Regarding the issue of motor grounding and neutral connection in three-phase four-wire systems
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Recently, experts visited our factory for an inspection and pointed out that our motors were not grounded. We use a three-phase four-wire system; one of the wires in the terminal box is already connected to the enclosure. Is it appropriate to connect another ground wire as well? Are there any detailed regulations regarding this? . . . Please ask an expert to help answer
It is recommended to take photos of the internal grounding situation; a description of the current grounding setup will suffice. Our workshop has also encountered this problem; experts require an obvious externally exposed grounding connection.
You may refer to GB 50169-2016 \"Code for Construction and Acceptance of Grounding Installations in Electrical Installation Projects\"
Protective grounding must be implemented now, covering on-site explosion-proof maintenance boxes, metal switches, etc.
A motor is a high-power electrical device, not a low-power meter. This post should be moved to the electrical section so that the experts there can answer it. .
In a TNS system, the neutral wire is not the ground wire. A TNS system is a 5-wire system, consisting of three live wires, one neutral wire, and one ground wire.
It seems that it was indeed posted in the wrong forum. I can’t move it myself; could an administrator help with that? We are currently using three-phase asynchronous motors, and we operate under a TN-C system. The motor’s terminal box also has four terminals: three for the live wires and one for the protective wire. I’m not sure how to connect this motor using a three-phase five-wire system. .
It seems that it was indeed posted in the wrong forum. I can’t move it myself; could an administrator help with that? We are currently using three-phase asynchronous motors, and we operate under a TN-C system. The motor’s terminal box also has four terminals: three for the live wires and one for the protective wire. I’m not sure how to connect this motor using a three-phase five-wire system. .
Class A processes must use a TN-S system.
Is the casing not grounded? He surely won’t open your junction box to check the wires inside, right?
Is the casing not grounded? He surely won’t open your junction box to check the wires inside, right?