doble Vanguard Instruments WRM-10P S2 User manual

WRM-10P S2
TRANSFORMER WINDING RESISTANCE METER
USER’S MANUAL
1520 S Hellman Avenue, Ontario, CA 91761
TEL: [phone] | FAX: [phone]
www.vanguard-instruments.com
October, 2017
Revision 1.0

WRM-10P S2 USER’S MANUAL REV 1.0
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SAFETY SUMMARY
FOLLOW EXACT OPERATING PROCEDURES
Any deviation from the procedures described in this operator’s manual may create one or more safety hazards,
damage the WRM-10P S2, or cause errors in the test results. Vanguard Instruments assumes no liability for unsafe
or improper use of the WRM-10P S2. The following safety precautions must be observed during all phases of test
set up, test hookups, testing, and test-lead disconnects.
SAFETY WARNINGS AND CAUTIONS
This device must be used only by trained operators. All transformers under test must be off line and fully isolated.
SERVICE AND REPAIR
•Do not install substitute parts or perform any unauthorized modification to any WRM-10P S2 test unit.
•Repairs must be performed only by Vanguard Instruments factory personnel or by an authorized repair service
provider. Unauthorized modifications can cause safety hazards and will void the manufacturer’s warranty.
EQUIPMENT RATINGS
IP Rating: The enclosure for the WRM-10P S2 has an IP rating of 32.
Pollution Rating:The WRM-10P S2 has a pollution rating of 2.
Operating Voltage: The WRM-10P S2 is rated for use with an operating voltage of 120V or 240V, auto-ranging
±10% of selected voltage.
Power Cord: The WRM-10P S2 is supplied with a 16 AWG, 16A power cord with a NEMA 5-15P plug. Replacement
cable must have the same or better rating and is available through the manufacturer.
VENTILATION REQUIREMENTS
The WRM-10P S2 must be operated with the enclosure lid open.
SAFETY SYMBOLS
Indicates that caution should be exercised
OR
Indicates loca
tion of chassis ground terminal
CLEANING
To clean the WRM-10P S2:
•Disconnect all cables and turn the unit off.
•Use a soft, lint-free cloth to wipe all surfaces clean.
•Avoid getting moisture in openings and connectors.
•DO NOT use any cleaning products or compressed air

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TABLE OF CONTENTS
CONVENTIONS USED IN THIS DOCUMENT ..................................................................................... 1
1.0 INTRODUCTION.................................................................................................................... 2
1.1 General Description and Features ................................................................................... 2
1.2 WRM-10P S2 Technical Specifications............................................................................. 4
1.3 WRM-10P S2 Controls and Indicators.............................................................................. 5
2.0 PRE-TEST SETUP ................................................................................................................... 6
2.1 Operating Voltages .......................................................................................................... 6
2.2 LCD Screen Contrast Control............................................................................................ 6
2.3 Printer Paper Control....................................................................................................... 6
2.4 Printer Paper.................................................................................................................... 6
2.5 Replacing the Thermal Printer Paper............................................................................... 7
3.0 OPERATING PROCEDURES ................................................................................................... 8
3.1 WRM Cable Connections ................................................................................................. 8
3.2 General Procedures ....................................................................................................... 10
3.3 Entering Test Record Header Information..................................................................... 11
3.4 Setting the Clock ............................................................................................................ 14
3.5 Toggling the Calibration Notification Feature ............................................................... 15
3.6 Performing a Resistance Test......................................................................................... 16
3.7 Performing a Load Tap Changer / Voltage Regulator Resistance Test.......................... 25
3.8 Performing a Special Resistance Test ............................................................................ 32
3.9 Performing a Transient Test........................................................................................... 39
3.10 Performing a Diagnostic Test......................................................................................... 44
3.11 Working with Test Records ............................................................................................ 46
3.11.1. Restoring a Test Record from the Unit's Internal Flash EEPROM .......................... 46
3.11.2. Restoring a Test Record From a USB Flash Drive ................................................... 50
3.11.3. Viewing a Test Record ............................................................................................ 52
3.11.4. Printing a Test Record ............................................................................................ 54
3.11.5. Saving a Test Record From the Working Memory ................................................. 55
3.11.6. Copying Test Records to a USB Flash Drive............................................................ 57
3.11.7. Printing a Directory of Test Records Stored in the WRM's Internal Memory........ 59
3.11.8. Printing a Directory of Test Records Stored in a USB Flash Drive.......................... 62
3.11.9. Erasing Test Records From the Unit's Internal Memory........................................ 64
3.11.10. Erasing Test Records From a Connected USB Flash Drive...................................... 67
4.0 WRM-10P S2 SPECIAL FEATURES....................................................................................... 70
4.1 Bypassing the Resistance Reading Delay ....................................................................... 70
4.2 Converting Resistance Measurements .......................................................................... 71
5.0 Troubleshooting Guide ...................................................................................................... 72

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LIST OF FIGURES
Figure 1. WRM-10P S2 Controls and Indicators.............................................................................. 5
Figure 2. Typical WRM Connections Diagram #1............................................................................ 8
Figure 3. Typical WRM Connections Diagram #2............................................................................ 8
Figure 4. Typical WRM Connections Diagram #3............................................................................ 9
Figure 5. Typical WRM Connections Diagram #4............................................................................ 9
Figure 6. Typical V1 Test Report Printout ..................................................................................... 22
Figure 7. Typical V1 and V2 Test Report Printout......................................................................... 23
Figure 8. Typical V1 and V2 Test Report Printout with Multiple Readings .................................. 24
Figure 9. Typical LTC/Voltage Regulator Test Report Printout..................................................... 31
Figure 10. Typical Special Test Report Printout (1 minute @ 10 second intervals) ..................... 38
Figure 11. Typical Transient Test Report ...................................................................................... 43
Figure 12. Typical Internal Test Record Directory Printout .......................................................... 61
Figure 13. Typical USB Flash Drive Test Record Directory Printout.............................................. 63
LIST OF TABLES
Table 1. WRM-10P S2 Technical Specifications .............................................................................. 4

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CONVENTIONS USED IN THIS DOCUMENT
This document uses the following conventions:
•The WRM-10P S2 is referred to as WRM for short.
•A key, switch, or knob on the WRM-10P S2 is indicated as [KEY],[SWITCH],[KNOB].
•Menu names are referenced as “MENU NAME”
•WRM LCD screen output is shown as:
•Warning messages are indicated as:
WARNING
Warning message
•Important notes are indicated as:
NOTE
Note details
1.OPTION 1
2.OPTION 2
3.OPTION 3
4.OPTION 4





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1.0 INTRODUCTION
1.1 General Description and Features
The WRM-10P S2 is Vanguard's second generation lightweight winding resistance meter,
designed to accurately measure the winding resistance of highly inductive power transformers.
The unit’s dual resistance-reading input channels can measure two winding resistances
simultaneously, and four-wire (Kelvin) connections provide high accuracy and require no lead
compensation. The WRM-10P S2 provides stable resistance readings of very large transformers
by utilizing a 36Vdc power supply capable of outputting up to 10 Amperes. The resistance
reading of a 100MVA transformer can be achieved in 5 minutes or less. The unit’s power supply
is cooled by heavy-duty fans designed for continuous operation. For greater flexibility in the
field, the WRM-10P S2 comes with a built-in 2.5" wide thermal printer used for printing test
reports.
The WRM-10P S2 can also be used to measure EHV circuit-breaker contact resistance, motor
winding resistance, or any low resistance since it can accurately measure resistances ranging
from 1 micro-ohm to 2,000 ohms. If the transformer winding temperature is entered, the
WRM-10P S2 can calculate the equivalent resistance value of the winding material (aluminum
or copper) at any standard reference temperature. Also, a special test mode can run a test for
up to 60 minutes while saving resistance readings at 10, 15, 20, 30, or 60 second intervals. In
addition to measuring the resistance value, the WRM-10P S2 also checks the “make-before-
break” tap-switching sequences of voltage regulators and load tap changers.
The WRM-10P S2 is furnished with three 50-foot test cables. Each test cable lead is terminated
with a quick-disconnect test clip.
Built-in Safety Features
The WRM-10P S2 automatically dissipates the stored energy in the transformer at the end of
each test. This discharge circuit will continue to work even if the supply voltage is lost. For
added safety, the unit’s power supply is thermally protected from over-load damage.
User Interface
The WRM-10P S2 features a 5" back-lit LCD screen (240 x 128 pixels) that is viewable in bright
sunlight and low-light levels. A rugged, "QWERTY"-style, membrane keyboard is used to control
the unit.
Built-in Thermal Printer
The WRM-10P S2 features a built-in 2.5” wide thermal printer that can be used to print test
reports in the field.

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Internal Test Record Storage
The WRM-10P S2 can store 100 test records (up to 64 readings per test record) in Flash
EEPROM. Test records can be retrieved and printed on the built-in thermal printer or can be
transferred to a PC via the USB PC or USB Flash drive interfaces. Windows® -based software is
provided with each WRM-10P S2 that can be used to retrieve test records from the unit and can
also be used to export records in Microsoft® Excel format.

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1.2 WRM-10P S2 Technical Specifications
Table 1. WRM-10P S2 Technical Specifications
TYPE
Portable transformer winding resistance meter
PHYSICAL SPECIFICATIONS
Dimensions: 17.5”W x 11.75”H x 12.5” D (44.5 cm x 29.8 cm x 31.8 cm)
Weight: 27 lbs (12.2 kg)
INPUT POWER
100 – 120 Vac or 200 – 240 Vac (factory pre-set), 50/60 Hz
RESISTANCE READING
RANGE
1 micro-ohm –2,000 ohms
ACCURACY
1 – 19,999 micro-ohms: ±0.5% reading, ±1 count
20 – 999 milliohms: ±1% reading, ±1 count
1 – 2,000 ohms: ±1.5% reading, ±1 count
TEST VOLTAGE
36 Vdc max
TEST CURRENT RANGE
Auto range, 10 Amperes max
DISPLAY
5" back-lit LCD screen (240 x 128 pixels); viewable in bright sunlight and low-
light levels
PRINTER
2.5-inch wide built-in thermal printer
KEYPAD
Rugged "QWERTY"-style membrane keypad
INTERNAL TEST RECORD
STORAGE
Stores 100 test records of 64 readings each
COMPUTER INTERFACE
USB PC, USB Flash drive
PC SOFTWARE
Windows®-based software is included with purchase price
SAFETY
Designed to meet IEC61010 (1995), UL61010A-1, CSA-C22.2 standards
TEMPERATURE
Operating: -10˚C to +50˚ C (+15˚F to +122˚ F)
Storage: -30˚ C to +70˚ C (-22˚F to +158˚ F)
HUMIDITY
90% RH @ 40°C (104°F), non-condensing
ALTITUDE
2,000 m (6,562 ft) to full safety specifications
CABLES
Three 50-foot (15.24m) test cables, one ground cable, one power cord, one
USB cable and cable carrying bag
OPTIONS
Shipping Case
WARRANTY
One year on parts and labor
NOTE
The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.

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1.3 WRM-10P S2 Controls and Indicators
The WRM-10P S2's controls and indicators are shown in Figure 1. The purpose of the controls
and indicators may seem obvious, but users should become familiar with them before using the
WRM. Accidental misuse of the controls will usually cause no serious harm. Users should also
be familiar with the safety summary found on the front page of this User’s Manual.
Figure 1. WRM-10P S2 Controls and Indicators

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2.0 PRE-TEST SETUP
2.1 Operating Voltages
The WRM’s operating voltage is preset at the factory and is selectable between 100-120 Vac,
50/60 Hz or 200-240 Vac, 50/60 Hz.
2.2 LCD Screen Contrast Control
To increase the LCD screen contrast, press and hold the [] key for two seconds.
To decrease the LCD screen contrast, press and hold the [] key for two seconds.
2.3 Printer Paper Control
To advance the WRM printer paper, press and release the [] key.
To retract the WRM printer paper, press and release the [] key.
2.4 Printer Paper
The WRM’s built-in thermal printer uses 2.5" wide thermal paper for printing test results. To
maintain the highest print quality and to avoid paper jams, the use of thermal paper supplied
by Vanguard Instruments is highly recommended. Additional paper can be ordered from the
following sources:
Vanguard Instruments
1520 S. Hellman Avenue
Ontario, CA 91761
Tel: [phone]
Fax: [phone]
Part Number: VIC TP-3 paper
BG Instrument Co.
13607 E. Trent Avenue
Spokane, WA 99216
Tel: [phone]
Fax: [phone]
Part Number: VIC TP-3 paper