Again, the voltage to the ground in the ungrounded conductors does not exceed 150 V. Figure 2. Single-phase, 3-wire, 480-240/120 V transformer. Image used courtesy of Lorenzo Mari This system is typical in residential and office services requiring 120 V outlets. In a 3-phase, 4-wire,...
250.122 (B) Increased in Size – Where ungrounded conductors are increased in size, equipment grounding conductors, where installed, shall be increased in size proportionately according to circular mil area of the ungrounded conductors. Equipment grounding conductors on the load side of the service dis...
standard socket configuration that includes a slot for a center-line, rounded pin connected to a safety ground to facilitate the ground and two blade-shaped slots of uniform but differing sizes to prevent ungrounded (two-wire) devices from being incorrectly connected. Additionally, the NEC requires...
332-DLT621-1997-交流电器装置的接地标准-Grounding for AC electrical installations-en-全文.pdf,The Power Industry Standard of PRC DL/T 621-1997 交流电气装置的接地 Grounding for AC electrical installations Approved on 1997-09-02 Implemented on 1998-01-01 Ap
National Electrical Code Section 250.140 Frames of Ranges and Clothes Dryers Connect the frames of electric ranges, counter-mounted cooking units, wall-mounted ovens, clothes dryers, and junction boxes or outlets that belong to the circuit for these appliances to the equipment grounding conduc...
electrical device. For example, if the ungrounded conductor (known as the hot conductor) were to come into contact with a metallic case of a tool the equipment grounding conductor would provide the return path to the source of the electricity, cause a large current flow (it would be a ...