The so-called zero line electrification refers to the potential difference between the zero line and the earth. The zero line of the diesel generator is electrified, which means that it is not well grounded. If it is well grounded, the current will flow into the ground, and it will not be detected by the electric pen. If the neutral wire is detected to be charged with an electric pen, either the neutral wire is broken or the contact is not good. In fact, the neutral line is electrified, which is obviously a kind of fault. Since the diesel generator room usually adopts the precautionary measures of flat iron grounding, even if the neutral line is powered, it will not cause electric shock. But this is not the correct way to deal with the electrification of the neutral line. We must find out the cause of the electrification of the neutral line, and then carry out corresponding technical treatment.