Exam questions, seeking help from everyone

Welding machines need to be connected to a leakage protector; according to relevant regulations, hand tools and portable electrical devices also require such protection. Since the internal components of a welding machine can be damaged, resulting in a risk of electric leakage, it is necessary to install a leakage protector on the welding machine for safety reasons. The welding machine should be connected to a dedicated circuit breaker. When connecting it, the wires of the welding machine must be attached to the appropriate terminals on the circuit breaker as required; the wires must not be connected incorrectly, otherwise issues such as the circuit breaker tripping may occur. :lol

Refer to the analysis of the reasons for frequent tripping of leakage protectors at construction sites: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=42271&shareuid=301199. The temporary electrical installations at construction sites do not meet regulatory requirements, and the measures related to leakage protection, grounding, and neutral connection for electrical equipment are inadequate. The cables used are damaged, and the connections are not properly handled, which can easily lead to electric shock accidents.

Ahaha, let me explain this sea friend to you! There are generally the following situations in which a welding machine leaks electricity: The wiring of the welding machine comes into contact with its casing, causing electricity to leak from the machine ； Welding machines experience insulation damage due to excessive use, prolonged operation, or frequent overloading; the damaged wires come into contact with the casing, resulting in electrical leakage ； The power cords of transformers, reactors, electric fans, or other electrical equipment were connected to the welding machine, resulting in leakage current from the welding machine’s casing ； Before using a welding machine, the absence of a ground wire or poor contact can also lead to leakage current from the welding machine ； Improper installation of power cords—such as loose fixation of the cords or excessively long wire lengths left for connecting the power switch—can result in contact with the machine casing, thereby causing electrical leakage from the welding machine’s casing. Therefore, in light of all the above situations, it is best to use a leakage protector when operating a welding machine to prevent injury to people! Additionally, it is also what the standards recommend using! As specified in clause 9.4.6 of the standard GB 50194-2014 \"Code for Safety of Power Supply and Use at Construction Sites\", when using AC welding machines at construction sites, it is advisable to install electric shock protection devices.