Leakage current is often mentioned in safety standards. Xingyuan to some sort of explanation. For a grounded product (Class I), the leakage Current is the current that flows through the Earthing Conductor when the meter is operating normally. In the case of an ungrounded product (Class II) or a Class I product with a ground fault, this leakage Current represents the Touch Current flowing through the human body when the human body touches the product. -- -- -- < strong > < a href = "http://www.globalgd.com/" > ce certification body < / a > < / strong > < / div >
Impedance of the human body
In the older safety standards, for the convenience of measurement, the impedance of the human body can often be a 1500ohm resistor in parallel with a 0.15μ F capacitance to simulate. Of course, the human body impedance varies from person to person, in general, fat people are more conductive than thin people, and the thickness of the skin and dry humidity, and the contact area is the palm or the back of the hand, so that the human body will feel different for the current.
Touch Current
In the definition of the IEC 60990 standard, the so-called contact current is the current that flows through the human body when the human body comes into contact with the product in the case of normal or single part failure. The so-called failure of a single part can be considered as missing the ground wire, or the case of Line and Neutral reverse connection. IEC 60990 does not need to consider that the unconnected ground wire is simultaneously in Line and Neutral reverse connection, so this case is two abnormal conditions at the same time. However, this situation can occur in old houses in North America!
According to research, different levels of low-frequency current flowing through the human body may cause different results as follows:
Current grade Current size (mA)
Have a Perception of 0.5mA
Electrokinetic Reaction (Reaction) 3.5mA
The Inability to Let Go 10 mA
Electric Burns 70 mA
Influence of different frequency current on human body
The effect of high frequency current on the human body is less than that of low frequency current (such as 60Hz). According to ANSI standard C101, the maximum allowable contact current for high frequency currents is allowed up to 70mA. In order to simulate the impact of currents at different frequencies on the human body, IEC 60990 and ANSI standard C101 provide a frequency compensation line, which can automatically calculate the impact of currents at different frequencies on the human body.
