up to 128 CT test plans in Flash EEPROM. A test plan defines the
excitation test voltage and current range selection, CT nameplate ratio, and CT winding
terminals (X1 to X5) for each of the tests. Up to 10 test definitions can be stored per test plan.
The use of a test plan greatly simplifies the CT testing process; the EZCT-2000A is connected to
the CT terminals and a test plan is simply selected and run. Test plans can be created on the
EZCT-2000A itself or created on a PC and downloaded to the EZCT-2000A via the unit’s built-in
RS-232C or USB interfaces.
External Data Storage
The EZCT-2000A features a standard USB Flash drive interface that makes it very convenient to
store and transfer test records and test plans. By plugging in a USB Flash drive, you can quickly
transfer your test records and test plans between a computer and the EZCT-2000A without the
need to connect the unit to the computer.
Computer Interface
The EZCT-2000A can be used as a stand-alone unit or can be computer-controlled via the builtin RS-232C or USB interfaces. A Windows® XP/Vista-based Current Transformer Analysis
software application is provided with each EZCT-2000A. This software can be used to retrieve
test records from the EZCT-2000A, create test plans, download test plans to the EZCT-2000A,
and can also be used to run CT tests from the PC. Tabulated test records can be exported in
Microsoft® Excel format.
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1.2 Furnished Accessories
The EZCT-2000A comes furnished with the following:
• 1 Power Cord
• 1 20-foot X Cable Set
• 1 35-foot H Cable
• One RS-232C serial cable
• One USB cable
• Ground Cables
• Duffel bag
• Transportation Case
EZCT-2000A USER’S MANUAL REV 1
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®
1.3 Technical Specifications
Table 1. EZCT-2000A Technical Specifications
TYPE Portable current-transformer test set
PHYSICAL SPECIFICATIONS 16.8”W x 12.6”H x 14”D (42.7 cm x 32.0 cm x 35.6 cm); Weight: 60 lbs
(27.2 Kg)
INPUT POWER 100 – 120 Vac or 200 – 240 Vac (factory pre-set), 50/60 Hz
MEASUREMENT METHOD ANSI/IEEE C57.12.90, IEC 60044-1 and ANSI/IEEE C57.13.1 standards
TEST OUTPUT VOLTAGES 0 – 50 Vac @ 10A max, 0 – 300 Vac @ 10A max, 0 – 500 Vac @ 5A max
0 – 1200 Vac @ 2A max, 0 – 2000 Vac @ 1.2 A max
VOLTAGE READING RANGE 0 – 2,200 Vac; Accuracy: ±1.0% of reading, ±1 volt
CURRENT READING RANGE 0 – 10A; Accuracy: ±1.0% of reading, ±0.02A
CURRENT-RATIO RANGE 0.8 – 999: 0.1%, 1000 – 1999: 0.3%, 2000 – 5000: 1%
PHASE ANGLE
MEASUREMENT
RESISTANCE READING
RANGE
DISPLAY Back-lit LCD Screen (240 x 128 dot graphic; 114mm x 64mm); viewable in
PRINTER Built-in 4.5-inch wide thermal printer
COMPUTER INTERFACES One RS-232C port (115k baud), One USB port
PC SOFTWARE Windows
EXTERNAL DATA STORAGE One USB Flash drive interface port (Flash drive not included)
INTERNAL TEST RECORD
STORAGE
INTERNAL TEST PLAN
STORAGE
SAFETY Designed to meet UL 61010A-1 and CAN/CSA C22.2 No. 1010.1-92
ENVIRONMENT Operating: -10˚ to 50˚ C (15˚F to +122˚ F); Storage: -30˚ C to 70˚ C (-22˚F
CABLES One 20-foot X cable set, One 35-foot H cable, power cord, One cable-
WARRANTY One year on parts and labor
0 – 360 degrees; Accuracy: ±1.0 degree
100 micro-ohms – 10 ohms; Accuracy: 2% of reading, ±1 count, ±10 μohms
bright sunlight and low-light levels
price
Stores 140 test records. Each test record may contain up to 10 sets of
excitation, resistance and ratio data
Stores 128 test plans. Each test plan can store 10 excitation test voltage
and current settings
standards
to +158˚ F)
carrying duffel bag
XP/Vista-based CT Analysis software is included with purchase
The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.
NOTE
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EZCT-2000A USER’S MANUAL REV 1
1.4 EZCT-2000A Controls and Indicators
The EZCT-2000A’s controls and indicators are shown in Figure 1 below. A leader line with an
index number points to each control and indicator, which is cross-referenced to a functional
description in Table 2. The table describes the function of each item on the control panel. The
purpose of the controls and indicators may seem obvious, but users should become familiar
with them before using the EZCT-2000A. Accidental misuse of the controls will usually cause no
serious harm. Users should also be familiar with the safety summary found on the front page of
this User’s Manual.
Figure 1. EZCT-2000A Controls and Indicators
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Table 2. Functional Descriptions of EZCT-2000A Controls and Indicators
Item
Number
1-5
6
7
8
9
10
11
12
13
14
15
16
17
Panel Markings Functional Description
Current transformer excitation voltage connectors. Each set of connectors
X1, X2, X3, X4, X5
H Current transformer primary input test cable connector.
GROUND Grounding stud.
AC receptacle.
Back-lit LCD Screen (240 x 128 dot graphic; 114mm x 64mm).
110-120 Vac,
12A, 50-60Hz
Rugged, alpha-numeric membrane keypad
HIGH VOLTAGE
PRESENT
EMERGENCY
TURN OFF
“PUSH”
Built-in 4.5-inch wide thermal printer.
USB USB PC interface.
USB MEM USB Flash drive interface port
RS-232C RS-232C PC interface. Baud rate is set for 115KB, 8 data bits, 2 stop bits.
contains a test voltage connector and sensing connector. The EZCT-2000A’s X
output terminals are rated to 2000 Vac working voltage. Any voltage above
2000 Vac will damage the input circuitry.
Power switch with built-in circuit breaker.
LED warning indicator that is illuminated when high voltage is present.
Emergency turn off switch.
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EZCT-2000A USER’S MANUAL REV 1
2.0 PRE-TEST SETUP
2.1 Operating Voltages
The EZCT-2000A’s operating voltage is preset at the factory for 100-120 Vac, 50/60 Hz or 200240 Vac, 50/60 Hz.
2.2 LCD Screen Contrast Control
To increase the LCD screen contrast, press and hold the [PAPER ∧ Contrast] key for two
seconds. Release the button when the desired contrast level has been reached.
To decrease the LCD screen contrast, press and hold the [PAPER ∨ Contrast] key for two
seconds. Release the button when the desired contrast level has been reached.
2.3 Printer Paper Control
To advance the thermal printer paper, press and release the [PAPER ∧ Contrast] key.
To retract the thermal printer paper, press and release the [PAPER ∨ Contrast] key.
2.4 Printer Paper
The EZCT-2000A’s built-in thermal printer uses 4.5-inch wide thermal paper for printing test
results. To maintain the highest print quality and to avoid paper jams, the use of thermal paper
supplied by Vanguard Instruments Company is highly recommended. Additional paper can be
ordered from the following sources:
Vanguard Instruments Co, Inc.
1520 S. Hellman Avenue
Ontario, CA 91761
Tel: 909-923-9390
Fax: 909-923-9391
Part Number: VIC TP-4 paper
BG Instrument Co.
13607 E. Trent Avenue
Spokane, WA 99216
Tel: 509-893-9881
Fax: 509-893-9803
Part Number: VIC TP-4 paper
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2.5 Replacing the Thermal Printer Paper
The roll of thermal paper is housed inside a dispenser underneath the printer cover. To replace
the paper, follow the steps below:
• Unscrew the two large printer cover screws and remove the printer cover.
• Remove the leftover thermal paper roll from the paper holder.
• Unroll the new thermal paper roll.
• Feed the thermal paper into the slot between the paper pocket and the rubber roller.
The printer will automatically pull the paper under the thermal head.
• Place the paper roll into the paper holder.
• Lift the thermal head and align the thermal paper if necessary.
• Re-install the printer cover.
Thermal paper has a chemical coating on one side of the paper. This side should be
facing the thermal print head. Incorrect paper loading may result in blank output on
NOTE
the thermal paper.
The thermal paper will show a red stripe to indicate that the roll is about to run out
of paper.
2.6 Computer Interface Ports
The EZCT-2000A features one USB and one RS-232C PC interface port. A Windows-based
“Current Transformer Analysis” software application is supplied with the EZCT-2000A. For
further information, please see the EZCT-2000 Software User’s Manual.
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EZCT-2000A USER’S MANUAL REV 1
3.0 OPERATING PROCEDURES
3.1 EZCT-2000A Cable Connections
Always connect the EZCT-2000A to the substation ground before connecting any test cables.
The EZCT-2000A is supplied with one 20-foot X cable set and one 35-foot H cable. The X cable
connections are required to run the current transformer excitation test. The H and X cable
connections are required to run the transformer turns-ratio test. A typical excitation and ratio
test connection is shown in Figure 2. Transformer bushing CT connections for Delta and Y
transformers are shown in Figure 3 and Figure 4, respectively.
Figure 2. Typical EZCT-2000A Excitation and Ratio Test Cable Connection
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Figure 3. Bushing CT Connection on Delta Transformer
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Figure 4. Bushing CT Connection on Y Transformer
EZCT-2000A USER’S MANUAL REV 1
3.2 EZCT-2000A X Input Voltage Warning
The EZCT-2000A X output terminals are rated to 2,000 Vac working voltage. Any voltage present
at these terminals above 2,000 Vac may damage the X sense circuitry, cause false readings, or
both. An example of a typical situation where this may occur is shown in Figure 5 below.
Figure 5. Sample CT Name Plate
For the above example CT, the turns ratio between X1-X4 is 3150 to 1. The turns ratio between
X1-X2 is 400 to 1. The turns ratio between X1-X4 and X1-X2 is 7.88 (3150/400). If a test voltage
of 300 Vac is applied to the X1-X2 terminals, a voltage of 2,364 Vac (300 Vac x 7.88) will be
induced at the X1-X4 terminals. If all the test leads are connected to the EZCT-2000A and the
excitation test is performed on the X1-X2 terminals, the voltage induced at the X1-X4 terminals
will exceed 2,000 Vac as the voltage across the X1-X2 terminals increases above 250 Vac. A
“Flash-Over” condition may occur and damage the EZCT-2000A. In this case, the user should
only connect the X1-X2 leads and run its excitation test, then connect the X4 lead before
running the X1-X4 excitation test.
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3.3 Performing Tests
3.3.1. Entering Test Record Header Information
You can enter the test record header information before performing tests. The record header
includes identifying information such as the company, station, circuit, model number, etc. Once
the header information has been entered, it will apply to all subsequent test records. To enter
the header information:
a. When the unit is turned on and the firmware has been loaded, you will be presented
with the “START-UP” menu as shown below:
1. RUN TEST 02/14/10
2. SETUP 10:14:25
3. TEST PLANS
4. DIAGNOSTIC
Press the [2] key (SETUP).
b. The following screen will be displayed:
1. RECORD ID
2. PRINT RECORD
3. RECORD DIRECTORY
4. SAVE/RES RECORD
5. ERASE RECORD
6. NEXT PAGE
Press the [1] key (RECORD ID)
c. The following screen will be displayed:
COMPANY:
vanguard
↑↓ TO POSITION
"enter" to accept
Type the company name using the alpha-numeric keypad.
When pressing a key, the corresponding number on the key will be displayed first.
Pressing the key again will display the first letter on the key. Pressing the key again will
display the second letter on the key. For example, to type the letter “A”, you must press
[2] key twice. To erase the character at the cursor position, press the [CLEAR] key.
the
Press the
∨ Contrast]
[PAPER ∧ Contrast] key to move to the next character. Press the [PAPER
key to move to the previous character. Press the [ENTER] key when you
are done typing the company name.
13
d. The following screen will be displayed:
STATION:
LAB
↑↓ TO POSITION
"enter" to accept
Type the station name using the alpha-numeric keypad and then press the [ENTER]
key.
e. The following screen will be displayed:
CIRCUIT:
CIRCUIT 1
↑↓ TO POSITION
"enter" to accept
EZCT-2000A USER’S MANUAL REV 1
Type the circuit information using the alpha-numeric keypad and then press the
[ENTER] key.
f. The following screen will be displayed:
MANUFACTURER:
ABB
↑↓ TO POSITION
"enter" to accept
Type the manufacturer name using the alpha-numeric keypad and then press the
[ENTER] key.
g. The following screen will be displayed:
MODEL:
EZCT2000A
↑↓ TO POSITION
"enter" to accept
Type the model information using the alpha-numeric keypad and then press the
[ENTER] key.
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h. The following screen will be displayed:
SERIAL NUMBER:
27001
↑↓ TO POSITION
"enter" to accept
Type the serial number using the alpha-numeric keypad and then press the [ENTER]
key.
i. The following screen will be displayed:
COMMENTS:
no comment
↑↓ TO POSITION
"enter" to accept
Enter any relevant comments using the alpha-numeric keypad and then press the
[ENTER] key.
j. The following screen will be displayed:
OPERATOR:
TA
↑↓ TO POSITION
"enter" to accept
Type the operator’s name using the alpha-numeric keypad and then press the [ENTER]
key. All header information will be saved, and you will be returned to the “START-UP”
menu.
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EZCT-2000A USER’S MANUAL REV 1
3.3.2. Performing Resistance, Excitation, and Ratio Tests
The following procedure describes the general steps for performing excitation, resistance, and
ratio tests.
a. When the EZCT-2000A is turned on, it will first go through a start-up cycle and load the
firmware. Then the “START-UP” menu will be displayed as shown below:
1. RUN TEST 02/14/10
2. SETUP 10:24:25
3. TEST PLANS
4. DIAGNOSTIC
Press the [1] key (RUN TEST) to start a test.
b. The following screen will be displayed:
1. Res, excit & ratio
2. excitation & ratio
3. excitation only
4. ratio only
5. resistance & excit
Select the test type by pressing the corresponding key ([1] - [5])
c. The following screen will be displayed:
SELECT TAP:
1. X1-X2
2. X1-X3
3. X1-X4
4. X1-X5
5. NEXT PAGE
Select the tap connection by pressing the corresponding key (
[1] - [4]). If the tap
connection is not listed, press the [5] key to view the next page of options.
d. If the selected test included an excitation test, the following screen will be displayed:
SELECT VOLTAGE RANGE:
1. 50V
2. 300V
3. 500V
4. 1200V
5. 2000V
Select a test voltage range by pressing the corresponding key (
[1] - [5]).
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REV 1 EZCT-2000A USER’S MANUAL
e. If the selected test included an excitation test, the following screen will be displayed:
SET TEST CURRENT:
1. 0.2A
2. 0.5A
3. 1A
4. 2A
5. 5A
6. 10A
Select the maximum test current for the excitation test by pressing the corresponding
key (
[1] - [6]
).
Most CT’s will saturate before the excitation current reaches 1A. To reduce
stress on CT’s, a maximum test current of 1A is recommended.
NOTE
f. If the selected test included a ratio test, the following screen will be displayed:
XFMR NAME PLATE RAT.
1. YES
2. NO
1. YES
Press the
[1]
key if you would like to enter the CT nameplate values. The
following screen will be displayed:
ENTER PLATE RATIO:
0 :
Type the first number using the keypad.
You can press the
Press the
[ENTER]
[CLEAR]
key. The following screen will be display ed:
key to restart a field entry if necessary.
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EZCT-2000A USER’S MANUAL REV 1
ENTER PLATE RATIO:
1000 : 0.0
Type the second number using the keypad and then press the [ENTER] key.
Continue to step g.
2. NO
Press the [2] key if you do not want to enter the CT nameplate values. Continue
to step g.
g. The following screen will be displayed:
ENTER TEST 1 NOTE:
_
↑↓ to position
"ENTER" TO ACCEPT
ENTER PLATE RATIO:
1000 : 5.0
Use the alpha-numeric keys on the keypad to enter a test note. The test note field is 20
characters long. One test note can be saved for each test.
When pressing a key, the corresponding number on the key will be displayed first.
Pressing the key again will display the first letter on the key. Pressing the key again will
display the second letter on the key. For example, to type the letter “A”, you must press
the [2] key twice. To erase the character at the cursor position, press the [CLEAR] key.
Press the
[PAPER ∨ Contrast]
[PAPER ∧ Contrast] button to move to the next character. Press the
key to move to the previous character. Press the [ENTER] key
when you are done typing the note.
h. The following screen will be displayed if the selected test included a resistance test:
calc err vs burden?
1. yes
2. no
Press the
[1] key (YES). Selecting this option will print the current ratio error table as
part of the tabulated test results. Please see item 19 in Figure 6.
i. The following screen will be displayed:
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REV 1 EZCT-2000A USER’S MANUAL
If you had selected a test current greater than 1 Amp in step e, the following
screen will be displayed:
NOTE
SATURATION CUR WILL
BE REDUCED TO 1 AMP.
(PRESS ANY KEY...)
Press any key to continue.
ENTER BURDEN VA:
(500.0 max)
0.0
Type the burden value using the keypad and then press the
j. The following screen will be displayed:
ENTER cos ϕ:
(0.00 - 1.00)
0.0
Type the Cos ϕ value using the keypad and then press the
k. The following screen will be displayed:
rated secondary cur:
1. 5A 2)1A
[ENTER]
[ENTER]
key.
key.
Select the rated secondary current by pressing the
19
[1]
key (5A) or
[2]
key (1A).
EZCT-2000A USER’S MANUAL REV 1
l. The following screen will be displayed showing a summary of the test parameters:
TEST 1 parameters:
1200V 1.0A x1-x2
"START" to begin
Press the
[START]
key to start the test.
m. If the selected test included a resistance test, the following screen will be displayed
momentarily:
CABLES ENERGIZED!
1200V 1.0A x1-x2
DC RESISTANCE TEST
The following screen will then be displayed:
CABLES ENERGIZED!
1200V 1.0A x1-x2
RESISTANCE = 215.1
Ω
The “HIGH VOLTAGE PRESENT” light will be illuminated to indicate that high
voltage is present.
NOTE
n. If the selected test included a ratio test, the following screen will be displayed
momentarily:
CABLES ENERGIZED!
1200V 1.0A x1-x2
I= 0.0004 AMPS
V= 34.2 VAC
The following screen will then be displayed:
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REV 1 EZCT-2000A USER’S MANUAL
RATIO TEST
V
= 79.5 VH = 0.3970
x
I=0.0532 RAT=+200.09
When the testing is finished, the test results graph will be displayed:
Press any key on the keypad to continue.
o. The following screen will be displayed:
print test results?
1. YES
2. NO
Press the [1] key (YES) if you would like to print the test results. The test results will be
printed on the thermal printer. A typical EZCT-2000A tabulated test report printout is
shown in Figure 6. Typical graphic reports are shown in Figure 7 and Figure 8.
Press the
[2] key (NO) if you do not want to print the test results.
p. The following screen will be displayed:
KEEP THIS TEST?
1. YES
2. NO
Press the
[1] key (YES) to keep the test results.
21
q. The following screen will be displayed:
TEST 1 SAVED
Press any key to continue.
r. The following screen will be displayed:
RUN ANOTHER TEST?
1. YES
2. NO
EZCT-2000A USER’S MANUAL REV 1
Press the [2] key (NO).
s. The following screen will be displayed:
SAVE THIS RECORD?
1. YES
2. NO
Press the
[1] key (YES) to save the record.
The following screen will be displayed momentarily:
SAVING RECORD...
PLEASE WAIT...
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REV 1 EZCT-2000A USER’S MANUAL
t. The following confirmation screen will then be displayed:
RECORD NUMBER 1
has been saved!
The test record number is automatically assigned to each test record stored in
the EZCT-2000A’s Flash EEPROM.
NOTE
Press any key to return to the “START-UP” menu.
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EZCT-2000A USER’S MANUAL REV 1
Figure 6. Typical EZCT-2000A Tabulated Report Printout
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REV 1 EZCT-2000A USER’S MANUAL
Table 3. Descriptions of Tabulated Test Results Elements
Item
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Description
Test record header information.
The EZCT-2000A X terminals (taps) that were selected for this test.
Test note for this particular test. The test note can be up to 20-characters long.
Recorded excitation current readings on the CT secondary winding.
Recorded excitation test voltages applied to the CT secondary winding.
Impedance calculated at each data point.
The voltage, current, and impedance data points recorded on the graph grid-marks.
Measured DC resistance value of CT under test.
ASA 10/50 knee point voltage and excitation current
(This is equivalent to the IEC 10/50 and ANSI 10/50 knee point voltage and excitation current)
IEEE 30° knee point voltage and excitation current.
IEEE 45° knee point voltage and excitation current.
CT nameplate turns ratio.
Measured turns ratio.
Turns ratio percentage error.
Polarity of the CT.
Measured phase angle.
Excitation voltage used in CT turns ratio test.
Excitation current in turns ratio test.
Current ratio error table. This information will be printed only if you selected “YES” for the “CALC ERR
VS BURDEN?” option when running a test. See section 3.3.2, step h for details.
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EZCT-2000A USER’S MANUAL REV 1
Knee Point Marker
Figure 7. Typical EZCT-2000A Graphic Report
Figure 8. Typical EZCT-2000A Graphic Report with Multiple Plot Curves
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