Haefely Test AG TTR 2796 Operating Instructions Manual
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Haefely Test AG TTR 2796 Operating Instructions Manual

Transformer turns ratio meter
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Operating Instructions

HAEFELY TEST AG
TTR 2796
Transformer Turns
Ratio Meter
Version 0.7

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Summary of Contents for Haefely Test AG TTR 2796

  • Page 1: Operating Instructions

    Operating Instructions HAEFELY TEST AG TTR 2796 Transformer Turns Ratio Meter Version 0.7...
  • Page 2 Title Operating Instructions TTR 2796 Transformer Turns Ratio Meter Date 10-2010 Authors RSch Layout Revision History V0.7 22/10/10 RSch Initial release of the document...
  • Page 3 The software version is reported at power-up. Note HAEFELY TEST AG has a policy of continuing improvement on all their products. The design of this instrument will be subject to review and modification over its life. There may be small discrepancies between the manual and the operation of the instrument, particularly where software has been upgraded in the field.
  • Page 4 Manual Conventions In the manual, the following conventions are used: Indicates a matter of note - if it refers to a sequence of operations, failure to follow the instructions could result in errors in measurement. Indicates hazards. There is a risk of equipment damage or personal injury or death.

  • Page 5: Table Of Contents

    Contents Introduction Introduction ....................3 Scope of Supply................... 3 Technical Data ..................... 4 1.3.1 Standard Features................4 1.3.2 Physical and Environmental Specifications ........4 1.3.3 Measuring System................5 1.3.4 User Interface System..............5 1.3.5 Tap Changer Interface ..............5 1.3.6 Printer paper Specification ..............
  • Page 6 Running A Test ..................34 Errors & Warnings While Testing ............... 35 Testing Stage 1 - Pretest stage..............36 Testing an Untapped Transformer ............. 37 Testing A Tapped Transformer using the Tap Changer Button....38 Options When the Test has Completed ............. 38 Saving the Test Results ................

  • Page 7: Introduction

    RS-232-to-USB communications link. The TTR 2796 uses a simple and intuitive user interface to make the process of testing as easy as possible. It guides the user through the measurement of turns ratio, phase angles and phase displacement.

  • Page 8: Technical Data

    On receipt of the unit check that all items have been delivered. Also check that the correct power cord for your location has been supplied. In the event of missing or damaged parts please contact you local sales representative stating the serial number and type of the instrument and the sales order number. Technical Data 1.3.1 Standard Features...

  • Page 9: Measuring System

    1.3.3 Measuring System Test Voltages: 2.5VRMS, 25VRMS, 100VRMS, 250VRMS Nominal Maximum Input Voltage: 1000V for 5 secs Energizing Frequency: 50Hz or 60Hz depending on local mains Turns Ratio Measuring 0.8 to 20,000 Range: Turns Ratio Resolution: 5 digits Ratio Accuracy @ 25V @ 100V @ 250V...

  • Page 10: Printer Paper Specification

    1.3.6 Printer paper Specification Paper Type: Thermal Roll Paper Width: 58mm +/- 1mm Maximum Roll Diameter: Outer : 50mm, Inner : 10mm Introduction...

  • Page 11: Safety

    Do not operate the TTR 2796 from a variable power supply. The TTR 2796 adjusts to the local line voltage at start-up. Changing the line voltage while the unit is in operation may cause damage to the unit and to the test object Hazardous voltages exist on the terminals of the instrument when the “Active”...
  • Page 12 instrument and represents a significant safety hazard for personnel Never operate the equipment in an explosive environment or where there are flammable gases or fumes Safety...

  • Page 13: Operation Elements

    Operation Elements Front panel Figure 1 : Instrument frontpanel Printer HV cable “H” connection - when the Active lamp is lit, voltage is present on the output LV cable “X” connection - when the Active lamp is lit, voltage may be present on the terminals Tap changer interface connector RS-232 communications port.

  • Page 14: Printer

    Printer The printer on the system is a thermal roll type printer and will only operate with thermal paper. See the specifications for details or the required paper. The supplied paper has a paper low warning indication on it. When the paper is getting towards the end of the roll, there are colored streaks (usually pink or red) on the paper.

  • Page 15: Connection And Setup

    The measurement of turns ratio requires sensitive voltage measurements to be made. It is necessary to minimize the pick-up and cross-coupling on the cables if the most accurate result possible is to be achieved. The following guidelines should be followed. The TTR 2796 has circuitry to minimize the effects of common-mode and high- Connection and Setup...

  • Page 16: Cable Fixing

    frequency interference, however good practice in the setting up of the test systems will aid the quality of the measurements made. Ensure, as far as is feasible, that any sources of interference are eliminated from the test area. Equipment such as welding sets and phase-angle furnace controllers should be switched off if at all possible.

  • Page 17: Single Phase Transformers

    Single Phase Transformers To connect to a single-phase transformer using the standard three-phase cable set, the cables must be connected to the unit, using the extension leads if required. Ensure that the connectors are locked fully home. The connections should be made as follows: Transformer Terminal TTR Connection ANSI, IEEE...

  • Page 18: Three Phase Transformers

    Three Phase Transformers Connecting to three phase transformers depends on whether the transformer is equipped with neutral connections on primary or secondary. If there is no primary neutral connection, the H0 lead (Blue lead, Green Plug) is left unconnected. It must be placed in such a way that it is isolated from earth and from any other connection, and that there is no possibility of it being...
  • Page 19 Note the CT measurement mode is an indication only mode, for checking if saturation is the problem. It must not be used for measurement. CTs are measured by energizing the secondary and measuring on the primary. For “ring” type current transformers connect the system as follows: Figure 8 : Connecting to a Ring CT...

  • Page 20: Bushing Current Transformers

    Bushing Current Transformers Figure 10 : Connecting to Single Phase BCT It is possible to test bushing current transformers once they are in-situ. This relies on the minimal loading of the test circuit by the secondary measurement system of the TTR instrument. The primary (or secondary depending on the configuration) connections of the transformer should also be jumped out to create a shorted turn and minimize the inductance of the secondary (or primary).
  • Page 21 Figure 11 : Connecting to three phase BCT Connection and Setup...

  • Page 22: Transformer Look Up Tables

    Due to similar reasons the voltage ratio VR and the turns ratio TR is –depending on the winding configuration and phase rotation of the transformer – not always equal. The TTR 2796 therefore internally corrects the entered rated voltages (VR) with the “VR/TR” factor and displays automatically the correct ratio deviation which is calculated out of the rated voltages (boilerplate voltages) as reference and the actually measured (and corrected) ratio value.

  • Page 23: Tables

    4.9.2 Tables HV Winding LV Winding VR/TR Phase Displacement A:a = 0 A:b = 8 A:c = 4 A:-a = 6 A:-b = 2 A:-c = 10 Notes: HV Winding LV Winding VR/TR 1/3 Phase Displacement A:a = 1 A:b = 9 A:c = 5 A:-a = 7 A:-b = 3...
  • Page 24 HV Winding LV Winding VR/TR Phase Displacement A:a = 0 A:b = 8 A:c = 4 A:-a = 6 A:-b = 2 A:-c = 10 Notes: HV Winding LV Winding VR/TR Phase Displacement A:a = 0 A:b = 8 A:c = 4 A:-a = 6 A:-b = 2 A:-c = 10...
  • Page 25 HV Winding LV Winding VR/TR Phase Displacement A:a = 0 A:b = 8 A:c = 4 A:-a = 6 A:-b = 2 A:-c = 10 Notes: Alternatively treat as Y-Y HV Winding LV Winding VR/TR 2/3 Phase Displacement A:a = 1 A:b = 9 A:c = 5 A:-a = 7...

  • Page 26: Control Knob

    Control Knob Control Knob The control knob is used once to scroll the selected line item: Rotate the knob to the left and the selector moves down, ..rotate to the right and the selector moves up. To change or edit the selected line item – press (PUSH) the knob..the system then enters an edit screen and allows the value to be edited.
  • Page 27 By rotating the knob the value can be increased respectively decreased. The cursor jumps to the next edit-field by pressing the knob. Jump one field back by pressing “PREVIOUS”. “DELETE” sets the edit-field back to default (0). List By rotating the knob the entry in the list can be selected. By pressing the knob the selected entry is taken over and the system returns back up to the superior parameter selection list.

  • Page 28: Startup

    Startup Startup After switching on the system it enters the Startup display: The serial number of this instrument Serial No. The Version of the actual used firmware (system software) FirmWare Version The date of the last factory calibration of the instrument Last Calibration After 3 seconds the following display will appear: With the soft keys in the bottom line the single sub-menus can be entered:...

  • Page 29: Setting Up Tests

    Setting Up Tests Setting Up Tests To set-up a new test on the system or to load a saved test, the set-up menu should be selected from the startup display. Press “UP” until the leftmost button indicates “SETUP”. Press this button and the system will enter the setup menu.
  • Page 30 The Phase displacement is only displayed if a three-phase transformer configuration has Ph Displacement been set (both HV Config and LV Config have been set). It allows the user to set the phase displacement of the transformer, or to select automatic determination of the phase displacement.

  • Page 31: Setting Up Transformer Configuration

    To change a parameter for the test, rotate the control knob unit the required parameter is highlighted and press it to select the option. The system allows the value to be edited. When the parameter has been edited, the system returns to the parameter selection list.

  • Page 32: Setting Test Voltage

    displacement automatically by the TTR is not infallible. The voltage ratios for some transformer configurations can be overlapping for certain factors/ratios and this causes the TTR sometimes too choose the wrong one or to display: “unable to determine the transformer configuration”. If this occurs, the configuration has to be set manually. The Automatic determination should not be used with Zig-zag windings without a neutral, while it cannot distinguish between a Delta (D) winding and a Zig-zag (Z) winding.
  • Page 33 Setting up a Transformer with Regularly Spaced Taps A transformer with regularly spaced taps is a transformer where the output voltages on the various taps differ by the same amount between adjacent taps. This is found in applications such as a tap changer type voltage stabilizer where each tap provides a specific amount of adjustment from the nominal value.
  • Page 34 Example 2 A transformer with 9 equally spaced taps, numbered 1 to 9. The nominal output is the middle one. Each tap gives an adjustment of 100V, with a nominal output voltage of 1kV from a 6.6KV primary thus Primary Secondary Voltage Voltage...

  • Page 35: Setting Up A Transformer With Irregularly Spaced Taps

    0.265kV 0.27kV 0.275kV 0.28kV Using Tap stepping entered in percentage set: “HV Nom Voltage” = 1kV “HV Nom Voltage” = 0.24KV “Total Taps” = 16 (Nominal output plus 15 additional) “Bot Tap Number” = -7 “Nom Tap Number” “Tap Setup” = LV “Step Tap to Tap”...

  • Page 36: Loading A Stored Setup For Use

    Each tap is indicated with the tap number, the HV voltage and LV voltage. To set the voltage for a particular tap, turn the knob until the required tap is highlighted. Clicking the knob will allow the user to enter first the HV and then the LV voltage for that tap.
  • Page 37 enter the required number as described in section 4.3. If there is no available memory, the system will report that it cannot save the data. Once the data has been saved into the memory, the system will display a message box confirming the operation.

  • Page 38: Running A Test

    Running A Test Running A Test Before connecting the instrument to the transformer, make sure that the transformer is fully disconnected from both its supply and load and ensure that it is fully de-energized. Ensure that the instrument is correctly connected to the transformer - the ‘X’ cables must be connected to the low voltage side, the ‘H’...

  • Page 39: Errors & Warnings While Testing

    The user has four menu options available: starts the measurement. Start brings the user to the setup of the “Device Under Test” Trafo brings the user to the memory, which might contain stored measurement results and Memory setups. brings the user to the general settings for the TTR (e.g. Time/Date/Debug-report, etc) Options Errors &...

  • Page 40: Testing Stage 1 - Pretest Stage

    repeat the test with a lower test voltage; in the second case, correct the connections to the transformer - exchange the primary with the secondary connections. If no connection errors are found, there may be short circuit within the transformer itself. A short or overload has been detected on the energization system preventing the Output Voltage Fail required output voltage from being applied to the transformer.

  • Page 41: Testing An Untapped Transformer

    Press cancel to clear the error box and the system will be ready to start testing again. If the problem persists, go to the OPTIONS menu and turn on the Debug Report. The system will report the measurements made in determining the transformer configuration and where in the process the measurement failed.

  • Page 42: Testing A Tapped Transformer Using The Tap Changer Button

    This toggles the Turns-ratio display to the Voltage-ratio and back again to Turns-ratio, V-Ratio when pressed again. This Pauses the measurement process part way through and shows a menu where the Save/Exit previous obtained data can either be saved or deleted followed by an exit or by pressing [Cancel] the Pause can be broken off and the measurements can be continued.

  • Page 43: Saving The Test Results

    Saving the Test Results When “Save/Exit” is pressed, the test results are saved into the next available memory location on the system. This is indicated on the screen using a message box. Press “Cancel” to return to the test menu. Press “Save”...

  • Page 44: Graphing The Test Results

    Nominal Tap Step Tap-Tap : 0.05kV For set of measurements on the transformer the instrument reports the measurements in this format: Tap -2 (1 of 5) 5.00kV 1.00kV Phase T-Ratio TR-Dev PH-Dev Current 5.0168 0.33 -0.7 48mA 5.0168 0.33 -0.8 55mA 5.0681 1.36...

  • Page 45: Memory Functions

    Memory Functions Memory Functions The MEMORY menu allows access to the information stored in the memory on the instrument. Two different types of information are stored in the memory: These memories just hold information on how the test is to be performed on a transformer Setup and what the taps are.

  • Page 46: Showing Memory Info On The Screen

    ******** TTR TEST REPORT ******* Transformer: DUT Serial No. Type: DUT Type Location: DUT Location Tested By: Operator Instrument: TETTEX2796 Serial No.: 1234-56-78 Date Of Test : 09/22/04 Time of Test : 08:23:45 Test Voltage : Auto Max Deviation: 0.5% Configuration: Auto 3ph HV Nom Volt : 3.0 kV...
  • Page 47 It indicates the date and time the test was performed, whether it is a test or a setup and the number of the memory it is stored in. Beneath that it shows the basic setup information for the stored in the memory Configuration YYn0 Test Voltage...
  • Page 48 If there are more taps than can be shown on the screen, rotating the control knob will scroll through the values. Press “OK” to return to the SHOW memory screen. Deleting Memory Information The highlighted memory can be deleted by pressing the “DELETE” button. This displays a message box asking for confirmation.

  • Page 49: Options

    10 Options 10.1 Options The general options of the TTR 2796 system can be set by selecting the “OPTION” button from the start-up screen. The following screen is shown: 10.2 Editable Options The used system date (dd-mm-yy) can be set.

  • Page 50: Fixed Options & Information

    10.3 Fixed Options & Information The following entries are factory set and therefore not changeable by the user: The identification of the instrument (TTR-2796) Instrument ID The serial number of this instrument (also shown in the stat-up screen) Serial No The Version of the actual used firmware (system software) FirmWare Version The date of the last factory calibration of the instrument...

  • Page 51: Remotecontrol

    (Straight through extension type) to connect to a standard 9 way RS-232 connector on a PC. For other connector configurations, a suitable adaptor should be used. The configuration of the serial port on the TTR 2796 is fixed at 9600 Baud, 8 bits, No parity, 1 Stop Bit.

  • Page 52: Remote Control System Error Codes

    +ERROR:nnnn:~: Data is encoded into the Fields: using a “big endian”, that is with the highest order bytes transmitted first. The Fields: are encoded as follows: Strings are transmitted with the terminating NULL character removed. The string should be scanned to determine the position of control characters.
  • Page 53 “maintain” command to indicate connection is to be maintained if it is not transmitting commands. If the host is not going to be transmitting data to the TTR for a period, it should send a “maintain” command every 2 seconds to keep the link active.

  • Page 54: Test Control Functions

    The instrument identification field is always returned as “TETTEX2796” irrespective of the instrument options, as these do not affect the operation of the system <Serial No> is the serial number of the instrument. This is passed as a text string. <Version>...
  • Page 55 +ERROR:090A:~: - Voltage is invalid +ERROR:0902:~: - Working Memory has data +ERROR:0300:~: - No update - test running The vector group is returned in the response as a confirmation. If there was a problem with the vector group, the function gives a negative response and returns the actual vector group being used.
  • Page 56 <HV Voltage> (float) is the voltage for the HV side of the nominal tap. Fields: This is entered in units of kV. <LV Voltage> (float) is the voltage for the LV side of nominal tap. +OK:~: - Nominal Tap voltages set OK Returns: +ERROR:0300:~: - No update - test running...
  • Page 57 Test:Info:Type This sets up the type of the UUT +T:I:T:<Type>:~: Structure: <Type> (string) is a 20 character type identification string. Fields: +OK:~: - The type has been updated. Returns: +ERROR:0902:~: - Working Memory has data +ERROR:0300:~: - No update - test running Comments: None Test:Info:Operator...
  • Page 58 Test:Measure:Halt This halts the measurement sequence +T:M:H:~: Structure: Fields: None +OK:Y:~: - Measurement Sequence is being halted Returns: +OK:H:~: - Measurement sequence already halted. Comments: None Test:Measure:Query This returns the current state of the measurement system, and the last results gathered. +T:M:Q:~: Structure: Fields:...
  • Page 59 Test:Results:Setup Returns the basic setup parameters for the last test performed. +T:R:S:~: Structure: Fields: None +OK:<VectorGroup>:<Voltage>:<HVNomVoltage>: Returns: <LVNomVoltage>:<NumTaps>:<BotTap>:<NomTap>: <StepVal>:<MeasTap>:~: <VectorGroup> (integer) is the vector group of the transformer under test. This defines the configuration of the transformer and the phase displacement. Bits 15-12 indicate the HV winding configuration, bits 11-8 indicate the LV winding configuration and bits 7-0 indicate the phase displacement.
  • Page 60 <Type> (string) is the 20 character manufacturers type code <Operator> (string) is the 20 character operator code <Deviation> (float) is the maximum acceptable turns ratio deviation. <TimeDate> (float) is the Time and Date of the test. Comments: None Test:Results:Taps This returns the result for the individual taps on the transformer. +T:R:T:<TapNum>:~: Structure: <TapNum>...

  • Page 61: Memory Control Functions

    +ERROR:0907:~: - The value of <TapNum> is out of range +ERROR:090E:~: - The value of <NumTap> is valid, but that tap has not been measured. This will occur if the test was halted before completion <HV> (float) is the boilerplate HV side voltage for this tap <LV>...
  • Page 62 <MemNo> (integer) is the number of the memory to be checked. It is in the Fields: range 0 to 100 (0x0000 to 0x0064). +OK:F:~: - Memory <MemNo> is free Returns: +OK:U:~: - Memory <MemNo> is used +ERROR:0903:~: - <MemNo> is out of range +ERROR:0904:~: - Memory <MemNo>...
  • Page 63 +ERROR:0905:~: - <MemNo> is out of range If the command is called with <MemNo> = 0, when the response is received from the TTR, Comments: it indicates which memory was actually used to store the data. Memory:Memory This copies the content of the specified memory to the working memory. +M:M:<MemNo>:~: Structure: <MemNo>...
  • Page 64 +OK:<VectorGroup>:<Voltage>:<HVNomVoltage>: Returns: <LVNomVolatge>:<NumTaps>:BotTap>:<NomTap>: <StepVal>:<MeasTap>:~: - Memory read OK +ERROR:0903:~: - Memory has no data +ERROR:0904:~: - Memory Corruption detected +ERROR:0905:~: - Specified memory is out of range <VectorGroup> (integer) is the vector group of the transformer under test. This defines the configuration of the transformer and the phase displacement.

  • Page 65: System Setup And Calibration

    <Location> (string) is the 20 character unit location code <Type> (string) is the 20 character manufacturers type code <Operator> (string) is the 20 character operator code <Deviation> (float) is the maximum acceptable turns ratio deviation. <TimeDate> (DateTime) is the time and date the test was performed. Comments: None Memory:Read:Taps...
  • Page 66 calibration enable jumper of the processor board within the TTR. This requires the unit to be opened and therefore will invalidate the existing calibration. The system setup flags option is used to set options on the system that could affect the operation of the unit; there are two flags: 0x0001 System has printer.
  • Page 67 +S:D:<CalDate>:<NextCalDate>:~: Structure: <CalDate> (TimeDate) is the date and time the calibration was performed. Fields: <NextCalDate> is the date and time the next calibration is due. +OK:~: - The dates and times were set successfully Returns: +ERROR:0006:~: - Calibration Jumper not inserted +ERROR:0007:~: - Error writing the data +ERROR:0009:~: - One of the parameters was invalid The system checks the validity of both TimeDate Structure:s before writing them to the...
  • Page 68 MEAS_SECX4 (0x02) - x4 Secondary Gain MEAS_SECX8 (0x03) - x8 Secondary Gain MEAS_SECX16 (0x04) - x16 Secondary Gain MEAS_SECX32 (0x05) - x32 Secondary Gain MEAS_SECX64 (0x06) - x64 Secondary Gain MEAS_SECX128 (0x07) - x128 Secondary Gain MEAS_SECX256 (0x08) - x256 Secondary Gain MEAS_SECX512 (0x09) - x512 Secondary Gain...
  • Page 69 MEAS_EN10V - 0x0A - Energize at 10V MEAS_EN40V - 0x28 - Energize at 40V MEAS_EN100V - 0x64 - Energize at 100V MEAS_EN10VCT - 0xFF - Energize at 10V for CT +OK:~: - The configuration and voltage were set successfully Returns: +ERROR:090A:~: - The voltage was invalid +ERROR:0911:~: - The specified configuration was bad The user should allow the system to stabilize before making any measurements.
  • Page 70 <Index> is the index number in the EEPROM to be read. This is one of: Fields: Pri. Volts. Range 1, Sec. Volts. Range 1 Pri. Volts. Range 1, Sec. Volts. Range 2 Pri. Volts. Range 1, Sec. Volts. Range 4 Pri.
  • Page 71 Fields: None +OK:~: - The dates and times were set successfully Returns: +ERROR:0006:~: - Calibration Jumper not inserted +ERROR:0007:~: - Error writing the data Comments: None Setup:ReadProcessedMeters This reads the calibrated meter readings from the system Structure: +S:P:~: Fields: None +OK: <Ratio>:<PriV>:<SecV>:<PriI>:<Freq>:<Phase>:<Status>:~: Returns: <Ratio>...
  • Page 72 Setup:Standard This sets the Standard for the system. +S:Z:<Standard>:~: Structure: <Standard> (Integer) sets the standard. It is one of the following Fields: 0 - Do not change standard, this allows the standard to be queried 1 - Set to ANSI standard. 2 - Set to IEC standard.

  • Page 73: Application Software Apsw 2796

    12.1 Application Software APSW 2796 The application software APSW 2796 allows remote operation of the Transformer Turns Ratio Meter TTR 2796. It simplifies the report handling and can be used to integrate the TTR measurements in a complete transformer test system.
  • Page 74 TTR 2796 connected displayed. Otherwise the message will appear. TTR 2796 not connected When the program is started in the simulation mode the status message will be shown. TTR 2796 simulated When the program can not communicate to the TTR although the instrument is connected to the computer most likely the wrong COM port was selected.

  • Page 75: Structure

    The functional descriptions of the title bar elements are: Device Name Name of the controlled device (TTR 2796). Document Name The actual active (loaded) test file and its path is shown here. All data are stored in this file.
  • Page 76 Status Message If the APSW 2796 is started in simulation mode the message “Simulation” appears in this field. If no TTR 2796 is connected but the program is started in the normal mode the message “TTR 2796 not connected” is shown.

  • Page 77: Tab Sheet Setup

    See section “Tab Sheet SETUP” for more details. Tab Sheet Measure This sheet contains alls necessary buttons and displays for remote controlling of the TTR 2796, such as TTR status indication, displaying of applied test, vector group configuration, etc. See section “Tab Sheet MEASURE” for more details.
  • Page 78 “Notes”. Menu Trafo Data Here the transformer winding system is defined and rated. Although the TTR 2796 detects automatically the vector group and phase displacement if known it will be manually entered in this menu.
  • Page 79 The following dialog pops up when clicking “Tap Parameters”: The Tap parameters can be entered here in the same way as in the firmware of the instrument itself. Application Software APSW 2796...

  • Page 80: Menu Options

    With the field “Activate” it can be selected if a defined tap shall be measured (yes) or not (no). If the tap voltages are evenly distributed they can be calculated automatic: By pressing the button the minimal and maximum tap voltage can be entered and the single tap voltages are evenly calculated and filled in the list. If the tap voltages are not evenly distributed the final values in the list can be edited by the user.
  • Page 81 Drop-down list “Temperature Unit” Here you can select the unit for temperature, if you choose “Celsius °C” the unit meter “m” will be automatically used for lengths. If “Fahrenheit °F” is selected the unit feet “ft” will be used. Drop-down list "Terms according" Currently three different conventions for phase labels are supported.
  • Page 82 Menu Auxiliary Here you can enter your own documentation fields. The title and field of each line can be free defined by the user. All titles and text field are also shown in the final printed document. Application Software APSW 2796...

  • Page 83: Tab Sheet Measure

    12.5 Tab Sheet MEASURE The tab sheet MEASURE is split into five parts. Display of Measurement Values At the top of the window the actual measurement values are displayed including vector group, test voltage, voltage ratio, ratio deviation and phase deviation. Control of Test Voltage and Tap Changer The editable elements in the middle section are used to specify the test voltage, the tap changer position and - if tertiary winding exists –...
  • Page 84 Display of Test Progress and Measurement Status A “Progress” bar shown at the left side under the voltage selection dialog indicates the actual test progress of the measurement. Beside the “Progress bar” a status message is displayed which reflects the actual state of the system. Following status messages appear: Status “System Ready”...

  • Page 85: Tab Sheet Analysis

    12.6 Tab Sheet ANALYSIS This sheet is intended for making post analysis in a graphical way. New measured data can be compared with older ones for trending purposes or simple threshold levels can be entered to specify PASS/FAIL criteria. Measured values can also be displayed against each other, for example to determine if the voltage ratio is linear with the tap changer position.

  • Page 86: More Analysis

    Button Save View Pressing this button will store the current view under the actual selected name. Button Show Actual Diagram Opens the actual diagram in program, which is associated with the file extension ‘.jpg’, where you can print it. The yellow, green and red area of the graphic can be set by clicking 12.6.1 More Analysis This tool is used to analyze several files at the same time.
  • Page 87 Button Remove All Pressing this button will remove all files from the list. Button Save List As Pressing this button will store the actual list in a file. Button Load List Pressing this button will load a list from a file. Button Show Analysis Pressing this button will open a dialog with all files from the list.

  • Page 88: Data Transfer

    12.7 Data transfer For transferring data from the TTR 2796 to the computer press button in the key bar at the bottom of the window. A dialog window will pop up where you can choose which measurements shall be uploaded to the computer.

  • Page 89: Arbitrary Phase Shift

    In the Tettex TTR 2796, arbitrary phase shift (APS) measurement is achieved by using a single-phase supply and with no extra hardware as elaborated earlier. The necessary three phase equivalent voltages at different transformer terminals are simulated by energising a pair of the transformer terminals and interconnecting certain other terminals using a custom approach.
  • Page 90 Once this option is selected a small window pops-up and prompts the user to give-in the activation code. Obtain the activation code from Tettex-Haefely Test AG. Once the correct activation code is given, a message pops up (see image below) confirming that arbitrary phase shift module is activated.
  • Page 91 To continue with the arbitrary phase shift measurements, following information should be known. (a) Type of the transformer to be tested. Transformer having at least two three phase windings Transformer having at least one winding in three phase and one winding in single-phase. (b) Primary and secondary winding configuration of the transformer.
  • Page 92 The remaining steps to turns ratio and phase shift measurement are as detailed earlier in section 12.5. The resulting display is as follows (for vector group Dd0.75) For the case of a transformer having at least one winding in three-phase and one winding in single-phase, with the primary side winding of the transformer configured as delta, the vector group settings on the primary and secondary should be set-up as shown in the image below.
  • Page 93 The remaining steps to turns ratio and phase shift measurement are as detailed earlier in section 12.5. Application Software APSW 2796...

  • Page 94: Accessories

    13 Accessories 13.1 Accessories 13.2 Verification Box 2796V The Verification Box is used to check the correct functionality of the Ratio Meter and its connected test cables. Different ratios (1, 10, 100, 1000) can be selected by the selector knob on top. Test cables have to be connected following the description on the front respectively the color code.

  • Page 95: Miscellaneous

    14.2 Care and Maintenance The TTR 2796 instrument is basically service free, as long as the specified environmental conditions are adhered to. As a result, service and maintenance is restricted to cleaning of the equipment and calibration at intervals stipulated by the application for which the instrument is used.

  • Page 96: Packing And Transport

    14.6 Customer Support All error messages appear on the display of the TTR 2796 measuring instrument. If persistent problems or faulty operation should occur then please contact the Customer Support Department of HAEFELY TEST AG or your local agent.

  • Page 97: Conformity

    14.7 Conformity Miscellaneous...

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