Vanguard ATRT-01-01B-01D User Manual

OPERATING INSTRUCTIONS

for

Models ATRT-01, ATRT-01B, and ATRT-01D

Single Phase Transformer Turns-Ratio Meter

Vanguard Instruments Co., Inc.

1710 Grevillea Court
Ontario, California 91761

TEL: [phone] May 2002
FAX: [phone] REV. 02

Model ATRT-01 (v) Operating Instructions

1

NOTICE

This manual applies to Models ATRT-01, ATRT-01B, and ATRT-01D; the operating procedures are
virtually the same for all models; any differences, which relate to the test units’ power sources, are
clearly described within the step-by-step procedures.

SAFETY WARNINGS AND CAUTIONS

This device shall be used only by trained operators.

All transformers under test shall be off line and fully isolated

Do not Service or Test alone.

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

Because of the added risk of introducing additional or unknown hazards, do not install substitute
parts or perform any unauthorized modification to any Model ATRT-01 Test unit. To ensure that
all designed safety features are maintained, it is recommended that repairs be performed only by
Vanguard Instrument Co. factory personnel or by an authorized repair service. Unauthorized
modifications can cause serious safety hazards and will nullify the manufacturer's warranty.

Follow Exact Operating Procedures

Any deviation from procedures described in this operator’s manual may create one or more safety
hazards, damage the ATRT-01 or the test transformer, or cause errors in the test results; VIC
assumes no liability for unsafe or improper use of the ATRT-01.

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

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Table of Contents

1.0 Introduction ............................................................................................................................4

2.0 Applicability...........................................................................................................................4

3.0 Operating Configuration .........................................................................................................4

4.0 Principle of Operation.............................................................................................................5

5.0 Specifications..........................................................................................................................5

6.0 Cable Marking and Identification:...........................................................................................6

7.0 ATRT-01 Operating Controls And Indicators..........................................................................7

8.0 ATRT-01B Operating Control And Indicators.........................................................................8

9.0 ATRT-01D Control And Indicators.........................................................................................9

10.0 ATRT-01 Power Switch Configurations................................................................................10

10.1 ATRT-01 Power Turn On/Off...........................................................................................10

10.2 ATRT-01B Power Turn On/Off.........................................................................................10

10.3. ATRT-01D Power Turn On/Off .......................................................................................10

11.0 ATRT-01B Charger Indicator ...............................................................................................10

12.0 ATRT-01 LCD Control.........................................................................................................10

12.1. Contrast Control...............................................................................................................10

12.2. Display Back-light Control...............................................................................................10

13.0 ATRT-01 RS-232C Computer-Control port ..........................................................................10

14.0 IBM PC Transformer Analysis Software...............................................................................10

15.0 ATRT-01 Battery replacement..............................................................................................11

15-1. ATRT-01B Battery Replacement.....................................................................................11

15-2. ATRT-01D Battery Replacement....................................................................................11

16.0 DISPLAY and MENU DESCRIPTIONS..............................................................................12

16-1 Start-Up Menu..................................................................................................................12

17.0 Test Transformer Selection ...................................................................................................15

18.0 Transformer Voltage Selection..............................................................................................16

19.0 Transformer Voltage Data Entry Menu .................................................................................17

20.0 Start Test Menu.....................................................................................................................19

21.0 Transformer Turns-Ratio Test Result Display .......................................................................20

22.0 Three Phase Transformer Test Cable Connection Display .....................................................21

23.0 Set Time and Date.................................................................................................................22

24.0 Enable Computer Interface....................................................................................................23

25.0 Step-by-Step Turns Ratio Testing Procedures .......................................................................24

25-1 Single-Phase Transformer Test Procedure.........................................................................24

25-2 Single-Phase Transformer Test Procedure using nameplate voltages.................................25

25-3. Three-Phase Transformer Test Procedure using nameplate voltages................................26

25-4 ATRT-01 Quick-Test Mode..............................................................................................28

25-5 Test Single Phase Transformer Using Preset Voltage Table..............................................28

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

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List of Tables

Table 5-1. Model ATRT-01 (v) Turns-Ratio Meter Specifications .................................................5

Table 5-2: ATRT-01, ATRT-01B, and ATRT-01D Cable Set.........................................................6

Table 6-1. Cable Markings and Identification .................................................................................6

Table 25-1. Single-Phase Transformer Test Procedure.................................................................24

Table 25-2. Single-Phase Transformer Test (with name plate voltages) Procedure.......................25

Table 25-3. Three-Phase Transformer Test Procedure..................................................................26

List of Figures

Figure 7-0. Model ATRT-01 Front-Panel Controls, Indicators, and Connectors.............................7

Figure 8-0. Model ATRT-01B Front-Panel Controls, Indicators, and Connectors...........................8

Figure 9-0. Model ATRT-01D Front-Panel Controls, Indicators, and Connectors ..........................9

Figure 16-0 Start-up menu............................................................................................................12

Figure 16-1 ATRT-01 Menu Diagram...........................................................................................13

Figure 17-0 Transformer Selection menu......................................................................................15

Figure 18-0. Nameplate Voltage Selection Menu.........................................................................16

Figure 19-1. H-Winding Voltage Entry Display............................................................................17

Figure 19-2. H-Winding Voltage Entry Display............................................................................17

Figure 19-3. X-Winding Voltage Entry Display............................................................................17

Figure 19-4. X-Winding Voltage Entry Display............................................................................17

Figure 20-0. Start Test Screen......................................................................................................19

Figure 21-0. Test Result Display...................................................................................................20

Figure 22-0. Cable Connection Display........................................................................................21

Figure 23-0. Time and Date Display ............................................................................................22

Figure 24-0. Select Computer Interface Display..........................................................................23

Figure 25-4 Quick Test Menu.......................................................................................................28

Figure 25-5A Preset Voltage Menu...............................................................................................28

Figure 25-5B Test Result Menu....................................................................................................28

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

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1.0 Introduction

The Model ATRT-01 is a microprocessor-based, field-portable, automatic, transformer, turns­ratio test meter designed for on-site measuring of: turns ratios, winding polarity, and no-load
excitation currents of single and 3-phase utility transformers. The ATRT-01 can also test potential
transformers (PTs) and primary current transformers (CTs). The ATRT-01 may not test some
types of donut transformers (i.e., toroidal windings), since its not designed for that application.

2.0 Applicability

The ATRT-01 is available in three models: ATRT-01 (basic), ATRT-01B, and ATRT-01D.

a. The basic ATRT-01 is a line-powered 120/240 V ac (selectable), 50/60Hz unit.
b. The ATRT-01B is powered by a rechargeable lead-acid-gel battery cell. An ATRT-01B

with a fully charged battery will provide a minimum 0f 4 hours of continuous operation. A
built-in charger allows the ATRT-01B’s battery to be recharged while it is testing.

c. The ATRT-01D is powered by 6 D-cell batteries (no ac is used). To conserve battery

power, the ATRT-01D will automatically turn off after sitting idle for 1 minute. A fully
charged set of batteries in the ATRT-01D provides power for up to 200 tests.

3.0 Operating Configuration

The ATRT-01 tests transformer ratio by applying an excitation voltage to primary (H) windings
and monitors secondary (X) winding voltage. The users can also test 3-phase transformers using
the ATRT-01. The user is required to connect the H and X cable leads to the appropriate windings
for each phase. Since the ATRT-01 test lead connections to the (3-phase) transformer bushings are
different for each phase, the ATRT-01 simplifies this procedure by displaying hook-up instructions
on the LCD screen as testing progresses.

The ATRT-01 detects test-lead hook-ups for errors before a test: The ATRT-01 applies a low­level test voltage (300 mV) across the winding being tested and senses the induced secondary
voltages. Any time an induced voltage is greater than the applied excitation voltage, it's detected as
a hookup error. If a cross-connection error is detected, the ATRT-01 aborts the test and displays:
“Hook-Up Error." But, if no hookup error is detected, the ATRT-01 applies a full 40-volt (20-volt
for ATRT-01B/-01D) test voltage to the transformer being tested and the winding (voltage) ratio is
displayed. Excitation current (in milliamperes) and winding polarity are also displayed.

The ATRT-01 lets users enter nameplate voltages for the specified turns-ratio calculation. From
this calculated turns-ratio, the ATRT-01 will calculate and display the percentage of difference
(based on the difference between the calculated and measured values).

A built-in RS-232C port allows the ATRT-01 to interface with an IBM PC. Transformer-testing
program software, supplied with each ATRT-01, runs on an IBM Windows?-based computer and
lets users control the ATRT-01 from a computer in the field. With a computer, users can run a test
and save the test results in the field, then recall the test later in an office to generate a test report.
Since data are stored in an ASCII format, test results can be exported into any database desired.

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

5

4.0 Principle of Operation

The ATRT-01 measures transformer turns ratio by applying a test voltage across the (H) winding
and sensing induced voltage on the secondary (X) winding. (For safety, testing is always done in a
step-down transfer, regardless of the transformer’s actual use.) There's no load on windings during
testing, so measured voltage ratio is virtually the same as the winding turns ratio. The ATRT-01
measures turns ratios in a range from 0.8 to 15,000. Excitation current (via H leads) is measured
for reference and ranges from 0.0 to 2,000 mA (0 to 200 milliamperes for ATRT-01B and ATRT-

01D). Winding polarity is displayed as "+" (in phase) or "-" (out of phase). The ATRT-01
calibrates its own sensing circuits before each test; therefore, calibration by the operator is not
required.

5.0 Specifications

Model ATRT-01(v) specifications are listed below in Table 5-1

Table 5-1. Model ATRT-01 (v) Turns-Ratio Meter Specifications

(Unless otherwise indicated, each specification is the same for all three ATRT-01 models.)

Type Portable, Automatic, Single-Phase Transformer Turns-Ratio Meter
Size (inches) 12 L by 8 W by 9 H
Weight (pounds) ATRT-01: 8, ATRT-01B: 9.5, ATRT-01D: 9.5
Turns Ratio-Measuring Ranges 0.800 to 15,000.00
Turns-Ratio Accuracy 0.8-999: ?0.1 %

1,000-1,499: ?0.2 %
1,500-1,999: ?1.0 %
2,000-15,000: ?2.0%

Calibration Self Calibrating; No operator calibration required
Excitation Voltage ATRT-01: 40 Volts ac, ATRT-01B/ATRT-01D: 20 Volts ac
Excitation Current ATRT-01: 2 amps, ATRT-01B/ATRT-01D: 0 to 200 milliamperes
Current Accuracy ? 2 % of Reading (? 1 Digit)
Winding Polarity Displayed on LCD screen
Display LCD: 20 Characters wide by 4 Lines, viewable in bright sunlight
Serial Interface RS-232C, 19200 baud, 8 data bits, 2 start bits, 1 stop bit
Temperature ? Operating: -20 ?C to 55 ?C ? Storage: -40 ?C to 65 ?C
Warranty One-Year on Parts and Labor

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

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Table 5-2: ATRT-01, ATRT-01B, and ATRT-01D Cable Set

Item Description Qty

1

Test-Lead Cable, 15-foot

1

Single-Phase Connections

2
3

Power Cord (Note 1) 1

RS-232C Cable 1

Note:

1. The ATRT-01D requires no power cord.

2. A Canvas Cable-Carrying Bag is included with the cable set.

6.0 Cable Marking and Identification:

Both H and X cable test leads are terminated with heavy-duty battery clips. Test cables are

identified as follows:

Table 6-1. Cable Markings and Identification

Test Cable Name Transformer Terminals Clip Color Identification

H Cables H Red H1, H2
X Cables X Black X1, X2

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

7

7.0 ATRT-01 Operating Controls And Indicators

Figure 7-0. Model ATRT-01 Front-Panel Controls, Indicators, and Connectors

Fig. 7-0 Index Panel Markings Functional Description

1

2

3
4

RS-232C Computer-Interface port, 9-pin, female DB type

connector; RS-232C interface port allows ATRT-01
to interface with an IBM computer. Data rate is set to
19,200 baud, 1 start bit, 8 data bits, 2 stop bits, and
no parity bit. Connector pin functions are:
PIN SIGNAL
2 Tx
3 Rx
5 Gnd

None (display) LCD screen: 4 line by 20 character; back-lighted,

sunlight readable; Displays menus, test results, and

status readouts.
None High and Low voltage connector, 16-pin male.
120/220Vac, 1A, 50/60Hz Input power connector and fused power switch with

third-wire safety ground.

5 None (Keypad) Pushbutton operating controls, 16-keys.

Rev 02
May 02, 2002

Model ATRT-01 (v) Operating Instructions

8

8.0 ATRT-01B Operating Control And Indicators

Figure 8-0. Model ATRT-01B Front-Panel Controls, Indicators, and Connectors

Fig. 8-0

Panel Markings Functional Description

Index

1

2

3
4

5
6

Rev 02
May 02, 2002

RS-232C Computer-Interface port, 9-pin, female DB type connector; This

RS-232C interface allows ATRT-01B to interface with an
IBM computer. Data rate is set to 19,200 baud, 1 start bit, 8 data
bits, 2 stop bits, and no parity bit.
PIN SIGNAL
2 Tx

3 Rx

5 Gnd

None (display) LCD: 4 line by 20 character screen; backlighted, sunlight

readable; Displays menus, test results, and status readouts.
None (H & X) High voltage and Low voltage connector, 16-pin male.
120/220Vac, 1A,
50/60Hz

Input power connector with third-wire safety ground.

None (Keypad) Pushbutton operating controls, 16-keys.
POWER Power Switch, Momentary contact.

9

9.0 ATRT-01D Control And Indicators

Model ATRT-01 (v) Operating Instructions

Figure 9-0. Model ATRT-01D Front-Panel Controls, Indicators, and Connectors

Fig. 9-2,

Panel Markings Functional Description

Index

1 RS-232C Computer-Interface port, 9-pin, female DB type connector;

This
RS-232C interface port allows the ATRT-01D to interface
with an
IBM computer. Data rate is set to 19,200 baud, 1 start bit, 8
data bits, 2 stop bits, and no parity bit.
PIN SIGNAL
2 Tx
3 Rx
5 Gnd

2 None (display) Liquid-Crystal Display (LCD): 4 line by 20 character screen;

backlighted, sunlight readable; Displays menus, test results,
and status readouts.

3 None (H & X

High voltage and Low voltage connector, 16-pin male.

connector)

4 None (Keypad) Pushbutton operating controls, 16-keys.
5 POWER Power Switch, Momentary.

Rev 02
May 02, 2002