Should both the motor bracket and the enclosure be grounded for protection?
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Should both the motor bracket and the enclosure be grounded for protection? If the two are welded together and one of them is grounded, is that enough?
I guess they’re all needed; it’s better to have them than not
What if it’s only the bracket that is grounded?
If welded together, one ground connection is sufficient
According to clause 5.5.3 of the \"GB 50058-2014 Code for Design of Electrical Installations in Explosive Atmospheres\", for this marine user, 1) it refers to the normally uncharged metal enclosure of equipment with an AC rated voltage of 1000 V or less and a DC rated voltage of 1500 V or less, when located on a surface with poor electrical conductivity. 2) The normally de-energized metal enclosure of equipment in a dry environment, with an AC rated voltage of 127 V or less and a DC voltage of 110 V or less ； 3) Equipment installed on a grounded metal structure. The above three devices still need to be grounded. The specifications clearly state that it refers to the equipment enclosure, not the equipment bracket. Therefore, proper construction requires that the equipment enclosure be directly grounded (the ground wire must be connected to the grounding terminal on the motor enclosure), rather than using a bracket for grounding. It prevents accidental electric shock incidents to people caused by electrical leakage from the motor, which can occur when there is poor contact between the bracket and the motor housing.