The basic introduction of RCCB
1.What is RCCB?
A: RCCB is an electrical safety device. The RCCB is installed in the low-voltage circuit, in the event of leakage and electric shock, and to protect the action of the current limit value, it immediately within a limited time action automatically disconnect the power supply for protection.
A: The RCCB is mainly composed of three parts: detection components, the middle part of the amplification, the operating actuator.
① test components. Composed of zero-sequence transformers, detecting leakage currents and signaling.
② enlarge link. The weak leakage signal amplification, according to different devices (amplification components can be used mechanical or electronic devices) constitute the electromagnetic protector phase electronic protector.
③ implementing agencies. Upon receipt of the signal, the main switch is switched from the closed position to the off position, thereby shutting off the power source, which is the tripped part of the protected circuit from the grid.
3.which are the main technical parameters of RCCB？
A: The main action performance parameters are: rated leakage action current, rated leakage action time, rated leakage current does not act. Other parameters are: power frequency, rated voltage, rated current.
① rated leakage operating current under the conditions specified, so that leakage current protection device. For example, 30mA protector, when the access current value reaches 30mA, the protector that action disconnect the power.
② rated leakage action time refers to the sudden application of rated leakage action current, to the protection circuit is cut off until the time. For example, 30mA × 0.1s protector, from the current value reaches 30mA, the main contact separation time of not more than 0.1s.
③ rated leakage current does not act under the conditions specified, the leakage current protection device does not act, generally should choose the leakage current value of the current one-half. For example, the leakage current of 30mA RCCB, the current value reaches 15mA below, the protection should not act, otherwise the sensitivity is too high, easy to malfunction, affecting the normal operation of electrical equipment.
④ other parameters such as: power frequency, rated voltage, rated current, etc., the selection of leakage protector should be used with the line and electrical equipment to adapt. RCCB operating voltage to adapt to fluctuations in the normal power grid rated voltage, if the fluctuations are too large, will affect the normal operation of the protector, especially electronic products, power supply voltage is lower than the rated voltage protection device will refuse to operate. RCCB rated current, but also with the loop in the actual current, if the actual operating current is greater than the rated current of the protector, causing overload and make the protector malfunction
4.whatis the main protective effect of RCCB?
A: The RCCB is mainly to provide indirect contact protection, under certain conditions, can also be used as a supplementary protection of direct contact, the protection of potentially fatal electric shock accidents.
5.What is direct contact and indirect contact protection?
A: When the body contacts the charged body current through the human body, it is called the human body electric shock. In accordance with the reasons for the human body can be divided into direct electric shock and indirect electric shock.
Direct electric shock, refers to the body directly touches the charged body (such as touching the phase), resulting in electric shock. Indirect contact, refers to the body touches under normal circumstances without electricity, fault conditions charged metal conductor (such as touch leakage shell), resulting in electric shock. According to the reasons for the different electric shocks, the electric shock prevention measures taken are also divided into: direct contact with the protection of indirect contact protection. Direct contact protection can generally use insulation, protective cover, fence, safety distance and other measures; indirect contact protection can be used to protect the ground (zero), cut off protection, leakage protection and other measures.
6.Which electrical equipment need to install RCCB?
A: The Technical Specifications for Temporary Electricity Consumption at Construction Site stipulates that “all the electric equipment at the construction site shall be provided with a leakage protection device at the head end of the equipment load line, except for the protection of zero.”
The above provisions talked about the three Aspects:
① All the electrical equipment at the construction site should be equipped with RCCB. Because of the open-air construction, wet environment and changing personnel, coupled with the weakness of equipment management, it is dangerous to use electricity and requires all electrical equipment including power and lighting equipment, mobile and fixed equipment. Of course, this does not include equipment powered by safety voltage and isolation transformers.
② The original protection according to the provisions of zero (grounding) measures are still required as required, which is safe power of the most basic technical measures can’t be removed.
③ RCCB installed in the first end of the load line of electrical equipment. The purpose of doing so, the protection of electrical equipment, but also on the load line protection to prevent damage due to line insulation caused by electric shock accident.