Electrical Safety Performance Test

The equipment for electrical safety performance test is in rapid development of modern science technology; all kinds of electrical and electronic equipment are into all fields of social life and become an important symbol of social civilization and progress.  All kinds of electrical appliances and electronic equipment are used in both urban and rural areas and have rapid popularization, which brings great convenience for production. But the widespread use of electrical appliances and electronic equipment also brings increased accidents and brings harm to life and property, electric shock casualties and electrical fires are common. Therefore, the use safety of electrical appliances and electronic equipment is an important problem; it becomes the leading position of the factors that decide the product quality. Safety standards become one of the most important technical standards.

Electrical safety performance test mainly has withstanding voltage test, insulation resistance test, leakage current test and grounding resistance test. Brief introduction:

1. Withstanding voltage test is one of the main methods to inspect the withstand voltage capacity of electrical appliances, electrical equipment, electrical wiring and electrical safety appliance. It has power frequency withstand voltage test and DC withstand voltage test.  The test voltage of power frequency withstand voltage test is one time or several times than the tested voltage, it will not be lower than 1000V. The test time: it is 1 minute for porcelain and liquid as the main insulation equipment; it is 5 minutes for the organic solids as the main insulation equipment; it is 3 minutes for voltage transformer; it is 10 minutes for oil immersed power cable. It can find local defects, moisture and aging of insulation if electrical equipment does withstand voltage test. AC withstand voltage test: Do the test voltage in 2.5 times or above of the tested equipment voltage, it starts from the point of dielectric loss’s thermal breakdown, it can effectively find the weakness of local free and insulation aging. Due to the voltage is mainly divided by capacitive in AC voltage; it can effectively expose the defects of equipment insulation.

It is mainly to achieve the following purposes:
i. Detect insulation withstand voltage capacity from working voltage or overvoltage capacity.
ii. Check the insulation of electric equipment manufacture or inspect quality.
iii. Exclude the insulation damage because of raw material, processing or transport; reduce the product early failure rate.

iv. Detect the electric clearance and creep age distances of insulation.

2 The insulation resistance index of electrical equipment and electrical circuit. Insulation resistance refers to the resistance between the two separated conductors by insulating material. In order to ensure the safety of the electric equipment operation, it should propose a minimum requirement for the polarity between the conductive body or the insulation resistance between the conductive body and the shell.

By measuring insulation resistance of electrical equipment, it can achieve the purchase as follows:

a. Learn the insulation performance of the insulation structure. Reasonable insulation structure (or insulation system) composed of high quality insulation material should have good insulation performance and high insulation resistance.
b. Learn the insulation processing quality of the electrical products. The insulation treatment of electrical equipment is poor; its insulation performance will be obviously decreased.
c. Learn the insulation damp and polluted situation, when the insulation of the electrical equipment is damp and polluted the insulation resistance is usually decreased obviously.

d. Inspect whether the insulation can withstand the withstand voltage test. When do the withstand voltage test, if the insulation resistance of electrical equipment is lower than a certain value, it will produce large test current, which leads to thermal breakdown and damage the insulation of electrical equipment. Therefore, it is usually to measure the insulation resistance before the withstand voltage test in all kinds of test standards.

3 Grounding resistance is the resistance when the current flows from the grounding device into earth, then through another grounding body or the resistant that encountered when spread to distant. It includes the resistance between the ground wire and the grounding body, the contact resistant between the grounding body and the earth and the earth resistance between two ground bodies or the earth resistance between the grounding body and infinity. The grounding resistance directly reflects the contact degree between electrical device and earth, also reflects the grounding grid scale.

4 Leakage current is the current through its surrounding medium or insulation surface between the metal parts in electrical equipment.

Lisun Group’s LS9934 Automatic Safety Test System is widely applied to Luminaries manufacturing enterprise and lab, such as Saudi Lighting Co. Ltd. (SAUDI ARABIA), Institute for Optical Sciences (Canada), PT. SHARP SEMICONDUCTOR INDONESIA (Indonesia), TUV Rheinland InterCert Kft. (Hungary), Institute of Testing and Certification India Pvt. Ltd (India) etc. The reason why Lisun can win some many customers is because we always practice the motto of right products, right price and right service. Lisun will continue feedback good quality products and superior service in the feature.