Why do voltage withstand, grounding, leakage current test?
Voltage withstand: to do insulation distance measurement confirmation
Grounding: to determine the grounding circuit impedance is relatively smaller than the human body impedance model. If there is a leakage, the shunt from the human body will be small enough not to make the ventricles confess.
Leakage current: whether the current from the electrical circuit or alternating current to a live body is large enough to electrocute a person Grounding tests must be performed on all Class 1 products. The purpose of the test is to ensure that all electrically conductive parts of the product that would become energized in the event of a single insulation failure and that can be touched by the user are reliably connected to the power input ground point. In other words, a ground test uses a high-current, low-voltage source applied to the ground loop to verify the integrity of the ground path.
Compliance is determined by measuring the impedance connected between the protective grounding connection terminal or ground contact and the part, which is considered compliant if the impedance does not exceed a certain value determined by the product safety standard. It is important to remember that from a structural and design point of view, the conductor used for protective earthing should not contain any switches or fuses.
Some standards, including IEC60950-I, name the leakage current (Leakage Current) as the contact current (Touch Current). That is, the current that flows through a human or animal body when it comes into contact with an accessible part of the equipment. There is another concept, the "protective conductor current", which is equivalent to the current flowing through the protective conductor. Therefore, the protective conductor current is never the cause of an electric shock because, by definition, the protective conductor is connected to the earth at all times.
The dielectric strength test, also known as the hipot test, is probably the most widely known and frequently performed production line safety test. In fact, demonstrating its importance is part of every standard. hipot testing is a non-destructive test that determines the adequacy of electrical insulation to resist instantaneous high voltages. It is a high voltage test applied to all equipment to ensure that the insulation is adequate. Other reasons for performing the hipot test are that it identifies possible defects such as insufficient leakage distances and electrical clearances caused during the manufacturing process.