Megger MWA300 Series Instruction Manual
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Megger MWA300 Series Instruction Manual

Three-phase ratio & winding resistance transformer test set
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MWA300-UG-EN-V2
November 2016
Instruction Manual
for
Three-Phase Ratio & Winding Resistance
Transformer Test Set
MWA300 series
Catalog Numbers. MWA300, MWA300-47
HIGH-VOLTAGE EQUIPMENT
Read this entire manual before operating equipment
Valley Forge Corporate Center
2621 Van Buren Avenue
Norristown, PA 19403-2329
U.S.A.
610-676-8500
www.megger.com

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  • Page 1 MWA300-UG-EN-V2 November 2016 Instruction Manual Three-Phase Ratio & Winding Resistance Transformer Test Set MWA300 series Catalog Numbers. MWA300, MWA300-47 HIGH-VOLTAGE EQUIPMENT Read this entire manual before operating equipment Valley Forge Corporate Center 2621 Van Buren Avenue Norristown, PA 19403-2329 U.S.A.
  • Page 3 Three-Phase Ratio & Winding Resistance Transformer Test Set MWA300 series...
  • Page 4 Specifications are subject to change without notice. WARRANTY Products supplied by Megger are warranted against defects in material and workmanship for a period of one year following shipment. Our liability is specifically limited to replacing or repairing, at our option, defective equipment.

  • Page 5: Table Of Contents

    Table of Contents 1 MWA300 Product Overview ..........................1   2 SAFETY ................................3 3 SPECIFICATIONS ............................. 5   Input Power ..............................5   Protective Devices (Fuses) ..........................5   Output AC Test Voltage and Current ......................5   Test Frequency ..............................
  • Page 6 LIST OF FIGURES   Figure 6-1 Setup for Testing Single-Phase Transformer (Vector Diagram 1P0) ........30   ..    Figure 6-2 Setup for Testing Single-Phase Autotransformer (Vector Diagram 1P0) ......30   ..    Figure 6-3 Setup for Testing Single-Phase, Type A (Straight Design) Step Voltage Regulator .... 31  ...
  • Page 7 Prior to operation, check for loosened hardware or damage incurred during transit. If these conditions are found, a safety hazard is likely, DO NOT attempt to operate equipment. Please contact Megger as soon as possible. MWA300 Transformer Ratio & Winding Resistance Test Set...
  • Page 8 MWA300-UG-EN-V2 Nov 2016...

  • Page 9: Mwa300 Product Overview

    MWA300 Product Overview The MWA300 test set is an automatic unit which is designed to be controlled via a computer running PowerDB Lite software. The test set measures the turns ratio, phase shift, excitation current and winding resistance of power, distribution, and instrument transformers.
  • Page 10 Top Panel Controls Figure 1-1 Top Panel Controls 1. Power input receptacle. ON/OFF switch, and Mains fuse holder. ON/OFF power switch and input power receptacle provides power to the test set. 2. H – Cable receptacle. Plug receptacle for connecting test leads to the high- voltage (H) winding of a transformer 3.

  • Page 11: Safety

    In the event of equipment malfunction, the unit should immediately be de-energized and returned to Megger for repair. The Safety precautions herein are not intended to replace your Company’s Safety Procedures. Refer to IEEE 510 - 1983, IEEE Recommended Practices for Safety in High-Voltage and High-Power Testing, for additional information.
  • Page 12  Personnel using heart pacemakers should obtain expert advice on the possible risks before operating this equipment or being close to the equipment during operation. Input Power Precautions This instrument operates from a single-phase, sine wave, power source. It has a three-wire power cord and requires a two-pole, three-terminal (live, neutral, and ground) type input source.

  • Page 13: Specifications

    SPECIFICATIONS Electrical Input Power Cat. No. MWA300: 120 V, ±10%, 60 Hz, ±2 Hz, 660 VA IEC 1010-1 installation category II Cat. No. MWA300-47: 230 V, ±10%, 50 Hz, ±2 Hz, 660 VA IEC 1010-1 installation category II Protective Devices (Fuses) Main Input Fuse : Qty 2: 6.3 amp, 250V, 5x20mm, SLO-BLO (120V Ceramic) Qty 2: 4.0 amp, 250V, 5x20mm, SLO-BLO (230V Ceramic)

  • Page 14: Loading Of Test Transformer

    Loading of Test Transformer Less than 0.2 VA Measuring Ranges Turn ratio: 80 V ac: 0.8 to 45,000, 5 digit resolution 40 V ac: 0.8 to 25,000, 5 digit resolution 8V ac: 0.8 to 8,000, 5 digit resolution Excitation Current: 0 to 500 mA, 3 digit resolution Phase Angle Deviation: ±...

  • Page 15: Dc Output Current (User Selectable Ranges)

    Specifications Measuring Time 8 to 37 seconds depending on mode of operation and type of transformer WINDING RESISTANCE SPECIFICATIONS DC Output Current (User selectable Ranges) 10 mA 100 mA 2.5 A 5.0 A 7.5 A 10 A Open Circuit Test Voltage 40 V dc Measurement Voltage 20 V dc...
  • Page 16 Display Via external PC (user supplied) Memory Storage Via external PC (user supplied) Communication Interface USB 2.0 Serial Safety/EMC/Vibration Conforms to the requirements of: IEC1010-1: 2010 CE ASTMD999.75 IEC 61326-1:2012* *At radiated frequencies 80MHz – 100MHz, performance may be deteriorated. Environmental Conditions Operating temperature range: 23 to 122 F (-5 to 50 C)

  • Page 17: Software Installation

    .pdf file. PowerDB Lite allows you to use a sub-set of the standard PowerDB forms that are appropriate for specific Megger instruments. Minimum Recommended System  Operating System: Windows XP or later ...
  • Page 18 Software Installation To install PowerDB Lite, load the PowerDB Lite CD (or USB) into your computer drive and follow the on-screen instructions. For latest version, please go to website www.powerDB.com/download and download latest Lite version available. The model is contained within the software and not obvious until Lite software is loaded.

  • Page 19: Getting Started

    Software Installation 3. Select Default Settings (Language and Units of Measure). 4. Install Shield Wizard will complete the installation of PowerDB Lite. Click Finish to close the installation program. General Testing Procedures Getting Started 1. To determine that the MWA hardware is operational, observe the following: Once all Safety precautions are taken, and all circuit connections are made, the user may safely turn the ON/OFF switch to the ON position and operate the test instrument as described herein.
  • Page 20 3. Select MWA from the Instrument Setup screen. It may be located in “Favorites” or “Transformer/Power Factor Test Sets” and can be relocated as desired. The MWA300 uses USB connection only. Once MWA is selected, the proper settings for USB are pre-selected, and no further changes should be required. PLEASE ALLOW SUFFICIENT TIME FOR DRIVERS TO LOAD WHEN CONNECTING TO MWA300 FIRST TIME.
  • Page 21 Typical issues encountered may relate to the drivers for MWA300, and may require re-installation of the software to re-load drivers properly. As well, allow sufficient time for drivers to properly load. Beyond this, please contact your local ASC or direct to VFsupport@megger.com. MWA300-UG-EN-V2 Nov 2016...
  • Page 22 MWA300-UG-EN-V2 Nov 2016...

  • Page 23: Three Phase Ttr & Winding Resistance Testing

    THREE PHASE TTR & WINDING RESISTANCE TESTING The following is a detailed description of operational aspects of MWA test forms, with 3Ɵ Turns & Winding Resistance form below used as a reference. All other MWA forms use common methods as described in the example below. Ɵ...

  • Page 24: Test Form Controls - General

    Test Form Controls - General Once a form is opened, all forms have a set of standard controls which are available across the top of the form as shown below. This allows common functions such as saving, deleting, opening results, together with functions as described below. New allows a different test form to be selected within the MWA -brings up selection list from Menu in 1.

  • Page 25: Form Settings

    Three Phase TTR& Winding Resistance Testing Form Settings: Diagram Number: relates to TTR/MTO function where each vector combination has a specific diagram number associated with it. ii. Standard: ANSI/IEC/AUS depending on national standard used iii. Phase Display: when testing ratio, accompanying phase result displayed as “Degrees or Minutes (60 Minutes = 1 Degree) iv.

  • Page 26: Tap Settings

    Tap Settings Override Calc. Voltages/Tap Labels: allows individual entry for each field. Typically used for custom transformers. Note: When checked, all fields in tables below remain empty until manually populated. ii. H & L Numbering: allows labeling to follow transformer nameplate convention.

  • Page 27: Resistance/Ratio Settings

    Three Phase TTR& Winding Resistance Testing Resistance/Ratio Settings Nameplate Recommended: DC Test Current is provided as a guide for test current limits for each winding. NOTE: for high ratio transformers, testing windings in series may not give timely or accurate results because of insufficient test current for secondary windings.

  • Page 28: Transformer Nameplate

    Transformer Nameplate. Vector Selection: Once form setting (above) selects proper standard, one depresses the vector and a pop up Vector Selector will appear, or ‘right click’ to select primary and secondary vector until it matches transformer nameplate. ii. Transformer Nameplate Voltages: (line to line only), in volts. iii.

  • Page 29: Transformer Test Conditions

    Three Phase TTR& Winding Resistance Testing Transformer Test Conditions Environmental (Weather) Test Conditions input ii. Oil/Winding Temperature: readings input from transformer temperature gauges and used for optional correction of results to normalized temperatures iii. Test Status: Once testing is complete, indicates condition of the asset under test.

  • Page 30: Ratio Test

    Ratio Test Test Setup: reflects input from Transformer Nameplate (5.) above and tap under test ii. Test Results for each phase iii. Retest A/B/C: Depressing will retest individual phase iv. Retest or Test Tap or Done: Retest a tap, terminates test, or allows continuation to test next tap.

  • Page 31: Winding Resistance Testing

    Three Phase TTR& Winding Resistance Testing Winding Resistance Testing Descriptions for the following testing methods described below involve 3 methods of performing testing. 1. An automated sequence is determined and test operates through each winding and tap as required – 2.

  • Page 32: Method 1 - Resistance Test Wizard

    Method 1 - Resistance Test Wizard - Resistance Test Wizard is designed to automate the winding resistance test, allowing the transformer nameplate input (Section 5) combined with operator selection of taps to complete a test sequence with minimal button presses. This wizard also allows testing of OLTC taps without discharge of test current during transition(between) of taps, making testing both more efficient (less time charging and discharging winding and less button pressing) as well as diagnostic by indication...

  • Page 33: Method 2 - Measuring Tap - All Phases Winding Resistance

    Three Phase TTR& Winding Resistance Testing Method 2 – Measuring Tap – All Phases Winding Resistance - Test #: depressing this button commences testing for a specific tap row (circled). Testing is conducted sequentially (up to 2 windings at once), ensuring optimization of magnetized core.

  • Page 34: Resistance Test Screen

    Resistance Test Screen Once a test sequence begins from Method 1-3 above, the following screen will appear: Test Setup: allows changes to test parameters, which can be seen in item iv above (and described in section iv. below). This button is 'greyed out' once testing begins or MTO instrument connection is not established.
  • Page 35 Basic Connections to MWA300 Connections should be made in the order as listed below. Ground. Use the Megger supplied Safety Ground Cable 15 ft (4.6 m) to connect the MWA300 Ground Lug Terminal directly to Local Station Earth ground. Input Power Source Ground. Input Power Source Ground Terminal should be less than 0.1 Ω...
  • Page 36 MWA300-UG-EN-V2 Nov 2016...

  • Page 37: Transformer Testing Applications - Ratio & Winding

    TRANSFORMER TESTING APPLICATIONS – RATIO & WINDING The setup and connection instructions included in Section 4 herein, pertaining to ratio, polarity, phase relation and winding resistance, assume that the transformer under test, connections, and terminal markings comply with the requirements of ANSI C57.12.70-2011 American National Standards Terminal Markings and Connections for Distribution and Power Transformers or IEC 60076-1 Test Procedures for Power Transformers.
  • Page 38 Single-Phase, Two-Winding Transformers –including Typical Pole Type transformers with Dual Secondary’s Perform the following setup procedure for single-phase, two-winding transformers: 1. Connect the heavy-duty clamps marked H1(1U) and H2(1V) & X1(2U) & X2 (2V) of the test lead to the corresponding (high-voltage & low-voltage windings) terminals of the transformer under test.
  • Page 39 Transformer Testing Applications– Ratio & Winding To test windings other than H1(1U) – H2 (1V) and X1(2U) – X2 (2V), ensure that the heavy-duty clamp marked H1(U1) is connected to the lower numbered terminal and H2(V1) to the higher numbered terminal of the high-voltage winding. Similarly, X1(2U) and X2(2V) should be connected to the low-voltage winding.
  • Page 40 Figure 6-4 Setup for Testing Single-Phase, Type B (Inverted Design) Step Voltage Regulator (Vector Diagram VREG) Figure 6-5 Showing connections to a Pole Type Transformer with 2 secondary windings. To test with PowerDB, requires choice of 1P0, with 2 taps, changing leads between tests. MWA300-UG-EN-V2 Nov 2016...
  • Page 41 Transformer Testing Applications– Ratio & Winding Three-Phase, Two-Winding Transformers Perform the following setup procedure for three-phase, two-winding transformers: 1. Connect the clamps marked H0(1N), H1(1U), H2(1V), and H3(1W) of the test lead to the corresponding (HV winding) terminals of the transformer under test. Refer to Table 6-2 for test lead markings.
  • Page 42 Figure 6-6 Shows a Typical Connection to a 2 Winding YNyn or ZigZag – 8 Terminal Transformer Figure 6-7 Shows a Typical Connection to a Delta Delta or Yy (no neutral) 6 terminal transformer. Note: Neutral leads can be removed during this testing. Three-Phase, Three-Winding Transformers This type of transformers has primary, secondary, and tertiary windings.
  • Page 43 Transformer Testing Applications– Ratio & Winding 1. With the ON/OFF Switch in the OFF position, make the circuit connections as described in Section 3.2. 2. Connect the H(1) and X(2) test cables to the respective H(1) and X(2) receptacles of the MWA300. 3.
  • Page 44 Most CTs can be tested with 8 V ac excitation voltage. For larger CTs which have high saturation voltage (Relaying CTs fall into this category) higher test voltage results in better ratio and phase accuracy versus nameplate. Test voltage is conditional to the saturation design of the CT under test.
  • Page 45 Transformer Testing Applications– Ratio & Winding Figure 6-8 Setup for Testing Unmounted Current Transformer (only X1-X2 winding resistance can be tested for CTs) Use vector diagram 1P0 Figure 6-9 Setup for Testing Taps on Multiple Tap CT (only low side (X) windings can be tested for resistance) Use vector diagram 1P0.
  • Page 46 Bushing Current Transformer (BCT) Mounted on Single-Phase, Two-Winding Transformer A turn-ratio and winding resistance test can be performed on a BCT after it has been mounted on a circuit breaker or power transformer entrance bushing. The test can be performed without removal of the BCT from the equipment. Proceed as follows: 1.
  • Page 47 Transformer Testing Applications– Ratio & Winding Bushing Current Transformer (BCT) Mounted on Three-Phase Transformers A turn-ratio test can be performed on all three BCTs using a single setup. Figure 6-11 shows the proper test connections when the BCTs are mounted on a typical delta winding and Figure 6-12 shows how when mounted on a typical wye winding.
  • Page 48 Figure 6-11 Setup for Testing BCT Mounted on Delta Winding on a Three-Phase Power Transformer (Shorting only required during Ratio Test) – Use diagram YNyn0 MWA300-UG-EN-V2 Nov 2016...
  • Page 49 Transformer Testing Applications– Ratio & Winding Figure 6-12 Setup for Testing BCT Mounted on Wye Winding of a Three-Phase Transformer (Shorting only required during ratio test) –Vector diagram YNyn0 MWA300-UG-EN-V2 Nov 2016...
  • Page 50 MWA300-UG-EN-V2 Nov 2016...

  • Page 51: Test & Results Files - Saving And Retrieving

    TEST & RESULTS FILES - SAVING AND RETRIEVING When testing, data management is a critical function required after testing. For efficiency, the ability to replicate testing within time intervals is important. The software provided, PowerDB, is able to meet most requirements for large and small companies.

  • Page 52: Retrieving Results/Test Files

    After initial results are saved with a file name as per above, all testing results continue to be saved as testing is conducted. In order to rename a test file (result) user has the option to save result under a different name, as a template or as a PDF (original test file remains unchanged).
  • Page 53 Test & Results Files - Saving and Retrieving Once MWA instrument is selected, user can open saved result to view results and/or to retest/append results, or use present form as a template (once settings are entered into form). MWA300-UG-EN-V2 Nov 2016...
  • Page 54 MWA300-UG-EN-V2 Nov 2016...

  • Page 55: Service

    (example NIST in the USA). As a result of this calibration procedure, each MWA test set may be NIST certified. To check the ratio portion calibration at a customer site or in the field, the Megger Calibration Standard Cat. No. 550055 or equivalent standard should be used.

  • Page 56: Ratio Portion - Self Check

    Ratio Portion – Self check To ensure that the test set is functioning properly prior to testing a transformer, one can use an accessory (Cat No. 2005-249) provided with the MWA unit. The 1:1 turns ratio & phase deviation can be validated as an approximate accuracy and functional CHECK.

  • Page 57: Error Messages

    Service Troubleshooting – Ratio Testing Error Messages Once testing ratio begins, error message may appear, indicating an abnormal operating test condition which may be caused by operator error (lead misconnection, improper instrument configuration etc), instrument malfunction and/or malfunctioning transformer. Verify the condition by taking a repeat measurement before attempting to take any corrective action.
  • Page 58 CHECK PHASE A (or B, or C) POLARITY This message shows that the H or X test leads are incorrectly connected or the test transformer connections or markings do not comply with the requirements of ANSI, IEC, or the Australian standard. The Troubleshooting Guide Table 6-1 is arranged to help you evaluate the reasons for the TTR portion malfunction.
  • Page 59 In the event service is required, contact your Megger representative for a product Return Authorization (RA) number and shipping instructions. Ship the product prepaid, insured and marked for the attention of the Megger Repair Department. Please indicate all pertinent information, including catalog number, serial number, and problem symptoms.
  • Page 60 MWA300-UG-EN-V2 Nov 2016...

  • Page 61: Ordering Information / Spare Parts

    PC 1:1 Test Jig (instrument self-test) 2005-249 Optional Accessories Universal lead sets, compatible with Megger MWA3XX Series products (up to 10 A DC max) 3-phase, 4-wire shielded test leads (H&X), complete with color coded universal Kelvin clamps 2008-30-KIT 3-Ø...
  • Page 62 Item Cat. No. 2008-113-30 3-Ø Universal, 9 m (30 ft) H 2008-114-30 3–Ø Universal, 9 m (30 ft) X 2008-113-60 3–Ø Universal, 18 m (60 ft) H 2008-114-60 3-Ø Universal, 18 m (60 ft) X 3-ø Universal, 30 m (100 ft), H 2008-113-100 3-ø...

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