The Iintroduction of Electrical Safety Test Equipment on Effective Electrical Safety Testing

Electrical safety test equipments are used for high voltage component insulation test (with AC or DC withstanding voltage tester), such as silicon stacks. It is a special instrument mainly used to detect whether the product leaks electricity, has good grounding, and will not harm personal safety. The main testing items are voltage, leakage current, insulation resistance and grounding resistance.

LISUN LS9955/LS9956 Automatic Safety Test System (electrical safety analyzer) combined the following function in one set: Withstand Voltage Test (AC/DC), Insulation Resistance Test (IR), Leakage Current Test (LLC), Grounding Resistance Test (GR) and Power Test.

The LS9955/LS9956 Automatic Safety Test System is according to GB4706.1, IEC/EN60335-1, UL60335, GB7000, IEC60598, GB4943, IEC60950 and GB9706.1. It is used for luminaries, home application and motor tools safety test in production line or R&D Lab.

Automatic Safety Test System LS9955

I.Usage of Electrical Safety Test Equipment
Different models of test equipments have different functions and settings, so their usage is also different. But for LISUN products of this brand, the usage of desktop and cabinet models are similar. Here is a detailed explanation for you.

Before using the electrical safety test equipment, the device should be installed in the appropriate position, meeting the requirements of keeping away from precision instruments, heat sources, good power supply grounding, and the operator’s dress should meet the regulations without metal decorations. Then, in the power-off state of the equipment, connect the matching test box, test clip, test rod and power cord to the corresponding position on the instrument, paying attention to the numbers on the instrument and the numbers on each accessory. After the accessories are wired and determined, the power can be turned on and the instrument is in standby state. Then, set the test items and parameters according to the requirements of the product, save the test items for direct use of these test conditions during testing. Then the product can be tested. When placing the product, pay attention to place the tested product on the insulating board, so as to keep it electrically insulated from the earth. Then plug the power cord of the tested product into the test box, and place the accessories such as test clip, test rod in the specified position. Start the test by foot switch, start button, barcode scanner (optional) and wait for the test to be completed. The test of one tested product is completed. The next tested product can be wired and tested repeatedly.

II.Four Test Principles of Electrical Safety Test Instruments

The dangers in safety standards include the following four kinds: electrical injury, mechanical / physical injury, low voltage / high energy injury, and fire prevention and control. These four safety standards are the basic safety standards for all kinds of product safety standards. Among them, electrical injury is the greatest harm to users for general electronic products.The test of electrical injury is mainly divided into the following four parts:
· Withstand voltage test: withstand voltage test is applied to the power supply end and ground end circuit of the product, and the collapse state is measured by high voltage and large current.
· Insulation resistance test: measurement of the electrical insulation status of the product.
· Leakage current test: check whether the leakage current of AC / DC power supply to the ground end exceeds the standard.
· Ground protection test: check whether there is effective grounding for contacts such as metal structures.

III.Common Applications of Electrical Safety Test Equipment
1. Verification of electrical safety and reliability.
2. Maintenance of electrical equipment, such as electric motors, generators, wiring and transformers.
3. Type testing and annual inspection of electrical appliances to ensure the reliability of grounding, leakage current and insulation.
4. Production test of electrical appliances to ensure proper grounding and insulation performance.

IV.Test Steps Introduction
1. Insulation resistance test
Insulation resistance test is one of the basic test items of electrical safety test instruments. During the test, the test line needs to be connected to the insulation part of the tested product, and then set the test voltage and test time. After the test is finished, the instrument will display the insulation resistance value. If the insulation resistance value meets the standard requirements, the tested product is qualified.

2. Ground resistance test
Ground resistance test is an important test item for testing the grounding performance of the product. During the test, the test line needs to be connected to the grounding part of the tested product, and then set the test current and test time. After the test is finished, the instrument will display the ground resistance value. If the ground resistance value meets the standard requirements, the tested product is qualified.

3. Leakage current test
Leakage current test is an important test item for testing the leakage situation of the product. During the test, the test line needs to be connected to the power line and ground line of the tested product, and then set the test voltage and test time. After the test is finished, the instrument will display the leakage current value. If the leakage current value meets the standard requirements, the tested product is qualified.

V. Advantages of Electrical Safety Test Equipment
Generally, AC safety test instruments are more acceptable from safety organizations than DC safety test instruments. The main reason is that most of the test subjects will work under alternating current, and alternating voltage test provides the advantage of alternating two poles for insulation pressure, which is closer to the pressure that the product will encounter in actual use. Because AC test will not charge capacitive load, the current readings will be consistent from the beginning of voltage application to the end of test. Therefore, there is no need to increase the voltage, because there is no need to monitor the stability of current readings. This means that, unless the tested product senses the sudden voltage application, the operator can immediately apply the full voltage and read the current, without waiting. Since AC voltage does not charge the load, there is no need to discharge the tested device after testing.

VI.Defects of Electrical Safety Test Equipment
When testing capacitive load, the total current is composed of reactive current and leakage current. If the reactive current is much larger than the actual leakage current, it may be difficult to detect products with excessive leakage current. When testing large capacitive loads, the total current required is much larger than the leakage current itself. Because the operator is facing a larger current, this may be a greater risk.