Ask the great gods about household electricity! ! ! The phenomenon is very strange. I ask for your help!

1, determine the leakage or short circuit:

When the load is fully loaded or partially loaded, when the switch is closed, it is a short circuit when the current is large, and it is a leakage when the current is small. If there is no instrument for measuring current (clamp ammeter), disconnect the live wire under the leakage circuit breaker and connect it in series with a small broken wire or a 220V bulb. It is normal for small wires not to burn out or for light bulbs to light normally and not to trip. If the small wire is not burnt out or the light bulb is lit normally, tripping is leakage; Small wires or bulbs are short-circuited.

2, leakage or short circuit range:

Disconnect all loads (electrical appliances) except electric lights, and check by 1. If the fault still exists, it means that the fault occurred in the line. If the fault disappears, it means that the fault point occurred in the electrical equipment.

If the fault point occurs on electrical equipment, it will be easier. Put all kinds of electrical equipment in, and you will know that there is something wrong with the electrical equipment if it goes wrong.

If the fault occurs in the line, it should be divided into several parts according to the direction and convenience of the line, and the fault range should be narrowed by disconnection or connection inspection respectively.

Inspection method 2:

1, under the condition of no switch, use a 500V shaking table to measure the resistance between live wire and zero wire to ground. More than 0.5 megohm is qualified, zero megohm is grounded, and 0. 1-0.4 megohm is unqualified, but it can be used.

2. In the absence of switch, disconnect all loads (remove the plug controlled by plug and disconnect the switch controlled by switch), and measure the resistance between live wire and neutral wire with a 500V shaking table. More than 0.5 megohm is qualified, zero ohm short circuit, 0. 1-0.4 is unqualified, but it will not short circuit and can be used. In the case of zero line, it may be that the live wire and the zero line meet together, or it may be that both the live wire and the zero line are grounded.

It is meaningless to find the electrician installed at that time. After a long time, I must have forgotten that the electrician is installing every day, so I can still remember.

There are many kinds of inspection methods. Ordinary electricians can't solve such a fault. With good technical quality, they will use optimization methods to quickly compress the fault range, determine the fault point or remove the fault point, and supply power to the recovery without problems.

Trouble-prone places:

1, if your circuit installation quality is poor and there is a connector in the middle of the dark wire (violation), it may be a short circuit or grounding of the connector; 2. If your circuit conductor configuration is low, the cross-sectional area is small, the conductor often heats up and the insulation is reduced, which will lead to short circuit or leakage; 3. Sockets in wet places, sockets with large capacity, and contacts are prone to heating and disconnection, resulting in short circuit or leakage accidents; 4, other installation hazards, etc.