Grounding protection for civil equipment
Thread Content
The company canteen uses a noodle rolling machine. Yesterday, an employee in the canteen suffered burns to their hand due to a short circuit that occurred when they unplugged the device; this equipment does not have a leakage protector installed. Now a leakage protector needs to be installed, but since the socket is three-phase, it is not possible to connect a neutral wire. What should be done?
Since your equipment uses a three-phase power supply, in the event of a three-phase short circuit or a two-phase short circuit, the leakage protector will not be able to provide protection; it is therefore more reliable to install an overcurrent protector as well. The equipment enclosure must be safely grounded. I think the neutral wire of a circuit breaker can be replaced with a ground wire.
There are four-pole leakage protectors, and a neutral wire must be used; the exposed metal parts of the pasta press mechanism must be connected to the neutral wire. Also, the leakage protector must be installed one stage before the socket.
The short circuit mentioned by the poster is a circuit short circuit, not a leakage fault; installing a miniature circuit breaker in front of the socket should solve the problem； If it is necessary to prevent leakage faults, a leakage circuit breaker must be installed. This type of circuit breaker provides protection against both short circuits and electrical leaks. For grounding protection, the system uses protective zero wiring: the socket is removed, and the power cable is connected directly; the neutral wire is connected to the device’s casing, with the leakage circuit breaker used to control the power supply to the device.