1520 S. Hellman Ave.
Ontario, California 91761, USA
TEL: (909) 923-9390
FAX: (909) 923-9391
February 2014
Revision 2
ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
SAFETY SUMMARY
This manual applies to the ATRT-03 S2, ATRT-03A S2, and ATRT-3B S2 current transformer
turns-ratio meters. The operating procedures are virtually the same for all three models, and
any differences are clearly described where applicable.
FOLLOW EXACT OPERATING PROCEDURES
Any deviation from procedures described in this User’s Manual may create one or more safety
hazards, damage the ATRT-03/03A/03B S2, damage the test transformer, or cause errors in the
test results. Vanguard Instruments Company, Inc. assumes no liability for unsafe or improper
use of the ATRT-03/03A/03B S2.
SAFETY WARNINGS AND CAUTIONS
The ATRT-03/03A/03B S2 shall be used only by trained operators. All transformers under test
shall be off-line and fully isolated. Always ground the ATRT-03/03A/03B S2 to a substation
ground before connecting the test cables to a transformer. Do not perform test procedures or
service unless another person is also present who is capable of rendering aid and resuscitation.
DO NOT MODIFY TEST EQUIPMENT
To avoid the risk of introducing additional or unknown hazards, do not install substitute parts or
perform any unauthorized modification to any ATRT-03/03A/03B S2 test unit. To ensure that all
designed safety features are maintained, it is highly recommended that repairs be performed
only by Vanguard Instruments Company factory personnel or by an authorized repair service
provider. Unauthorized modifications can cause safety hazards and will void the manufacturer’s
warranty.
WARNING
Do not remove test leads during a test. Failure to heed this warning can result in electrical
shock to personnel and damage to the equipment.
The ATRT-03 S2 line is Vanguard’s third generation family of microprocessor-based, automatic,
three phase, transformer turns-ratio testers. The ATRT-03 S2 line consists of the following three
models:
• The ATRT-03 S2 is a line-powered, 100-240 Vac, 50/60 Hz turns-ratio tester featuring a
built-in thermal printer.
• The ATRT-03A S2 can be powered either by an internal rechargeable lead acid battery,
by 100-240 Vac, or by a 12 Vdc external source. The internal battery provides 3 hours of
operational time. The ATRT-03A S2 also features a built-in thermal printer.
• The ATRT-03B S2 is a line-powered, 100-240 Vac, 50/60 Hz turns-ratio tester without a
built-in thermal printer.
The general term “ATRT-03 S2” or “ATRT” is used in this manual to refer to any of the ATRT-03
S2 models. Any differences are clearly described where applicable.
The ATRT-03 S2 determines the transformer turns-ratio using the IEEE C57.12.90 measurement
method. The ATRT-03 S2 outputs an excitation test voltage to the transformer’s primary
windings. The induced secondary voltage is sensed and the transformer turns-ratio is
calculated. The unit can measure turns-ratios from 0.8 to 15,000. The transformer turns-ratio,
excitation current, and phase-angle readings are displayed on the large back-lit LCD. The built-in
transformer type detection feature allows the ATRT-03 S2 to detect and test 130 transformer
types defined by ANSI, CEI/IEC and Australian standards.
The ATRT-03 S2 can be used as a stand-alone unit or can be computer-controlled. It can be
operated locally using its alpha-numeric keypad and rotary switch. Information is displayed on a
back-lit LCD screen (64 x 128 dot graphic) that is viewable in both bright sunlight and low-light
levels. Test reports can be printed in the field on the unit’s built-in 4.5-inch wide thermal
printer (ATRT-03 S2 and ATRT-03A S2 only). The ATRT-03 S2 can store up to 112 test records
and 128 test plans in Flash EEPROM. Test records or test plans can be stored or transferred to
and from a PC via the available interfaces (RS-232C port, USB port, USB Flash drive port).
Transformer Test Voltage
To prevent an accidental wrong test-lead hook-up (e.g., when the operator reverses H and X
leads), the ATRT-03 S2 outputs a low-level test voltage to verify the hook-up condition before
applying the full test voltage to the transformer. Three test voltages (8 Vac, 40 Vac, 100 Vac)
allow the ATRT-03 S2 to test CT’s and PT’s, as well as power transformers.
Auto-Detect Transformer Configuration
The ATRT-03 S2 can automatically detect 130 specific vector groups for different transformer
types defined by ANSI, CEI/IEC, and Australian standards.
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ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
User Interface
The ATRT-03 S2 features a back-lit LCD screen (64 x 128 dot graphic) that is viewable in both
bright sunlight and low-light levels. The test results screen displays the transformer turns-ratio,
excitation current, phase angle, and percentage error. The unit is controlled via a rugged, 16key, membrane keypad and a digital rotary switch.
Transformer Test Plans
The ATRT-03 S2 can store up to 128 transformer test plans in its Flash EEPROM. A test plan is
comprised of the transformer nameplate voltages for each tap setting. The calculated turnsratio based on the nameplate voltages is compared with the measured turns-ratio. By recalling
a test plan, a transformer can be quickly tested and turns-ratio Pass/Fail reports can be
reviewed. Test plans can be created with the PC software and can be transferred to the ATRT03 S2 via the available interfaces (RS-232C port, USB port, USB Flash drive port).
Internal Test Record Storage
Up to 112 test records can be stored in the ATRT-03 S2’s Flash EEPROM memory. Each test
record may contain up to 33 turns-ratio, excitation current, phase angle and name plate voltage
readings. Test records can be recalled locally or transferred to a PC via the available interfaces
(RS-232C port, USB port, USB Flash drive port).
USB Flash Drive Interface
A built-in USB Flash drive interface provides a convenient method for transferring test plans
and test records to or from a USB Flash drive. The user can store up to 999 transformer test
plans on a USB Flash drive. Test plans can be transferred from a PC to a USB Flash drive, and
then a specific test plan on the USB Flash drive can be transferred to the ATRT-03 S2’s internal
Flash memory. Up to 999 test records from the field can be stored on a USB Flash drive. Test
records stored in the ATRT-03 S2’s internal memory can also be transferred to a USB Flash
drive. The supplied PC software can then be used to view the test records stored on the USB
Flash drive.
Computer Interface
In computer-controlled mode, the unit can be controlled via the RS-232C or USB port using the
supplied PC software (Transformer Turns-Ratio Analyzer application provided with each ATRT03 S2). This Windows® XP/Vista-based software can be used to run a test and to store test
results on a PC. Test results can also be exported to Microsoft® Excel.
Transformer Load Tap Changer Control
Transformer tap positions can be changed remotely using the unit’s built-in transformer load
tap changer. This remote-controlled tap changer feature eliminates the need to manually
change a transformer’s step-up and step-down taps.
Built-in Thermal Printer (ATRT-03 S2 and ATRT-03A S2 only)
The ATRT-03 S2 and ATRT-03A S2 feature a built-in 4.5-inch wide thermal printer that can print
test results. The printer and paper dispenser are mounted under the front panel for protection.
XP/Vista-based Transformer Turns-Ratio Analyzer application is
included with purchase price
Can store 112 transformer test records internally. Each record holds the test
record header and up to 33 readings per phase. The readings include turns
ratio readings, excitation current readings, and nameplate voltages.
Can store 128 transformer test plans internally. Test plans can be transferred
to the unit from the PC via the RS-232C/USB port or via the USB Flash drive
interface
240 Vac, 2 Amps
standards
+158˚ F)
extension set, One safety ground, One USB, One RS-232C, One LTC cable,
cable bag
The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.
NOTE
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ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
®
1.2.2. ATRT-03A S2 Technical Specifications
Table 2. ATRT-03A S2 Technical Specifications
TYPE Portable, lightweight, automatic, 3-phase transformer turns-ratio meter
PHYSICAL SPECIFICATIONS20”W x 7.5”H x 15.5”D (50 cm x 19 cm x 39.6 cm); Weight: 27 lbs (12 kg)
OPERATING VOLTAGE 100 – 240 Vac, 50/60 Hz
BATTERIESTwo lead acid batteries (12V, 2 AH) provide up to 3 hours of operation
XP/Vista-based Transformer Turns-Ratio Analyzer application is
included with purchase price
Can store 112 transformer test records internally. Each record holds the test
record header and up to 33 readings per phase. The readings include turns
ratio readings, excitation current readings, and nameplate voltages.
The unit can store 128 transformer test plans. Test plans can be transferred
to the unit from the PC via the RS-232C/USB port or via the USB Flash drive
interface
240 Vac, 1 Amp
standards
+158˚ F)
extension set, One safety ground, One USB, One RS-232, One LTC cable,
cable bag
The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.
XP/Vista-based Transformer Turns-Ratio Analyzer application is
included with purchase price
Can store 112 transformer test records internally. Each record holds the test
record header and up to 33 readings per phase. The readings include turns
ratio readings, excitation current readings, and nameplate voltages.
Can store 128 transformer test plans internally. Test plans can be transferred
to the unit from the PC via the RS-232C/USB port or via the USB Flash drive
interface
240 Vac, 2 Amps
standards
+158˚ F)
extension set, One safety ground, One USB, One RS-232C, One LTC cable,
cable bag
The above specifications are valid at nominal operating voltage and at a
temperature of 25°C (77°F). Specifications may change without prior notice.
NOTE
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ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
1.3 Controls and Indicators
The ATRT-03 S2, ATRT-03A S2, and ATRT-03B S2 controls and indicators are shown in Figure 1,
Figure 2, and Figure 3, respectively. A leader line with an index number points to each control
and indicator, which is cross-referenced to a functional description in the corresponding table.
The purpose of the controls and indicators may seem obvious, but users should familiarize
themselves with them before using the ATRT. Accidental misuse of the controls will usually
cause no serious harm. Users should also familiarize themselves with the safety summary
information found on the front page of this User’s Manual.
Table 6. Functional Descriptions of ATRT-03B S2 Controls and Indicators
Item
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Panel Markings Functional Description
EMERGENCY
TURN-OFF
“PUSH”
H H voltage connector.
USB
MEM
X X voltage connector.
LTC
CONTROL
120-240 Vac, 2A, 50-60 Hz
Fuse: 250Vac, 5A Fast-Blow
GROUND Ground stud for connecting to sub-station ground.
CHANGE
“PUSH”
TO SELECT
LTC
CONTROL
Rugged alpha-numeric keypad.
TEST
IN
PROGRESS
RS-232C RS-232C PC interface connector.
USB
PC
Emergency turn off test voltage switch.
Back-lit LCD screen (64 x 128 dot graphic), viewable in bright sunlight
and low-light levels.
USB Flash drive interface port.
Load Tap Changer controller connector.
Input power connector and fused power switch with third-wire safety
ground.
Control knob. You can scroll through menu items by turning the control
knob. A highlighted menu item can be selected by pushing the control
knob.
Load Tap Changer control buttons.
This LED flashes in response to commands or when a test voltage is
applied to the test transformer.
USB PC interface connector.
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ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
2.0 PRE-TEST SETUP
2.1 Operating Voltages
All three ATRT-03 S2 models can be powered by ac line voltage of 100-240 Vac, 50/60 Hz. For
greater flexibility, the ATRT-03A S2 features an internal rechargeable lead acid battery and can
also be powered by a 12 Vdc external source. The ATRT-03 S2 has built-in ground fault isolation
detection and will only operate with voltages that are ground-fault isolated.
2.2 LCD Screen Contrast Control
To increase the LCD screen contrast, press and hold the [PAPER ∧ Contrast] key for two
seconds. Release the button when the desired contrast level has been reached.
To decrease the LCD screen contrast, press and hold the [PAPER ∨ Contrast] key for two
seconds. Release the button when the desired contrast level has been reached.
2.3 Printer Paper Control
To advance the thermal printer paper, press and release the [PAPER ∧ Contrast] key.
To retract the thermal printer paper, press and release the [PAPER ∨ Contrast] key.
2.4 Printer Paper
The ATRT-03 S2 and ATRT-03A S2’s built-in thermal printers use 4.5-inch 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 Company is highly recommended. Additional
paper can be ordered from the following sources:
Vanguard Instruments Co, Inc.
1520 S. Hellman Avenue
Ontario, CA 91761
Tel: 909-923-9390
Fax: 909-923-9391
Part Number: VIC TP-4 paper
BG Instrument Co.
13607 E. Trent Avenue
Spokane, WA 99216
Tel: 509-893-9881
Fax: 509-893-9803
Part Number: VIC TP-4 paper
2.5 Replacing the Load Tap Changer Controller Fuses
The ATRT-03 S2 features a built-in Load Tap Changer (LTC) controller that can raise or lower the
LTC tap position from the front panel. The LTC controller circuit uses two 250 Vac/2A, NO, relay
contacts to simulate the LTC Raise/Lower switches. Each relay contact is protected by a 1A/250
Vac fuse (5 X 20mm, fast acting). The fuse should be replaced with a Littlefuse P/N 217001 or
equivalent. Follow the instructions below to replace the LTC controller fuses:
a. Remove the ATRT-03 S2 from its casing by removing the four screws from the bottom of
the case:
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ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
b. The LTC control board is located under the left side of the front panel as shown in the
figure below. Flip the unit over to easily access the LTC control board fuses.
c. Replace any fuses as necessary with Littlefuse P/N 217001 or equivalent (250 Vac/1A, 5
X 20mm fast-acting type).
d. Re-secure the unit in its casing with the screws that were removed in step a.
The ATRT-03 S2 should always be grounded with the provided ground cable before connecting
H and X cables. The transformer bushings should also be grounded before connecting test leads
to the transformer. This will prevent inducing any voltages into the ATRT-03 S2. All transformer
bus connections must be removed, and the transformer must be isolated before performing
any tests. Typical transformer connection diagrams are illustrated in the sections below.
3.1 Connection Diagrams
3.1.1. Typical Front Panel Connections
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Figure 4. Typical Front Panel Cable Connections
ATRT-03 S2, ATRT-03A S2, AND ATRT-03B S2 USER’S MANUALREV 2
3.1.2. Typical Connections to a Load Tap Changer (LTC)
Figure 5. Typical Connections to a Load Tap Changer (LTC)