The first thing to do is to cut off the power. Before the power is cut off, the ignition switch should be turned off. At the same time, the electrical equipment, such as audio equipment, should be turned off. The specific power-off sequence is as follows: safety first, so in maintenance, first pull out the negative pole, and then pull out the positive pole. When installing, the sequence is the opposite, first install the positive pole, then install the negative pole. Some friends will ask: why cut off the negative pole first? Here, I'd like to explain to you:
1. First remove the positive electrode, there is a risk of burning out the electrical components, which is easy to cause the loss of computer board. In the actual maintenance process of the circuit, there are many people who damage the circuit and burn the handle because of violating the operation rules. Because the short-circuit current of the positive and negative electrodes of the battery is very large, it can produce high temperature instantly.
2. If the positive pole is pulled out first, because the negative pole is grounded, that is, the metal body around the positive pole is all negative pole. If the tool touches the metal body beside the positive electrode when removing the positive connection with a tool, it will cause a short circuit between the positive and negative poles of the battery.
3. If you pull out the negative pole first, because the metal body around the negative pole is connected with the negative pole, even if the tool touches it, it will not produce any bad results. When the negative pole is pulled out and the power has been cut off, it will not be dangerous to pull the positive pole again.
Here we should pay attention to one point: the battery of the current mixer truck is equipped with a master switch, but the original one is not available, so it is not easy to operate; moreover, if it is a dangerous goods transport vehicle, such as an oil tank vehicle, the vehicle's tachograph is not allowed to be powered off. After the power failure, the vehicle owner may have to bear legal responsibility, but I think if it is dangerous goods transportation A backup power supply for the tachograph can be placed on the car, so that even if the circuit fails, the tachograph will not be cut off. If your mixer circuit problems, must pay attention to the above problems Oh!