What is the principle of the leakage switch and the precautions when installing?

The principle of action of the leakage protection switch is: there are two groups on an iron core: an input current winding and an output current winding, when there is no leakage, the input current and the output current are equal, and the vector sum of the two magnetic fluxes on the iron core is zero, and the electric potential will not be induced on the third winding, otherwise the voltage will be induced on the third winding, and the actuator will be driven by amplification, so that the switch trips.

In front of the above-mentioned UPS, add a leakage protection switch, although the UPS has no leakage, but because the magnetic flux vector formed by each harmonic in the core and due to the hysteresis of the core can not be zero, so there is an illusion similar to leakage, so that the leakage protector trips frequently.

The leakage wire passes the live wire neutral wire through an O-shaped magnetic ring as the primary at the same time, and the secondary uses the N-turn output to push an electromagnetic mechanism, and the electromagnetic mechanism trips when it acts. The principle is that under normal circumstances, the current flow in and out of the live wire and the neutral line is equal to the outflow, so the secondary voltage induced is also zero, when the live wire or the neutral wire has a wire to the ground with grounding resistance or short circuit, then the voltage difference between the current on the live wire and the neutral line appears, through the secondary induction, when a certain difference is reached, the electromagnetic mechanism is pushed to disconnect from the main circuit. At present, there are two main types: electronic and electromagnetic.

An air switch is a type of switch that trips as long as there is a short circuit and the switch forms a loop.

There are three types of tripping methods: thermal, electromagnetic and duplex.

When the general overload occurs in the line, although the overload current can not make the electromagnetic tripper move, it can make the thermal element generate a certain amount of heat, promote the bimetal sheet to bend upwards when heated, push the lever to disconnect the hook and the lock, break the main contact, and cut off the power supply.

When the line is short-circuited or seriously overloaded, the short-circuit current exceeds the instantaneous tripping setting current value, and the electromagnetic tripper generates a large enough suction force to suck the armature and hit the lever, so that the hook rotates upward around the shaft seat and disengages the lock, and the lock breaks the three main contacts under the action of the reaction spring to cut off the power supply.

The tripping mechanism of the switch is a set of connecting rod devices. When the main contact is closed by the operating mechanism, it is locked in the closing position by the latch. If a fault occurs in the circuit, the relevant tripper will act to disengage the locking hook in the trip mechanism, so that the main contact is quickly disconnected by the release spring.

According to the different protection functions, the tripper can be divided into overcurrent trippers and loss-of-voltage trippers.

Under normal conditions, the armature of the overcurrent tripper is released; In the event of a serious overload or short circuit fault, the coil connected in series with the main circuit will generate a strong electromagnetic attraction to attract the street railway down and jack the lock hook, so that the main contact is disconnected. The undervoltage tripper works on the contrary, when the voltage is normal, the electromagnetic suction pulls the armature and the main contact is closed. In the event of a severe voltage drop or power failure, the armature is released and the main contact is disconnected.

When the power supply voltage returns to normal, it must be re-closed before it can work, and the voltage loss protection is realized.

Because there are many ways of insulation, there are oil switches, vacuum switches and other inert gas (sulfur hexafluoride gas) switches. An air switch is a switch that uses air arc extinguishing, so it is called an air switch. Air is used to extinguish the arc generated during the switching process.

That's why it's called an air switch.

The leakage switch is generally installed at the inlet end of the user's power supply.

The rated current of the leakage protector for household lighting electricity is generally selected according to the size of the electricity consumption: 16A, 32AA, 100A, etc. There is a leakage test button on the leakage switch; Generally, I try it once a month; If you press it once, it will automatically trip, which means that the leakage protection is normal.

Leakage switch, a kind of switch, is mainly used to prevent the occurrence of leakage accidents, and the principle of action of the switch is: there are two windings on an iron core, the main winding and the secondary winding. The main winding also has two windings:

They are the input current winding and the output current winding. When there is no leakage, the input current and the output current are equal, and the vector sum of the two magnetic fluxes on the iron core is zero, and the electric potential will not be induced on the secondary winding, otherwise the voltage will be induced on the secondary winding, and the actuator will be pushed by the amplifier to trip the switch.

The leakage protector is commonly known as "leakage protection" and is installed in the low-voltage circuit of the main electrical box. When leakage and electric shock accidents occur and the current reaches a certain value, the protector will automatically disconnect the power supply within a limited time to prevent leakage from endangering safety. For the sake of safety, every household should be equipped with a "leak insurance".

During the installation process, the following aspects should be noted:

1. Regular products certified by the state should be purchased.

2. Please have a qualified electrician for installation.

3. After the installation is completed, the test jump should be checked three times, and the action should be correct.

4. The household leakage protector should be tested every month to check whether it is normal.

5. When the leakage protector trips, it can be sent once, if the test delivery fails, the cause of the fault should be investigated in time.

6. When the leakage protector frequently jumps, a qualified electrician must be asked to help find out the problem.

The leakage protection function of the main switch can be removed. But those switches generally don't do much protection. It is recommended to use a leak warranty with multiple functions.

You can consider turning off the leakage or setting it larger. Some have over-voltage and under-voltage protection, zero line protection, and some also have automatic reclosing function. It's safe to use, and it's much more worry-free.

Remove the leakage protection of the main switch and add leakage protection to the three branch switches, there is no problem. It is usually used to set up leakage protection on the main switch to prevent fire caused by grounding fault.