with the upcoming need of high-power-charging, 3-phase power is already available in America and will be offered to all customers. the three phase, 4 wire, 480 wye/277 volts will be supported for the Model S. And this is 3-Phase
1. Single-phase, 120/240 volt service is limited to 50 kVA maximum where utilization equipment includes individual motors not over 6-1/2 HP. Self-contained meter socket applications are limited
to 72kW demand. 2. Where the present service is three phase, 4 wire, 208 wye/120 volts. Exception: In Network areas
where standard service voltage is three-phase, 4 wire, 208 wye/120 volts, demand for single-phase service 120/208 volts is not to exceed either (a) 60 kVA for the Upstate New York area or (b) 20 kVA for the areas in Massachusetts, New Hampshire, and Rhode Island.
3. Where the present service is three phase, 4 wire, 480 wye/277 volts. Three-phase, 4 wire, 480 wye/277 volts is Commercial and Industrial use only.
4. Where supplied by cluster mounted overhead transformers at the Company's discretion; see Section 9.2.1. Demand of 150kVA or more is generally preferred to be supplied by a pad mounted transformer service. Three-phase service normally will not be made available for a residence.
5. With the exception of network service, transformer vault services are limited to 1500 kVA at 480 wye/277 volts.
For both new applicants and existing customers, the Applicant or Customer shall submit a written request that includes its proposed in-service date, connected load, diversified demand, and load factor information. Refer to the “Process and Information” section at the beginning of this book. Customers having the potential to exceed 75 kVA of transformer capacity may be required to supply space for electrical equipment on private property in accordance with the Company’s Terms and Conditions; see Sections 4 and 9. Where three-phase secondary service is requested and available and the minimum Customer load is less than 50 kVA, the Customer may be required to contribute to the supply facilities’ installation cost according to the Company’s tariff in the specific service area.
3.7.2 New Customers (Applicants)
The delivery voltage for service to a new Customer is determined based on engineering considerations such as system loading, location of electric supplies, reliability, circuit protection and coordination, planning, operation and maintenance.
3.7.3 Existing Customers
3.7.3.1 Customer Expansion
The new delivery voltage for service to an existing Customer contemplating an expansion that will result in a maximum customer peak demand greater than the limit specified in Table 3.7.1-1, is determined based
38 For the latest authorized version, please refer to the company’s website at http://www.nationalgridus.com/electricalspecifications.
National Grid / Specification for Electrical Installations / April 2010
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