This document describes a 5kV High Voltage Insulation Tester, a microprocessor-controlled instrument designed for measuring insulation resistance, AC/DC voltage, and short-circuit current. It offers a range of features for comprehensive electrical testing and data management.

Function Description

The primary function of this device is to perform high voltage insulation resistance tests. It can output test voltages of 500V, 1000V, 2500V, and 5000V, allowing for testing across various insulation levels. Beyond basic resistance measurement, the tester also provides indications for Polarization Index (PI) and Dielectric Absorption Ratio (DAR). These ratios are crucial for assessing the condition and quality of insulation over time. A lower insulation resistance tested typically requires a longer test time, which can deteriorate the specimen. Conversely, higher DAR or PI values (closer to 1) generally indicate a better insulation grade of the specimen.

In addition to insulation testing, the device functions as an AC/DC voltmeter, capable of measuring voltages between 30V and 600V. It also measures short-circuit current up to 5mA.

The instrument incorporates several minor functions for enhanced usability and data management. These include date/time adjustment, measurement time setting (adjustable from 1 to 30 minutes), display of stored data, and deletion of stored data. The device can save up to 200 measurement results in its internal memory, which can then be recalled and displayed.

Usage Features

The tester is designed for ease of use with a high-contrast OLED display and auto-ranging on all insulation ranges. Before any test, it is crucial to ensure that the circuit under test is de-energized and disconnected. The instrument features a live circuit warning beeper and displays a warning message if connected to a live circuit (≥30Vac or ≥30Vdc), preventing accidental testing and ensuring operator safety.

Measuring Procedure:

Connection: Connect the specimen using the provided test cables. The manual illustrates how to connect the "LINE," "GUARD," and "EARTH" terminals. A "first measurement" without the guard terminal is recommended to account for all factors and determine if cleaning is needed. A "second measurement" with the guard terminal helps ensure the insulator itself is correct.
Power On & Voltage Selection: Turn the function rotary switch to power on the device and select the desired test voltage (500V, 1kV, 2.5kV, or 5kV).
External Voltage Check: The device automatically checks for external voltage. If an exterior voltage (above AC30V or DC30V) is detected, a beeper will activate, and the LCD will display a warning, preventing the test from proceeding until the external voltage is removed.
Initiating Test: Press the "TEST/STOP" button to start the test. The button can be rotated to a locked position for continuous testing. During the test, a beeper reminds the operator that the test is underway.
Test Completion: After the set test time (configured via Function 2), the test automatically stops, and the system locks down the test value for reading on the LCD display.
Data Storage: To store the measurement data, press the "ENTER/SAVE" button. The device will display a confirmation of the stored data, including resistance value, testing voltage, and elapsed time.

Other functions include:

Dielectric Absorption Ratio (DAR): Automatically displayed after one minute during a test run.
Polarization Index (PI): Automatically displayed after ten minutes during a test run.
Auto-hold function: Freezes the reading on the display.
Auto-off function: The system automatically shuts down after 3 minutes of inactivity to conserve battery.

Interface Connection and Operation: The device supports data transmission via an optical USB to RS-232 connection. It comes with a data transmission cable and a compact disk (CD) for the PC interface software.

Software Installation: The 5KV Insulation Tester program is installed automatically on the computer. Users follow on-screen prompts to complete the installation.
Comm Port Setting: After connecting the data transmission cable to the computer's USB port, users need to identify the correct "Comm Port" in the computer's Device Manager (typically under "Universal Serial Bus Controllers" as "USB Serial Port (COMX)").
Software Connection: In the 5KV Insulation Tester software, select the identified "Comm Port" and click the RS 232 connection button to establish communication.
Data Download & Display: The software interface allows users to download logged data from the device, which can then be viewed as a list or as a chart displaying resistance and current diagrams over time. The data can also be saved to a file.

Maintenance Features

Proper maintenance ensures the longevity and safe operation of the 5kV High Voltage Insulation Tester.

Protection from Moisture and Physical Damage: Avoid wetting the inner part of the tester to prevent electric shock or device damage. The device should also be protected from being dropped, which could damage or disconnect internal components.
Cleaning: The tester's surface should be wiped with a soft, dry cloth and a mild detergent. Abrasive materials like sandpaper or solvents are strictly prohibited as they can damage the casing.
Battery Management: If the tester is not used for an extended period, it should be charged at least once per month to prevent battery deterioration. The device indicates "Low Battery" on the LCD display when charging is required. During the charging process, no measurements can be performed.
Professional Repair: This tester operates at high voltage, and users should not open the outer casing. In case of any damage or malfunction, the device must be returned to the manufacturer or an authorized service center for repair by competent personnel.
Pre-use Inspection: Always inspect the tester and test leads for any signs of abnormality or damage (e.g., broken leads, cracked case, faulty display) before use. If any such conditions exist, do not attempt to use the tester and return it for service.

Safety Precautions:

The instrument must only be used by competent, trained personnel in strict accordance with instructions and safety procedures.
Always ensure all circuits are de-energized before testing.
Wear insulation gloves and rubber shoes when operating this high-voltage measuring instrument.
During the test, do not touch any metal on the specimen surface or the test cable.
After testing, allow a few seconds for the HV insulation tester to discharge the circuit under test. The discharging status can be checked on the display.

Mitchell MIT6501 - Page 26

Table of Contents