NEC 625 covers details about Electric Vehicle Charging Systems. This (Article 625) is intended to cover details of Electric Vehicle (EV) electrical systems providing power supply by both inductive or conductive means to the electrical vehicle including all electrical wiring and equipment installed between the service port and skin of the automotive type electric vehicle
NEC 625.4 specifies the voltages (the nominal a.c voltage) 120, 120/240, 208Y/120, 240, 480Y/277, 480, 600Y/347, and 600V that can be provided to supply power to EV.
NEC 625.9 covers the wiring methods of electric vehicle charging systems. The electric vehicle coupler (a mating electric vehicle inlet & electric vehicle connector set) shall be polarized. It has to be configurated to be non-interchangeable with wiring devices in other electrical systems. Electric vehicle couplers which are non-grounding type shall not be interchangeable with grounding type EV couplers. EV couplers must provide a safe interface for the operating person during connecting to the vehicle or disconnecting the vehicle from the charging system. The operating person will not typically have knowledge of the equipment operation and associated hazards. EV coupler is provided with means to avoid any unintentional disconnection. EV coupler shall be provided with a grounding pole unless part of the system is identified and listed for the purpose (NEC 250). In case of EV coupler is provided with a ground pole, it is to be designed so that the grounding pole connection is first made while connecting and last to break contact while disconnecting.
NEC 625.13 covers details about EV supply equipment. EV supply equipment rated 125V, single phase, 15 or 20 A is permitted to supply EV charging loads. For rating purposes, EV charging loads are considered continuous loads. EV supply equipment shall be marked as whether Ventilation is required or not. Also, electrical vehicle supply equipment means of coupling to the EV either inductive or conductive shall be listed and labeled for the purpose (NEC 625.16). NEC 625.17 specifies that EV supply equipment cable shall be Type EV, EVJ, EVE, EVJE, EVT, or EVJT flexible cable as given in Article 400 and Table 400.4. Cable ampacities shall be as per Table 400.5(A)(1) & Table 400.5(A)(2). EV equipment cable length shall be limited to 7.5mts (25 ft). A cable length greater than 25 ft is permitted where it is provided with a cable management system for charging commercial parking areas.
NEC 625.18 covers the requirement for interlock provision which de-energizes the EV connector and cable in case the EV connector is disconnected from EV. In case the portable cord & plug-connected supply equipment intends to connect to receptacle outlets rated at 125 V, 1-phase, 15, and 20 A interlock provision is not required. NEC 625.19 requires the provision of automatic means to de-energize the cable conductors and EV connector in case of any strain which could result in either cable rupture or separation of cable from the electric connector exposing the live parts. This provision is not required for portable cord & plug connected equipment connecting to receptacle outlets rated at 125 V, single phase 15 and 20A.
NEC 625.21 covers details about overcurrent protection details provision for feeders and branch circuits which are supplying power to EV supply equipment. These branch circuits & feeders are sized for continuous duty and shall be rated not less than 125% load of maximum EV supply equipment. In case of any noncontinuous load is also connected to the same feeder or branch circuits, then the overcurrent protection device shall be rated not less than the sum of 100% non-continuous load plus 125% of continuous load.
NEC 625.22 requires that in the case of cord and plug-connected EV supply equipment is used, interrupting device listed for the personnel protection system shall be an integral part of the attachment plug or located in the EV power supply equipment cable not more than 300 mm (12 inches) from attachment plug. NEC 625.23 requires that disconnecting means shall be installed in a readily accessible location for EV power supply equipment rated more than 60 A or more than 150 V to ground. NEC 625.25 requires that in case of loss of power supply (voltage) from the utility or other electrical system(s), power shall not be back-fed from EV & supply equipment to the wiring system of premises unless it is permitted and listed as suitable for that purpose (bi-directional power feed).
NEC 625.28 permits the installation of Electric Vehicle charging equipment in hazardous locations in accordance with the requirements given in Article 500 through 516 shall be applied for installation.
NEC 625.29 provides details about EV supply equipment installation requirements at Indoor sites. EV supply equipment is permitted to have a direct connection to the electric vehicle at indoor sites. The height at which EV supply equipment is stored or located is shall not be less than 450 mm (18 inches) and shall not be more than 1.2 meters (4 ft) above the floor level. In the case of electric vehicles provided with non-vented storage batteries for energy storage ( do not emit hydrogen gas while charging which may lead to explosion) are used or where EV supply equipment is listed or labeled and is suitable for EV charging without any ventilation requirement, provision for any mechanical or passive ventilation shall not be required. If EV charging equipment is listed or labeled as suitable for EV charging with ventilation requirements, mechanical ventilation systems such as fans and blowers are to be provided. The ventilation system shall require permanent installation for provision for air intake from outdoors & exhaust outdoors respectively. A building or structure shall be permitted to have positive-pressure ventilation systems if it is specially designed and approved for the application.
NEC 625.30 covers details related to requirements for EV supply equipment installation in Outdoor sites. Similar to the Indoor site requirements, EV supply equipment is permitted to have a direct connection to the electric vehicle which has to be charged. The EV supply equipment coupling means shall be stored or located at a height minimum of 600mm (24 inches) and not more than 1.2 metre ( 4 feet) above the parking surface.