CVT-765 Capacitor Voltage Transformer Ratio Tester USER’S MANUAL Vanguard Instruments Company, Inc. 1520 S. Hellman Ave.
CVT-765 USER’S MANUAL REV 1 SAFETY SUMMARY FOLLOW EXACT OPERATING PROCEDURES Any deviation from procedures described in this User’s Manual may create one or more safety hazards, damage the CVT-765, damage the test transformer, or cause errors in the test results. Vanguard Instruments Company, Inc. assumes no liability for unsafe or improper use of the CVT-765. SAFETY WARNINGS AND CAUTIONS The CVT-765 shall be used only by trained operators. All transformers under test shall be offline and fully isolated.
REV 1 CVT-765 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 Technical Specifications ......................................................
CVT-765 USER’S MANUAL REV 1 CONVENTIONS USED IN THIS DOCUMENT This document uses the following conventions: • A key, switch, or knob on the CVT-765 is indicated as [KEY], [SWITCH], [KNOB]. • Menu names are referenced as “MENU NAME” • CVT-765 LCD screen output is shown as: 1. 2. 3. 4. 5. • OPTION OPTION OPTION OPTION OPTION 1 2 3 4 5 When instructions are provided, the menu item that should be selected is outlined with a rectangle as shown below (option 3 should be selected): 1. OPTION 1 2.
REV 1 CVT-765 USER’S MANUAL 1.0 INTRODUCTION 1.1 General Description and Features The Vanguard CVT-765 is a microprocessor-based, single phase, automatic, transformer turnsratio tester. This portable test unit is specifically designed to measure the turns-ratios of Capacitor Voltage Transformers (CVT’s). The CVT-765 determines the transformer turns-ratio using the IEEE C57.12.90 measuring method.
CVT-765 USER’S MANUAL 1.2 REV 1 Technical Specifications Table 1. CVT-765 Technical Specifications TYPE Portable, automatic, CVT, VT, PT turns-ratio tester PHYSICAL SPECIFICATIONS Dimensions: 19.5" x 12" x 17" D (49.5 cm x 30.5 cm x 43.2 cm) Weight: 55 lbs. (24.9 Kg) INPUT POWER 100-120 Vac or 220-240 Vac (selectable), 50/60 hz MEASUREMENT METHOD ANSI/IEEE C57.12.90 RATIO MEASURING RANGE 75 - 15,000 (5 digit resolution) TURNS-RATIO ACCURACY PHASE ANGLE READING 75 - 4,999: ±0.25%, 5,000 - 9,999: ±0.
REV 1 1.3 CVT-765 USER’S MANUAL Controls and Indicators The CVT-765 controls and indicators are shown in Figure 1. A leader line with an index number points to each control and indicator, which is cross-referenced to a functional description in the corresponding table. The purpose of the controls and indicators may seem obvious, but users should familiarize themselves with them before using the CVT-765. Accidental misuse of the controls will usually cause no serious harm.
CVT-765 USER’S MANUAL REV 1 Table 2.
REV 1 CVT-765 USER’S MANUAL 2.0 PRE-TEST SETUP 2.1 Operating Voltages The CVT-765 can be operated from 100-120 Vac or 220-240 Vac. The proper voltage can be set using the voltage selection switch on the front panel (see Figure 1). 2.2 LCD Screen Contrast Control To increase the LCD screen contrast, press and hold the [Contrast ∧] key for two seconds. Release the button when the desired contrast level has been reached.
CVT-765 USER’S MANUAL 3.0 REV 1 OPERATING PROCEDURES The CVT-765 should always be grounded with the provided ground cable before connecting H and X cables. The transformer bushings should also be grounded before connecting test leads to the transformer. This will prevent inducing any voltages into the CVT-765. All transformer bus connections must be removed, and the transformer must be isolated before performing any tests. 3.1 Connection Diagram Figure 2.
REV 1 3.2 CVT-765 USER’S MANUAL Setting the Date and Time To set the date and time: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. 2. 3. 4. RECORD ID SET 50/60 HZ DISPLAY RECORD SAVE/RESTORE RECORD 5. SET TIME 6. set language Press the [5] key (SET TIME). c. The following screen will be displayed: ENTER DATE MM-DD-YY Enter the date using the alpha-numeric keypad. d.
CVT-765 USER’S MANUAL 3.3 REV 1 Setting the Interface Language Follow the steps below to set the interface language (English, Spanish, or Turkish): a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP) b. The following screen will be displayed: 1. 2. 3. 4. 5. RECORD ID SET 50/60 HZ DISPLAY RECORD SAVE/RESTORE RECORD SET TIME 6. set language Press the [6] key (SET LANGUAGE) c. The following screen will be displayed: 1. ENGLISH 2.
REV 1 3.4 CVT-765 USER’S MANUAL Setting the Frequency (50 or 60 Hz) Follow the steps below to set the preferred frequency: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. 3. 4. 5. 6. SET 50/60 HZ DISPLAY RECORD SAVE/RESTORE RECORD SET TIME set language Press the [2] key (SET 50/60 HZ). c. The following screen will be displayed: 1. 60 Hz 2.
CVT-765 USER’S MANUAL 3.5 REV 1 Performing Tests 3.5.1. 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, manufacturer, etc. Once the header information has been set, it will apply to all subsequent test records. To enter the header information: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2.
REV 1 CVT-765 USER’S MANUAL key to move to the previous character. Press the [ENTER] key when you are done typing the company name. d. The following screen will be displayed: STATION: _ ↑ /↓ 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: _ ↑ /↓ TO POSITION "ENTER" TO ACCEPT Type the circuit information using the alpha-numeric keypad and then press the [ENTER] key. f.
CVT-765 USER’S MANUAL REV 1 g. The following screen will be displayed: MODEL: _ ↑ /↓ TO POSITION "ENTER" TO ACCEPT Type the transformer’s model information using the alpha-numeric keypad and then press the [ENTER] key. h. The following screen will be displayed: SERIAL NUMBER: _ ↑ /↓ TO POSITION "ENTER" TO ACCEPT Type the transformer’s serial number using the alpha-numeric keypad and then press the [ENTER] key. i.
REV 1 j. CVT-765 USER’S MANUAL The following screen will be displayed: OPERATOR: _ ↑ /↓ 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.
CVT-765 USER’S MANUAL REV 1 3.5.2. Performing a Transformer Test Follow the steps below to test a transformer: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [1] key (TEST TRANSFORMER). b. The following screen will be displayed: TEST WINDING: 1.X1-X3 3.Y1-Y3 5.Z1-Z3 2.X2-X3 4.Y2-Y3 6.Z2-Z3 Select the winding by pressing the corresponding numeric key on the keypad. c. The following screen will be displayed: NAME PLATE VOLTAGE? 1. YES 2.
REV 1 CVT-765 USER’S MANUAL 1. YES Press the [1] key (YES) if you would like to enter the transformer name plate voltage values. The following screen will be displayed. NAME PLATE VOLTAGE: H : X 0 : Type the H winding name plate voltage value using the numeric keypad. The screen will be updated as shown below: NAME PLATE VOLTAGE: H : X 2,400 : Press the [ENTER] key.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: PRESS AND HOLD ARM SWITCH TO TEST OR "STOP" TO ABORT Press and hold the [ARM] switch to initiate the test. e. The following screen will be displayed while the test is being performed: test in progress please wait... Continue to hold down the [ARM] switch. Testing will continue, and the test results will be displayed on the LCD screen when testing has finished: RATIO +10.004 PHASE = 0.02° %DIFF 0.
REV 1 CVT-765 USER’S MANUAL f. The following screen will be displayed: KEEP THIS READING? 1. YES 2. NO Press the [1] key (YES) to save the reading. g. The following screen will be displayed: TEST SAVED Press any key to continue. NOTE The above screen will be displayed if there is currently no data in the unit’s memory buffer. If a test was previously performed or a test record was restored from Flash EEPROM or from a Flash drive, the following screen will be displayed instead: PREVIOUS DATA IN BUF 1.
CVT-765 USER’S MANUAL REV 1 h. The following screen will be displayed: RUN ANOTHER TEST? 1. YES 2. NO 3. REPEAT PREV. TEST Press the [2] key (NO). i. The following screen will be displayed: SAVE THIS RECORD? 1. YES 2. NO Press the [1] key (YES) to save the test record to the unit’s Flash EEPROM. j. The following screen will be displayed momentarily: SAVING RECORD... PLEASE WAIT...
REV 1 3.6 CVT-765 USER’S MANUAL Working With Test Records 3.6.1. Viewing the Contents of the Working Memory Whenever a test is performed or a test record is retrieved, the data is stored in the CVT-765’s working memory. You can view the test data using the steps below: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. 4. 5. 6.
CVT-765 USER’S MANUAL REV 1 3.6.2. Saving Test Results to a Test Record After performing a test, the user is presented the option to save the test results to the unit’s Flash EEPROM or to a USB Flash Drive. If the test results are not saved immediately after performing a test, they will still remain in the working memory and can be saved later, as long as a new test has not been performed and the unit has not been turned off.
REV 1 CVT-765 USER’S MANUAL c. The following screen will be displayed: 1. RESTORE RECORD 2. 3. 4. 5. SAVE RECORD RECORD DIRECTORY ERASE RECORD COPY to THUMB DRIVE Option 5 (COPY TO THUMB DRIVE) will be listed only if a USB Flash drive is connected to the CVT-765. NOTE Press the [2] key (SAVE RECORD). If a USB Flash drive is connected to the unit, continue to step d. If a USB Flash drive is NOT connected to the unit, continue to step e. d. The following screen will be displayed: 1. SAVE INTERNALLY 2.
CVT-765 USER’S MANUAL REV 1 e. The following screen will be displayed: RECORD NUMBER 5 HAS BEEN SAVED! Press any key to return to the “START-UP” menu.
REV 1 CVT-765 USER’S MANUAL 3.6.3. Restoring a Test Record From Flash EEPROM Use the steps below to restore a test record from the CVT-765’s Flash EEPROM to the working memory: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. DISPLAY RECORD 4. SAVE/RESTORE RECORD 5. SET TIME 6. set language Press the [4] key (SAVE/RESTORE RECORD). c.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: RESTORE RECORD 1.ENTER RECORD NUMBER 2.SCROLL TO SELECT If you have a USB Flash drive inserted in the CVT-765’s “USB MEM” port, the following screen will be displayed instead of the above screen: NOTE 1.INTERNAL STORAGE 2.THUMB DRIVE Press the [1] key (INTERNAL STORAGE). The following screen will be displayed: RESTORE RECORD 1.ENTER RECORD NUMBER 2.SCROLL TO SELECT Continue with the steps below. 1.
REV 1 CVT-765 USER’S MANUAL 1.2. The following screen will be displayed: RECORD RESTORED! DISPLAY RECORD? 1.YES 2.NO Press the [1] key (YES) to display the test record. 1.3. The basic information about the restored test record will be displayed as shown: SINGLE PHASE Num Tests: 1 04/15/11 09:52:50 Press the [Contrast ∨] key. The test record details will be displayed as shown: 1 SINGLE PHASE 7440 volts RATIO %DIFF 10.004 0.04 Press the [STOP] key to return to the “START-UP” menu.
CVT-765 USER’S MANUAL REV 1 Press the [Contrast ∧] button or the [Contrast ∨] key to display the next or previous test record, respectively. The basic test record information will be displayed as shown: #1 04/15/11 09:52 SINGLE PHASE 1 TESTS When you have located the test record that you would like to restored, press the [ENTER] key. Continue to step 1.2 on page 26.
REV 1 CVT-765 USER’S MANUAL 3.6.4. Restoring a Test Record From a USB Flash Drive Use the steps below to restore a test record from a USB Flash drive to the CVT-765’s working memory: a. Make sure the USB Flash drive containing the test record(s) is inserted in the CVT-765’s USB Flash drive port (“USB MEM” port). Then start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: 1.INTERNAL STORAGE 2.THUMB DRIVE Press the [2] key (THUMB DRIVE). e. The following screen will be displayed: RESTORE THUMB DRIVE REC_ Type the record number that you would like to restore using the alpha-numeric keypad and then press the [ENTER] key. f. The test record will be restored to the unit’s working memory and the following screen will be displayed: REC_000 restored! DISPLAY RECORD? 1.YES 2.
REV 1 CVT-765 USER’S MANUAL Press the [Contrast ∨] key. The test record details will be displayed as shown below: 1 SINGLE PHASE 7440 volts RATIO %DIFF 10.004 0.04 Press the [STOP] key to return to the “START-UP” menu. The restored test record will remain loaded in the working memory.
CVT-765 USER’S MANUAL REV 1 3.6.5. Copying Test Records to a USB Flash Drive Use the steps below to copy one or all test records from the unit’s Flash EEPROM to a connected USB Flash drive: a. Make sure a USB Flash drive is connected to the unit’s “USB MEM” port, and then start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. DISPLAY RECORD 4. SAVE/RESTORE RECORD 5.
REV 1 CVT-765 USER’S MANUAL d. The following screen will be displayed: COPY REC TO THUMB DRV 1.COPY SINGLE RECORD 2.COPY ALL RECORDS 1. COPY SINGLE RECORD Press the [1] key (COPY SINGLE RECORD) to copy a single test record from the CVT-765’s Flash EEPROM to the connected USB Flash drive. The following screen will be displayed: ENTER RECORD NUMBER TO COPY TO FLASH DRV NUMBER: Type the record number using the alpha-numeric keypad and then press the [ENTER] key.
CVT-765 USER’S MANUAL REV 1 ALL RECORDS HAVE BEEN TRANSFERRED TO THUMB DRIVE! Press any key to return to the “START-UP” menu.
REV 1 CVT-765 USER’S MANUAL 3.6.6. Viewing the Test Record Directory Use the steps below to browse through a directory of the test records stored in the CVT-765’s Flash EEPROM memory: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP) b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. DISPLAY RECORD 4. SAVE/RESTORE RECORD 5. SET TIME 6. set language Press the [4] key (SAVE/RESTORE RECORD). c.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: RECORDS DIRECTORY "UP" TO SCROLL FWD "DWN" TO SCROLL RVS Press the [Contrast ∧] or [Contrast ∨] key to scroll through the test record directory. The test record header will be displayed as shown: SINGLE PHASE Num Tests: 1 04/15/11 09:52:50 You can continue to scroll through the record directory by pressing the [Contrast ∧] and [Contrast ∨] keys. Press the [STOP] key to return to the “START-UP” menu.
REV 1 CVT-765 USER’S MANUAL 3.6.7. Erasing Test Records from the Flash EEPROM Follow the steps below to erase test records from the Flash EEPROM: a. Start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. DISPLAY RECORD 4. SAVE/RESTORE RECORD 5. SET TIME 6. set language Press the [4] key (SAVE/RESTORE RECORD). c. The following screen will be displayed: 1.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: ERASE RECORD 1.ERASE SINGLE REC. 2.ERASE ALL RECORDS "STOP" TO EXIT If you have a USB Flash drive inserted in the CVT-765’s “USB MEM” port, the following screen will be displayed instead of the above screen: NOTE 1.ERASE INTERNAL REC 2.ERASE THUMB DRV REC Press the [1] key (ERASE INTERNAL REC). The following screen will be displayed: ERASE RECORD 1.ERASE SINGLE REC. 2.ERASE ALL RECORDS "STOP" TO EXIT Continue with the steps below.
REV 1 CVT-765 USER’S MANUAL Type the record number that you would like to erase using the alpha-numeric keypad and then press the [ENTER] key. If you do not know the test record number, you can first view the test record directory using the instructions in section 3.6.6. The following screen will be displayed while the record is being erased: ERASing record PLEASE WAIT...
CVT-765 USER’S MANUAL REV 1 ERASing recordS PLEASE WAIT... The following screen will be displayed when all test records have been completely erased: RECORDS ERASED! Press any key to return to the “START-UP” menu.
REV 1 CVT-765 USER’S MANUAL 3.6.8. Erasing Test Records from a USB Flash Drive Follow the steps below to erase test records from a USB Flash drive: a. Make sure a USB Flash drive is connected to the unit’s “USB MEM” port, and then start from the “START-UP” menu: 1. TEST TRANSFORMER 2. SETUP TIME: DATE: 15:16:17 05/17/11 Press the [2] key (SETUP). b. The following screen will be displayed: 1. RECORD ID 2. SET 50/60 HZ 3. DISPLAY RECORD 4. SAVE/RESTORE RECORD 5. SET TIME 6.
CVT-765 USER’S MANUAL REV 1 d. The following screen will be displayed: 1.ERASE INTERNAL REC 2.ERASE THUMB DRV REC Press the [2] key (ERASE THUMB DRV REC). e. The following screen will be displayed: ERASE RECORD 1.ERASE SINGLE REC. 2.ERASE ALL RECORDS "STOP" TO EXIT 1. ERASE SINGLE REC. Press the [1] key (ERASE SINGLE REC.) to erase a single test record from the connected USB Flash drive.
REV 1 CVT-765 USER’S MANUAL 2. ERASE ALL RECORDS Press the [2] key (ERASE ALL RECORDS) to delete all test records from the connected USB Flash drive. The following warning screen will be displayed: ERASE ALL THUMB DRIVE RECORDS! ARE YOU SURE? "ENTER" TO CONTINUE. Press the [STOP] key if you do not want to erase all the test records. You will be returned to the “START-UP” menu. Press the [ENTER] key to proceed with deleting all the test records from the connected USB Flash drive.
1520 S. Hellman Ave • Ontario, CA 91761 • USA Phone: 909-923-9390 • Fax: 909-923-9391 www.vanguard-instruments.com Copyright © 2011 by Vanguard Instruments Company, Inc. CVT-765 User’s Manual • Revision 1.
