Oberebenestrasse Bremgarten Switzerland Tel Fax

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1 Oberebenestrasse Bremgarten Switzerland Tel Fax Winding Resistance Meter - 50 Amp/2 Channel Model: WR50-12 Instruction manual 1.01 WR50-12 preliminary

2 Table of Contents Section Page Table of Contents 2 Safety Precautions Uncrating Procedure Technical Specifications Introduction Advantages & Features 6 System Details Limitations of Testing 7 Discharging the Transformer windings 7 Front Panel Description Operation Getting started Archive The General Setup Menu Temperature measurements Option TP Temperature correction Setting the Clock Service Mode Basic Instructions Quick Test Trouble Shooting Error Messages Warranty Appendix A Update the Firmware 22 Appendix B License Key 23 Appendix C Heat Run Test (cooling curve) (Option) 25 RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 2

3 SAFETY PRECAUTIONS! 1-0 The following safety precautions must be observed during all phases of operation, service, and repair of this instrument. By purchasing this equipment the purchaser assumes all liability for the operation and use of this equipment. The intended use of the instrument, its design and manufacture, is to be conducted within the precautions or other specific warnings located within this manual. Failure to comply with these precautions and other specific warnings violates safety standards of design, manufacture, and intended use. Raytech Switzerland assumes no liability for the operation and use of this equipment. SAFE OPERATION Only qualified knowledgeable persons should be permitted or attempt to operate this test equipment. All test personnel should fully familiarize themselves with the correct application and operation of this and all test equipment prior to operation. Persons directly and indirectly engaged in the operation of this test equipment should keep clear of all high voltage apparatus while conducting tests and measurements. BEFORE APPLYING POWER Read this manual carefully before operating the system. The WR50-12 is line operated. The system operates from a wide range power input from 100 to 250 Vac 50/60Hz. DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes. KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers. Component replacement and internal repairs must be made by qualified service personnel. Do not replace components with power cable connected. To avoid injuries, always disconnect power, discharge circuits, and remove external voltage sources before touching components. DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards, do not install substitute parts or perform any unauthorized modification to the instrument. Return the instrument to a Raytech Switzerland service department for service to ensure proper operation and that safety features are maintained. Instruments, which appear damaged or defective, should be made inoperative and secured against unintended operation until qualified service personnel can repair them. TEST WARNING! Do not use on live circuits. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 3

4 UNCRATING PROCEDURE: 2 0 Unpack your new WR50-12 and check to see that you have the following standard items: WR50-12 Instrument Cable Set, consisting of: - Potential Leads 1. Channel - Potential Leads 2. Channel - Current Lead - - Jumper Lead - Current Lead + If any of the above items are missing or damaged contact your local representative or Raytech Switzerland immediately. The test leads may be ordered other than shown. * Note: The WR50-12 Field case is a waterproof design that incorporates an automatic pressure relief valve that will adjust to various atmospheric changes, i.e... Airplane Travel, High altitudes, etc... The valve is designed to be water resistant. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 4

5 TECHNICAL SPECIFICATIONS 3 0 MODEL: WR50-12 SIZE: L: 521 mm (20.5 ) W: 432 mm (17 ) H: 216 mm (8.5 ). WEIGHT: 16.6 kg (36.6 lbs.). INPUT POWER: 90 to 264 Vac (1.5kW max.), 50/60 Hz, Automatic ranging. OUTPUT VOLTAGE: 0 to 50V DC. TEST CURRENT: User Selectable: Ampere. PANEL DISPLAY: Color LCD with back lighting and touch screen. FRONT PANEL: Sealed anodized. INTERFACE: 9 Pin RS232 Serial / 2 USB 1.1 MEMORY STORAGE: Stores up to complete test results. RESISTANCE RANGE : 0.00 µω to kω MEASUREMENT PARAMETERS: Current Range Measuring Range Accuracy Resolution Amp 0.00 µω Ω ± 0.1% Rdg ± 0.05 µω 5 Digits or 0.05 µω Amp 0.0 µω Ω ± 0.1% Rdg ± 0.1 µω 5 Digits or 0.1 µω Amp 0.0 µω Ω ± 0.1% Rdg ± 0.2 µω 5 Digits or 0.2 µω Amp 0.0 µω Ω ± 0.1% Rdg ± 0.5 µω 5 Digits or 0.5 µω Amp 0.0 µω Ω ± 0.1% Rdg ± 1 µω 5 Digits or 1 µω Amp mω Ω ± 0.1% Rdg ± 2 µω 5 Digits or 2 µω Amp mω Ω ± 0.1% Rdg ± 5 µω 5 Digits or 5 µω Amp 0.00 mω Ω ± 0.1% Rdg ± 10 µω 5 Digits or 10 µω mamp 0.00 mω Ω ± 0.1% Rdg ± 20 µω 5 Digits or 20 µω mamp 0.00 mω kω ± 0.1% Rdg ± 50 µω 5 Digits or 50 µω mamp Ω... 5 kω ± 0.1% Rdg ± 100 µω 5 Digits or 100 µω - 10 mamp 5 kω kω ± 0.1% Rdg ± 1 Ω 5 Digits or 1 Ω - 10 mamp 10 kω kω ± 0.8% Rdg ± 20 Ω 5 Digits or 20 Ω TEMPERATURE : Operating: -10 C to 60 C Storage: -20 C to 70 C CABLE SET / ACCESSORIES Current and potential lead set 10 meters, Jumper cabel, Instruction Manual. FEATURES: Standard Items Charges inductive loads up to 1500 Henry Heavy-duty protection circuitry Simple touch screen operation Data exchange with an USB-Key 3 Temperature channels High power DC Supply ( 50A/50V ) DC Current adjustable for resistance values from 0.0 µω to 100 kω Fastest Discharge unit on market ( more then 10 times faster ) Discharge Indicator visible and audible indicator for discharge status Demagnetizing Circuit (world unique) Warning device output to show transformer under test Emergency stop push button immediately turns off power and starts discharging Data transfer to internal Printer Data Storage of up to measurements Mounted in rugged case for field-testing. 2 Year standard warranty OPTIONS: Part No - TP 01 External Temperature probe assembly Part No - AHRT 01 Heat Run Test * Specifications are subject to change at anytime. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 5

6 INTRODUCTION 4-0 Raytech Digital Winding Resistance meter WR50-12 is the successor of the very successful type WR50-2. It is the improved type with the world unique demagnetizing circuit. It is designed for high degree of accuracy for the measurement of very low resistance of inductive loads. This technology was then packed into a portable test system for use by apparatus manufacturers, rebuild shops, and electrical maintenance crews. Ease of use: This intelligent system has an easy to use operation screen, which allows quick selection of the current level to be measured. Just point with your finger on the item you want to change or activate. Impressive Accuracy: The WR50-12 is a high precision, fully automatic, multi-microprocessor based system. This system is designed for highly accurate readings on-site with laboratory precision. Unique Measuring Technique: This newly designed technique of measurement incorporates a high precision measurement circuit, a unique power source and the fastest discharge unit on market. Extensive filtering and high precision standards are used within the test system. The system is capable of precision measurements to 50 A. Operation: The WR50-12 applies a preset current level, selected by the User. The 50V power source quickly charges the load and the results of the test are displayed within a few seconds automatically. The results are reported on the easy to read color LC display and can be stored or printed. Compact Design: The WR50-12 is one of the most lightweight systems available that comes complete with its own rugged waterproof Fieldcase. Simple Maintenance: There is No maintenance required. There is No calibration procedure (No potentiometers to turn). This is due to the utilization of high precision components in the design. Advanced Protection: Upon powering on the system initializes itself with a self-calibrating, circuit checking sequence. If any problems are detected during this initialization period, or during operation, the operator is immediately notified. The system constantly monitors the condition when turned on. The WR50-12 has extensive protection built in to the circuitry. This is one of the many reasons we can extend our warranty to 2 years. Advantages & Features: Highest accuracy and Precision of any high current test system. Automatic measurements of Low Resistance from 0.1µΩ...10kΩ. Demagnetising Circuit (world unique) Microprocessor based system with internal storage for over test results. Printing and Storage of test results while the test system is measuring. Complete automatic calibration system and system diagnostics. Standard USB 1.1 & RS232 (serial) Interface. Pure filtered DC Power source for the highest accuracy readings. Automatic, high efficiency cooling system to dissipate internal temperatures. Automatic shut off for over-temperature condition Panel mounted Emergency Stop Switch Wide input power source range Lightweight and Portable, less than 16.6 kg (36,6 Lbs.) 2 Year standard warranty RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 6

7 SYSTEM DETAILS: 5-0 System Check: The instrument is Line operated. The system is designed to be used with voltage power sources (mains power) between Vac 50/60Hz. The system performs a self-check each time that it is powered on. The User should always visually inspect all connectors, cables and devices to be measured to avoid any safety issues. Limitations of Winding Resistance Testing: In general, there are no limitations on testing low or high inductive windings of transformers. The test system is specially designed to test all transformer windings. Discharging the Transformer windings: The WR50 systems are specialized systems designed to measure Transformer windings. These systems are equipped with heavy-duty discharge circuits that are very unique in the market! The internal discharge circuit dissipates the stored energy in the transformer windings with Constant Power Discharge Circuit that is unique to all transformer winding test systems. That is the reason why Raytech systems can discharge transformers more then 10 times faster then any other system on the market. If a cable happens to fall off during test, the system will STILL discharge the test object safely with the automatic Constant Power Discharge Circuit. The Potential Test Leads are part of the safety circuit and require the ability to discharge a transformer in the case where a current lead may become detached. DO NOT USE A SMALLER GAUGE POTENTIAL CABLES THEN THE ORIGINAL RAYTECH CABLES SUPPLIED! Low Resistance Testing: The WR50-12 utilizes a 4 wire measuring technique on each Channel. The points where the potential leads are connected determine the resistance reading. The test set employs a very simple principle of Ohm s law: R=U/I R = Resistance, U = Voltage, I = Current RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 7

8 FRONT PANEL DESCRIPTION: 6-0 Power Emergency OFF Power cord connection Press to stop On/Off switch Turn Clockwise Accepts V AC to release 50/60 Hz Interfaces: USB 1.1 USB 1.1 Serial RS232 Bi-directional Host Device Female 9 pin connector RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 8

9 FRONT PANEL DESCRIPTION: (cont.) 6 0 Test Connections: +Current = Positive Current connection +Channel 1= Positive Potential (voltage) connection of Channel 1 -Channel 1= Negative Potential (voltage) connection of Channel 1 +Channel 2= Positive Potential (voltage) connection of Channel 2 -Channel 2= Negative Potential (voltage) connection of Channel 2 -Current = Negative Current connection Temperature Probe connection: External Flashlight: Three 2 pin Connections for optional external temperature probes ( TP 01 ) Connection for an external Flash Light or Beeper to indicate a Dangerous condition. Working contact Pin (230Vac 2A) Danger condition Display: Shows that Current is flowing. Shows that you bought Shows that test Object is Don t remove any Cable! the right Instrument. in Safe condition. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 9

10 OPERATION: 7-0 WARNINGS! BEFORE OPERATING THIS OR ANY OTHER TEST EQUIPMENT READ ALL SAFETY WARNINGS AND UNDERSTAND THEM FULLY. OPERATION: This section describes a typical, step-by-step, operation of the WR50-12 Open the protection lid of the case and attach the test leads and the power cord to the test set. The Two (2) connections on the front plate +Current & -Current are the current leads. The Four (4) connections on the front plate +Channel 1 & -Channel 1 and +Channel 2 & -Channel 2 are the Potential or Voltage leads. By connecting a test specimen to the Current leads and applying the potential leads across the specimen the resistance readings will be determined. GETTING STARTED: 7-1 Turn the Power switch, located at the power input connector to the I position. The Initial screen will appear During this Time, the Instrument is performing the initial calibration. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 10

11 GETTING STARTED: (cont.) 7-1 When everything is ok, the main screen will appear: The WR50-12 incorporates a touch-screen display for all input parameters. Select the current range to measure by touching the word Range. The following screen appears: Now you may select the current you want to choose by tapping on that range ( p.e. 10 A ). There are 3 buttons to set a user selectable current, adjust the current by pressing Set After selection of the required range, start the measurement by just touching the Start Button. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 11

12 At the start of a test a single audible beep will be heard as a reminder that the test system is about to charge the inductive windings. Operators should be careful not to remove any cables while the test system is measuring. During the measurement you will see the following: The operator may press Store at anytime to store a complete record. The current continues to flow and the system will measure until touching Stop halts the Measurement. DO NOT TOUCH, MOVE OR MANIPULATE THE MEASURING CABLES BEFORE YOU HEAR TWO BEEPS AND THE DISPLAY AND LAMPS SHOW A SAFE CONDITION! RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 12

13 ARCHIVE: 7-2 To access the Archive (Memory locations), touch Results on the screen and then Show on the next screen. Remember: Not all menus are active during the measuring process. The Headers column displays the listed stored results. Saving multiple results during the measuring process stores the data under one header location. All the stored results linked to a particular header are accessible by touching Details By touching the arrows on the bottom left or right, you will see all the stored results of that selected measurement. An empty field (p.e. T1) indicates that no temperature probe was plugged into connector Temp 1 on the front panel. The column Time is the time that has past after starting the measurement process. By touching one of the Menus in the Menu-bar you have the following options: Print Printing selected Measurement Printing ALL the Measurements Clear Erase selected Measurement Erase ALL Measurements Export Store the results to an USB-Device (p.e. USB Key) RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 13

14 THE GENERAL SETUP MENU: 8-0 To access the Setup Menu, select (touch) Setup and then General Service Mode Not for public use. See chapter 12.0 Firmware Update To update or change the built in Firmware See Appendix A About Check the version of the installed Firmware. See Appendix A Clock Settings Setting the clock. See chapter 11.0 Show Mouse Cursor Show or hide the Mouse Cursor. Usefully if you operate with a mouse at USB If you touch R1 or R2, the following screen appears Now you can enter any Name for R1 and R2 you want. If you are done, press Hide RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 14

15 TEMPERATURE MEASUREMENTS: 9-0 The system allows up to Three (3) temperature probes to be used with the system for the purpose of recording temperatures. Optional Part Number: TP 01, can be purchased for this purpose. Recording the temperature of the device under test is highly recommended due to the characteristics of the increase of resistance of a metallic object as its temperature increases. There are temperature compensation tables for Copper and Aluminum available to calculate the conversion factor to a known reference temperature. The WR50-12 is a very accurate and precise test system. To take full advantage of this high accuracy, the temperature of the device under test should be recorded. The TP 01 temperature probe is mounted to a flexible extension cable that plugs into the front panel of the WR This option enables the User to record the ambient temperature and/or the actual temperature of the device under test. The WR50-12 will automatically sense when the optional temperature probes, TP 01, are connected to it. The temperature will be displayed on the instrument screen during a test and will appear when a printed report is requested. The temperature, as well as the test results, can be saved into memory. TEMPERATURE CORRECTION: 10-0 The WR50-12 can, fully automatic, correct the measured values regarding the temperature. To activate this feature press Setup and then Temp. Correction In this example, the measured object is copper and will be corrected to 25Degrees Celsius based on the temperature on Temperature channel 1. If you do not have a Raytech Temperature probe, activate the Ext box and fill in the temperature you measure with your other temperature probe. The correction follows the formula: Rs=Rm[(Ts+Tk)/(Tm+Tk)] where Rs is resistance at desired temperature, Ts Rm is measured resistance Ts is desired reference temperature Tm is the temperature at which resistance was/is measured Tk is for copper, 225 for aluminum (aluminum may be as high as 240) If you are used to a correction with alpha25 you can calculate the Tk by the formula: Tk=(1/alpha25)-25 RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 15

16 TEMPERATURE CORRECTION: (cont.) 10-0 If you are using another Tk then the standards for cooper or aluminum, activate the box User defined and input the Tk in the box below. When Temperature correction is activated, the main screen looks as follows: The T in the box at each measuring channel shows that the displayed resistance value is corrected (in this example to 25Degrees using Tk of cooper and referring to Temperature probe 1). In case the T in the box is red, ther is no temperature probe connected. If you want to see the real (not corrected) value, just hit the T and it looks like follows: The crossed T shows that the displayed resistance value is NOT corrected. No matter if you activate the correction in the display or not, the corrected AND the uncorrected values are stored. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 16

17 SETTING THE CLOCK: 11-0 To set the clock, go to the main screen and select (touch) the Setup and then the Clock Settings Set the desired values by touching the Up or Down arrows next to the related locations. By selecting (Touching) Set the Clock will be activated and set. SERVICE MODE 12-0 In the Setup Menu is a Service Mode. This Mode is for internal service use only and not accessible. A login code is required. Touch # to Exit. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 17

18 BASIC INSTRUCTION: 13-0 WARNINGS! BEFORE OPERATING THIS OR ANY OTHER TEST EQUIPMENT READ ALL SAFETY WARNINGS AND UNDERSTAND THEM FULLY. WARNINGS! BEFORE USING THE BASIC OPERATING INSTRUCTIONS THE OPERATOR SHOULD BE COMPLETELY FAMILIAR WITH THE TEST SYSTEM AND THIS TYPE OF TESTING. QUICK TEST: 13-1 This section outlines the basic measurement instruction, step by step, for the WR These are basic instructions, simplified, for the trained and qualified operator. 1. Connect the test leads (2 Current / 2 or 4 Potential) to an un-energized device to be measured. 2. Connect the Safety Ground on the front panel to known good Earth Ground. 3. Turn on the system. 4. Touch Range. 5. Select the Current Range. 6. Select (Touch) Start to start the test. 7. When results are displayed and are stable press Store. 8. To end the test press Stop. 9. Wait for Safe Status display RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 18

19 Troubleshooting GENERAL 14 0 At powering on, the WR50-12 internal calibration and check sequence is performed. Upon completion of the check sequence the test set will proceed to the Main Screen. Should there be any problem with the test set an error message will appear. SYSTEM DOES NOT DISPLAY ANYTHING: 1. Check the display for any Initialization. 2. Check the fuse. The fuse is located in the Power switch / plug connector. SYSTEM POWERS ON BUT THE DISPLAY FADES OUT OR BLINKS: 1. Check the input power line for faults. 2. If an extension cord is being used, check the size and condition of. An extension cord should not exceed 25 feet long and should be at least #12 wire minimum. TEST CURRENT CANNOT BE TURNED ON. 1. Is the Emergency stop switch pushed in? Turn to release it. 2. Is the system connected in an excessive interference area? ERRATIC OR ERRONEOUS READINGS Possible causes 1. Test lead damaged or not connected. 2. Poor test lead connection. 3. Poor supply power. Check extension cords, plugs cables carefully. 4. Test set attached to a Live load or high interference load. The WR50-12 is designed to be trouble free. If problems or questions do arise please contact your nearest Dealer or our service support group in Switzerland. Office Tel , Office Fax RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 19

20 ERROR MESSAGES 15 0 The emergency switch is activated In this condition it is impossible to start a measurement. Exiting this message screen by touching OK without releasing the emergency switch, The system will revert to a pretest or main screen similar to the following screen: Because the emergency switch is still depressed, you are not able to start a new measurement. All other features of the system ( storing, printing ) are still active Attempt to store results to the USB-key without any device key plugged to the WR50-12 Plug the USB-key in and try again. The following will appear: RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 20

21 WARRANTY RAYTECH Switzerland shall at their option and expense, repair, replace or newly provide any parts or services that prove to be defective within the warranty limitation periodirrespective of the operating time of the test equipment provided that the cause of the defect occurred prior to the time at which the risk was passed. 2. Warranty claims are subject to a warranty limitation period of 24 months from the date of shipment. 3. The purchaser is obligated to immediately notify RAYTECH Switzerland in writing form of any defects of the supplied test equipment. 4. RAYTECH Switzerland must always be given the opportunity to rectify a defect within a reasonable time. The purchaser shall grant an adequate time within the test equipment shall be repaired. 5. RAYTECH Switzerland covers the costs associated with the repair of the defect. Especially the costs for the material and work. Cost for sending the faulty test equipment shall be borne by the purchaser. RAYTECH Switzerland shall not be liable for material damage, or financial loss due to the loss of production, loss of data, loss of information, data or interest, regardless of their legal basis. 6. Warranty claim rights on replacement parts as well as repair of defective parts shall expire after 12 months. 7. Warranty limitation period shall be extendable according to the price list. The purchaser has the right to extend the warranty period by purchasing additional warranty years. Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper and unauthorized modifications or misuse and abuse of the product, negligence, alteration, modification, faulty installation by the customer, customer s agents or employees. Attempted or actual dismantling, disassembling, service or repair by any person, firm, or corporation not specifically authorized in writing by Raytech Switzerland. Defects caused by or due to handling by carrier, or incurred during shipment, trans-shipment, or other move. Inadequate maintenance by the customer, second source supplied software or interfacing, operation outside the environmental limits, or improper site preparation. Exclusive remedies provided herein are the customer s sole and exclusive remedies. Raytech Switzerland shall not be liable for any damages resulting from the use of this equipment whether direct, indirect, special, incidental, or consequential damages, or whether based on contract, tort, or any other legal theory. NO OTHER WARRANTY IS EXPRESSED OR IMPLIED. Arbitration 1. All disputes arising out of or in connection with the contract between the purchaser and RAYTECH Switzerland and including those regarding the legal validity of this contract and this arbitration clause shall be settled out of court and shall be referred to arbitration for final decision. 2. Any disputes between the purchaser and RAYTECH Switzerland shall be settled according to the rules of settlement and arbitration of the chamber of commerce in Zurich by one or more arbitrators appointed also according to the rules of arbitration of the chamber of commerce in Zurich Switzerland. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 21

22 APPENDIX A UPDATE THE FIRMWARE: You can easily check the Firmware Version installed on your WR In the Main Display touch Setup - and then the About key A newer Version may be available and can be found at this link: Download this new version and store it to the USB Key. Switch the WR50-12 on and plug the USB Key into the USB Port of the Instrument. Press Setup and then Firmware Update : Select the Version you want to install and then press Install The only thing you have to do now is to wait until the system reboots. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 22

23 APPENDIX B LICENSE KEY Checking State of Licenses Press License Manager In the License Manager the Status of the Licenses can be checked. Press Enter New Licenses Key for entering a new License. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 23

24 Enter the License in the format xxx.xxx.xxxx and press Check The Licensekey is valid only for a specific WR50. Renting licenses can be entered only ones. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 24

25 APPENDIX C WR50 - Heat Run Test (cooling curve) Setup Activate Interval Mode and select the interval time ( time in sec between measuring points) and the number of data points. Deactivate Temperature correction RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 25

26 Start of the pre-measurement timer During the heat run test the transformer was heated up by an external power source. At the moment of the switching off the power source, the heat run timer has to be started. Press Timer Button on the main screen. The timer is now running The timer can be stopped by pressing the button a second time. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 26

27 Measurement is started by pressing the Start -Button. Starting Measurement After charging the transformer, the systems waits until the results are stable. Then results are stored automatically. After storing the last measurement the WR50 is stopped and the transformer is discharged. With the Stop -Button the measurement can be interrupted. After stopping the measurement, the timer is not stopped. Further measurements (other windings on the same transformer) can be made. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 27

28 Analyzing the HRT results. Select the Data-set in Result Screen Press Detail -Tab to see all stored results. Select in the menu HRT / Analyze The graph of the measured values is shown. Press Analyze You ll be asked for Approximation Model to calculate the Value of the Winding at time = 0. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 28

29 Select the Approximation Model (Exp)onential or (Lin)ear After setting the Model press Analyze The value of the approximation R(t=0) is shown. Meaning of the Parameters When Linear Approximation was selected R0: Value of the Windingresistance at time t= 0 m: devation dr/dt in %/ min Cor: Correlation of the approximation RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 29

30 When Exp Approximation was selected R0: Value of the Winding resistance at time t= 0 tau: time constant R : Value of the Winding resistance at time t Cor: Correlation of the approximation The approximation and the measured values Showing the graph in C When the resistance of the Winding and the material is known, all the values can be expressed as C. Enter the Value of the Winding at reference temperature and the temperature coefficient of the conductor. Values shown as Temperature. RAYTECH Switzerland All rights reserved. No portion may be reproduced without written consent 30