Varistor Tester - Yangzhou Darui - Yangzhou Darui Electric Co., Ltd.

Varistor Tester - Yangzhou Darui

Published: 2020-08-27 09:55:48

Category: Lightning Arrester Tester

Product Description

Varistor Tester

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The varistor tester features a digital measurement system with good stability and high accuracy. Test results are displayed on a three-and-a-half-digit LCD with memory function, providing clear and intuitive readings.

Main Features

>The tester employs high-frequency high-voltage technology, integrating high-voltage generation, control, and measurement into a large closed-loop system to produce high-precision constant current and constant voltage sources. It features multiple protections for safety and reliability. The entire testing process is completed automatically within seconds by simply pressing the measure button. Manual adjustment allows measurement of leakage current at any voltage.

Technical Specifications

>Measurement Range: Varistor Voltage: 0—1999V

>Leakage Current: 0-1999μA

>Constant Current: 1mA, 10mA, 20mA, 30mA, 40mA (customizable per customer requirements)

>Resolution: Voltage: 1V

>Current: 1μA

>Accuracy: Voltage: 1% + 2 digits

>Current: 1% + 2 digits

>Constant Current: 1% + 2 digits

>Power Supply: 220V±10% 50Hz

Test Range

The LYYM-C zinc oxide varistor tester is used to measure the varistor voltage (UnmA) and leakage current (Id) at 0.5UnmA of high-energy zinc oxide varistors.

Usage Instructions

Power Supply

The back panel of this unit is equipped with an external power jack. When in use, insert the dedicated DC12V power adapter provided with the instrument into the power jack, with the core wire being the "+" pole. If preparing your own power cord, pay attention to polarity and wire gauge.

Preparation

1. Set all latching buttons on the front panel to the high position, turn the "High Voltage Limit" knob clockwise to the end (maximum), and turn the "Voltage Preset" knob counterclockwise to the end (minimum). Insert the provided test leads into the "+" and "—" test jacks on the panel. Connect the external power supply to the corresponding power socket (jack) on the back panel.

2. Turn on the power switch. If the display shows "000", the instrument is normal. Otherwise, it is abnormal; please contact after-sales personnel promptly.

Testing

1. Varistor Testing

Set the "Varistor/Discharge Tube" selector switch to the high position (varistor), and the "Single/Continuous" switch to the high position (single). Connect the test sample as described in section 2.2.1 above.

Press the "High Voltage On/Off" key to turn on high voltage, then press the "Test" key. The display will immediately show the breakdown voltage (U1mA) of the varistor under test, in volts (V). After about 2 seconds, the display will automatically show the leakage current (I0.75U1mA) in microamps (μA), and the green indicator light will illuminate simultaneously with the leakage current display, lasting about 2 seconds before disappearing.

2. Discharge Tube Testing

1) Conventional Method (Recommended)

Set the "Varistor/Discharge Tube" selector switch to the low position (discharge tube), and the "Single/Continuous" switch to the high position (single). Connect the test sample as described in section 2.2.1 above.

Press the "High Voltage On/Off" key to turn on high voltage, then press the "Test" key. The test voltage rises from the preset voltage value at a rate of 100V/S until the green indicator light illuminates. At this point, the voltage displayed on the screen is the ignition voltage of the discharge tube under test.

2) Screening Method

a) Set the "Varistor/Discharge Tube" selector switch to the low position (discharge tube), and the "Single/Continuous" switch to the high position (single). Turn the "Voltage Preset" knob clockwise to the end (maximum). Press the "High Voltage On/Off" key to turn on high voltage; the high voltage indicator will light up, and the display will show the maximum output voltage of the instrument. Adjust the "High Voltage Limit" knob to the desired value (upper limit of test range). Then adjust the "Voltage Preset" knob to select the desired voltage value (lower limit of test range).

b) Connect the discharge tube under test to the test leads and press the "High Voltage On/Off" key. If the buzzer sounds an audible alarm, it indicates that the ignition voltage Vsdc of the discharge tube under test is less than the "Voltage Preset" value (below the lower limit). In this case, turn off the high voltage promptly and remove the test sample; otherwise, it will be repeatedly ignited. If the buzzer does not sound, it indicates that the ignition voltage Vsdc is greater than the "Voltage Preset" value. You can press the "Test" key to proceed to the next step.

c) After pressing the "Test" key, the test voltage rises from the preset voltage value at a rate of 100V/S. After the green indicator light illuminates:

(1) If the buzzer does not sound, the display will show the ignition voltage value of the discharge tube under test within the measurement range.

(2) If the buzzer sounds, the display will show the upper limit of the measurement range. This indicates that the ignition voltage Vsdc of the test sample is greater than the upper limit of the measurement range (exceeding the upper limit) and has not ignited. In this case, increase the "Upper Limit of Test Range" and repeat the test.

The green indicator light and the simultaneously generated display value (with buzzer sound when exceeding the range) will disappear after about 2 seconds, then return to the preset state.

While the green indicator light is on, remove the tested discharge tube, and after the preset voltage is restored, connect the next discharge tube for testing.

3) Continuous Measurement

Set the "Single/Continuous" switch to the low position (continuous) to perform continuous measurements.

Self-Check and Others

1. Checking the 1mA value for varistor testing

Select "Varistor" test, turn on high voltage, adjust the preset voltage to above 10V, short-circuit the "+" and "—" terminals of the test jacks. The display should show "000". Press and hold the "Display Conversion" key; it should show "1000". If the displayed value deviates significantly, the instrument may have issues; please contact after-sales personnel promptly.

2. Checking the 0.75U1mA value for varistor testing

With the test terminals open, press the "Test" key to perform a test. The display should show the upper limit of the range. While the green light is on, press and hold the "Display Conversion" key; it should show 0.75 times the upper limit of the range.

3. During testing, press and hold the "Display Conversion" key: during the U1mA measurement period, it displays the test condition of 1mA (1000μA); during the I0.75U1mA measurement period, it displays the test condition of 0.75U1mA.

Additionally, using the voltage preset and range adjustment functions, the instrument can be used as a 1999V/1mA DC regulated voltage source and a 1mA constant current source (when the load current reaches 1mA, the instrument outputs a constant 1mA test current). Combined with the "Display Conversion" key, it can measure load voltage and current (V/I characteristics).

After Testing

Press the "High Voltage On/Off" key to turn off the test voltage, then turn off the power switch. If using an external DC 12V power supply, remove the power cord.

Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.

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