HDB-E Handheld Transformer Ratio Group Tester Technical Performance Introduction

1 Overview

During the production process of semi-finished and finished products of power transformers, before the newly installed transformers are put into operation, and according to the preventive test procedures of the State Grid, it is required to regularly test the turns ratio or voltage ratio of the operating transformers. The traditional ratio bridge is cumbersome to operate, the readings are not intuitive, and necessary conversions must be performed. The test result is only the value of one phase ratio. This handheld transformer ratio tester overcomes the shortcomings of traditional ratio bridge testing. The screen uses a large-screen high-resolution LCD display and is powered by lithium batteries. It is convenient for on-site use and has a Chinese menu prompt function. The operation is simple and intuitive. It completes the three-phase ratio test at one time, with fast test speed and high accuracy.

2 Performance characteristics  

2.1 AC/DC dual-use: lithium battery powered or 220V AC charger powered adaptively.

2.2 Once charged, it can continuously measure 100 transformer ratio groups.

2.3 Intelligent charging management, remaining power display, low power alarm, automatic backlight adjustment, saving power.

2.4 Full three-phase sinusoidal inverter power output, automatic output voltage adjustment, with soft start and soft stop functions, so the test speed is fast and the accuracy is high.

2.5 Three-phase transformer, single-phase transformer, PT, Z-type transformer ratio, group, polarity test function.

2.6 It has a blind test function, that is, it can perform ratio and group tests when the high and low voltage connection methods are unknown.

2.7 CT ratio polarity test function.

2.8 It has the function of angle difference test during single-phase test.

2.9 The maximum tapping position can be tested is 197.

2.10 The test range is wide, up to 10000.

2.11 High and low voltage reverse connection protection function.

2.12 Output short circuit protection function.

2.13 Clock and date display without power failure; data storage methods include local storage and USB storage, where the local storage can store 500 test data, and the local storage can be transferred to the USB flash drive; the data format of the USB flash drive storage is Word format, which can be directly edited and printed on the computer.

2.14 Small size, light weight, easy to carry and use.

3 Technical indicators

3.1 Range: 0.9～10000

3.2 Accuracy: ±(reading × 0.1% + 2 digits) (less than or equal to 500)    

±(reading×0.2%+2 characters) (greater than 500 and less than or equal to 3000)

±(reading×0.3%+2 digits) (greater than 3000)

3.3 Resolution: 0.9～9.9999（0.0001） 100～999.99（0.01） 10000 and above（1）

10～99.999（0.001）    1000～9999.9（0.1）

3.4 Working power supply: built-in battery or external charger, charger use conditions, input 100-240VAC, 50/60Hz

1.  

1. Charging time: about 5 hours

3.6 Instrument weight: 1.34 kg

3.7 Instrument volume: 246mm (length) × 156mm (width) × 62mm (height)

3.8 Operating temperature: -10℃～50℃

3.9 Relative humidity: <90%, no condensation

4 Panel Introduction

Figure 1

4.1 High voltage test terminal: Yellow, green and red terminal blocks, corresponding to phases A, B and C respectively, and red test line with spring rod

The other end of the test line has three color test clamps: yellow, green and red, which are connected to the transformer under test.

The A, B, and C phases on the high voltage side of the device.

4.2 Low voltage test terminal: Yellow, green and red terminal blocks, corresponding to phases a, b and c respectively, and black test wire with spring rod

The other end of the test line has three color test clamps: yellow, green and red, which are connected to the transformer under test.

The a, b, and c phases on the low-voltage side of the device.

4.3 Display screen: 320×240 dot matrix LCD with LED backlight, displaying operation menu and test results.

4.4 Buttons: Used to operate the instrument. “↑↓” is the “up and down” key, used to select, move or modify data; “←→”

The "left and right" keys are used to select to move or modify data; the "confirm" key is used to confirm the current operation; the "return" key is used to confirm the current operation.

Press the "Cancel" key to abandon the current operation.

4.5 USB interface: For external USB flash drive to store test data. Please use a USB flash drive in FAT or FAT32 format.

During the storage process, it is strictly forbidden to remove the USB flash drive.

4.6 Grounding terminal: The instrument must be grounded reliably. The on-site grounding point may be covered with paint or rust, which must be cleaned.

4.7 Power switch: The power switch of the whole machine.

4.8 Charging: Please use the charger that comes with the instrument.

1 Test wiring

Connect the test leads correctly according to the condition of the test object.

5.1.1 Single-phase transformer or single-phase PT test wiring

The yellow and green test clamps of the red test line at the high-voltage test end are connected to the high-voltage end of the product under test; the yellow and green test clamps of the black test line at the low-voltage test end are connected to the low-voltage end of the product under test.

5.1.2 Single-phase CT test wiring

The yellow and green test clamps of the red test line at the high-voltage test end are connected to the secondary side of the product under test; the yellow and green test clamps of the black test line at the low-voltage test end are connected to the primary side of the product under test.

5.1.3 Three-phase transformer test wiring

The yellow, green and red test clamps of the red test line at the high-voltage test end are connected to the A, B and C phases of the high-voltage end of the product under test; the yellow, green and red test clamps of the black test line at the low-voltage test end are connected to the a, b and c phases of the low-voltage end of the product under test.

5.2 Intelligent Power Management

When the instrument is not operated for a long time, the LCD backlight will be dimmed automatically to save power. The instrument has low-battery charging reminder function and over-discharge protection function. When the instrument is low on power, it can be charged by plugging in a charger, and the instrument can be operated normally during the charging process.

5.3 Operation

After all the test wires are connected, turn on the power switch, and the instrument will enter the "Main Menu" screen after initialization (see Figure 2).

Figure II

At this time, the top bar displays the instrument running time and battery power icon, the middle displays the instrument model, manufacturer information, and function options, and the bottom displays the software version number and instrument number.

Press the "Up, Down" and "Left, Right" keys to select the corresponding function option, and press the "Confirm" key to enter the selected function menu.

5.3.1 Transformation ratio test

• Three-phase test: ordinary three-phase transformer test.

• Single-phase test: single-phase transformer, PT, CT test.

• Z-type test: Z-type transformer test.