What happens if the air conditioner power cord has no ground wire?

●Why does the air conditioner need a ground wire?

Everyone knows that the air conditioner power cord needs to be grounded. What happens if there is no ground wire? The following is a message from an after-sales brother.

That's right, when the inverter air conditioner is not grounded, the outdoor unit is energized. So, why does the air conditioner need to be grounded? Why is the outer shell energized? What should I do when there is no ground wire?

1. Why does the air conditioner need to be wired?

1. The national standard GB4706.1 stipulates that air conditioners are Class I appliances, and the power cord must have a ground wire, and the metal casing must be connected to the ground wire. Simply put, this is a national safety regulation, otherwise it will not be possible to obtain 3C certification and enter the market.

2. The grounding device can provide good protection for the safety of people and equipment. When the human body touches the electrical equipment whose shell is energized, since the contact resistance of the grounding body is much smaller than the resistance of the human body, most of the current enters the earth through the grounding body, and only a small part flows through the human body, which will not cause harm to human life, thus ensuring the personal safety of the user.

2. Why is the inverter air conditioner energized when the ungrounded wire is not connected?

1. Since there is a Y capacitor (safety capacitor) in the inverter air conditioner circuit, that is, L-PE or N-PE has capacitive coupling, the ground wire is used as a path to absorb high-frequency interference. Based on the limitation of leakage current, the value of the Y capacitor cannot be too large. Generally, the Y capacitor is nF level, which is used to suppress common mode interference. Therefore, the leakage current of electrical appliances with Y capacitors is generally below 1 mA.

2. Since the capacitance of the Y capacitor is small, only high-frequency signals (interference noise) can pass through, so it is not 50Hz AC power. It is similar to static electricity, with the characteristics of high voltage and short time T.

3. What if there is no ground wire in the user’s home?

1. The grounding rod can be made by yourself. You can choose round steel with diameter of Φ18mm or above, 60cm long, with a point at one end and a hole of Φ6mm at the other end. When connecting the wire, you can use screws to crimp it, and weld a 20cm long round steel horizontally at the hole end to facilitate insertion and removal. The connecting wire can use a slightly thicker multi-strand insulated soft copper wire, crimp a lug at one end, and screw it on the homemade grounding rod.

Make a simple test ground wire according to the above method. The user can compare the data of the front and rear shell charges on site. Let the facts speak for themselves. After the user approves, ask a professional electrician to install the ground wire.

2. (For those with electrician qualifications) Self-made grounding bodies are made of galvanized steel pipes or angle steels. The diameter of the steel pipe is 50mm, the wall thickness is not less than 3.5mm, and the length is 2~3m. The angle steel is 50mm×50mm×5mm and the length is 2~3m. After the grounding body is made, it is driven vertically into the ground. The grounding body and the grounding of the socket are connected through the grounding wire or directly connected to the housing of the equipment. After

the grounding body is connected, the grounding resistance telemetry should be carried out. The grounding resistance of the grounding device should be measured using a grounding resistance meter. The grounding resistance of the household grounding device can be magnified to 10 ohms. The grounding wire must be connected reliably and reach the specified cross-sectional area and meet the design or specification requirements. At the same time, it should be noted that the grounding wire must not be directly connected to the metal pipeline of coal gas or natural gas.

3. Installing a leakage protector is also a good protection method. In the event of an accident, the leakage protection device will automatically cut off the power supply and play a protective role. At the same time, it can also keep the grounded metal casing of the electrical appliance at zero potential with the ground to avoid harm to the human body.