How to use insulation resistance tester?

Insulation resistance is generally measured with an insulation resistance tester. Insulation resistance tester is mainly used to check the insulation resistance of electrical equipment, household appliances or electrical lines to ground and between phases. It is suitable for measuring the resistance value of various insulating materials and the insulation resistance of transformers, motors, cables and electrical equipment. It is an important tool for electric power , post and telecommunications, communications, mechanical and electrical installation and maintenance, and industrial enterprise sectors that use electricity as industrial power or energy are commonly used and indispensable instruments.

Principle of insulation resistance tester:

The insulation resistance tester mainly excites the device or network under test with a voltage, then measures the current generated by the excitation, and uses Ohm's law to measure the resistance. For example, these electrical testers apply much higher voltages when making resistance measurements than the ohmmeter function found on digital multimeters (DMMs). Megohmmeters typically operate on voltages ranging from 50V up to 5kV; typical digital multimeters typically operate on voltages less than 10V. For insulation testing, the resistance value range that needs to be measured is large, the upper limit can reach 10TΩ, and the required voltage is higher.

Insulation resistance tester performance:

Electrical Insulation resistance testers, often called megohmmeters or megohmmeters, are widely used to measure the insulation of generators, motors, power transformers, wiring, appliances, and other electrical devices such as cables for control, signaling, communications, and power supplies. resistance. They are often used during routine maintenance procedures to indicate changes in a motor's insulation resistance over months or years. Large changes in insulation resistance may indicate potential failure. Therefore, the megohmmeter needs to be calibrated regularly to ensure that the meter itself has not changed over time.

application:

Preparation

Make sure the test instrument and the device under test are in a safe state and disconnected from the power supply. Check whether the test equipment is working properly. (Discharge, no sparks, with insulating mats on the ground)

Connect wiring

Connect the test instrument's test leads (generally red and black) to the insulated part of the device under test. Make sure the leads are securely connected and do not come loose or fall off during testing.

Select test mode

Choose the appropriate test mode according to your needs. Usually the insulation resistance tester has a DC test mode and an AC test mode. Select the appropriate test mode based on the requirements of the device under test.

Set test parameters

Set test parameters according to the requirements of the device under test, such as test voltage, test time, etc. Make sure that the set parameters meet the specifications of the device under test.

carry out testing

Press the test button or switch on the test instrument to start the test. During the test process, the test instrument will output the test voltage and measure the insulation resistance value of the device under test.

Record results

After the test is completed, record the test results. If the test results meet the specifications, the insulation performance of the equipment under test is good; if the test results do not meet the specifications, further inspection and repair of the equipment under test are required.

end work

After the test is completed, disconnect the test leads, turn off the test instrument, and place the test instrument in a safe place. Before connecting the device under test to power, ensure that all test operations have been completed and meet safety requirements.

When using an insulation resistance tester, you need to pay attention to safe operation, correctly connect the test leads, select the appropriate test mode and parameters, conduct accurate tests, record the test results, and do the finishing work after the test is completed. If you are not sure how to operate, it is recommended to refer to the instruction manual of the test instrument or seek help from professionals.