As we dinosaur fuel driving rednecks drive our fossil fueled antiques down the road to the service station, what risks are present well for most the high risk is fire! But what about electrical cars and the risks, on quick charge stations and is their grounding items or shock hazards or ARC FLASH risks!
Not to mention we the dinosaurs don’t see a LOT of filling stations for your new toy vehicles! An electric vehicle charging station, also called EV charging station, electric recharging point,charging point, charge point and EVSE (electric vehicle supply equipment), is an element in an infrastructure that supplies electric energy for the recharging of electric vehicles, such as plug-in electric vehicles, including electric cars, neighborhood electric vehicles and plug-in hybrids.
480V AC commercial 3 phase dedicated transformer converted to DC 500V (The closest thing to a gas station)
Fast charging stations can reduce charging times to less than one hour, but do not provide a full state of charge (80%). Batteries cannot be fully charged at that rapid pace. Just like charging an self-contained breathing apparatus cylinder quickly, batteries that are charged quickly do not reach a full state of charge because of heat buildup. Level 3 charging stations are a much more substantial and expensive installation, and are therefore only available on a commercial level. It should be noted that not all vehicles are compatible with a Level 3 charging station. Currently the Nissan Leaf and Tesla Model S have an option for a Level 3 charging connector.
All charging station installations above Level 1/mode 1 require electrical permits for installation in compliance with the National Electrical Code (NEC). NEC standards apply up to the point where the charging station is connected, but do not extend to the charging station itself.
Now that we have identified the types of charging stations, let us examine the types of potential dangers involved.
Automatic shut-off during drive-away event
Vehicles are designed to prevent “ignition on” while they are plugged in. It is therefore not possible to drive away from a charging station while plugged in.
Typical fuel hose break away (Toyota Prius)
Car-versus-charging station collision:
The charging station mounting pole in the ground could potentially be energized if it has been damaged. It could energize the vehicle, as well. This is no different than any other vehicle collision with an electronic device. Your goal as a first responder is to find out the ownership of the charging station and the location of the shut-off point for power. Depending on your local utility company, utilities are responsible only up to the point where the meter is installed. All components after the meter are considered consumer installed. A circuit breaker panel is required in each installation. Find out where the circuit breakers are, who owns them, and how to turn them off at the meter. Shut-off points could be inside structure, in a basement (if itâs a pre-1980 home), etc. Forced entry may be necessary for access to the shut-off point.
EV owners are using smartphone apps to find locations of commercial stations. You can find them the same way before they are an issue and scout them for power down. Contact the owner/business and see what is necessary for power-down access. If a power pole is an issue, (before the meter) you would call the utility for shut off. Grid shutdown may be necessary. Treat it like any other utility power concern. System equipment is designed with safety measures; your concern is power feed shutdown to the charging station.
Car fire while still plugged in (home charging station)
The charging system connector is designed to melt away and fall off from the vehicle (similar to a barbeque propane tank plastic connection melting and sealing the propane tank). Treat this situation as a normal house fire with consideration to utilities.
Car fire while still plugged in (commercial application):
Locate utility shut-off if possible. Handle vehicle fire appropriately.
Vandalism of public access station:
The charging station cord is not energized until a vehicle is plugged in. There will be no power on bare wires if a cord has been stolen by local copper “recyclers.”
Inductive charging (magnetic field induced battery charging) is being developed that would eliminate safety concerns such as vandalism/theft of copper wire and possible collision with the station. There would also be no wear-and-tear on plugs or charging cables. Inductive charging, however, has possible concerns regarding proximity to electrical fields. This type of charging is not yet in production.
As we have shown, the risks that are posed by EV charging stations are no greater than other electrical devices. Once a level of understanding is reached regarding the combination of transportation and the electric grid, procedures that are already in place can be used to mitigate dangers that may be encountered when responding to incidents regarding EV charging stations.Firefighters and tri service staff should know what they have in their area and find out how to power it down before they have an incident response.
EVs (all-electric vehicles) are powered only by one or more electric motors. They receive electricity by plugging into the grid and store it in batteries. They consume no petroleum-based fuel while driving and produce no tailpipe emissions. EVSE (electric vehicle supply equipment) delivers electrical energy from an electricity source to charge a PEV’s batteries. It communicates with the PEV to ensure that an appropriate and safe flow of electricity is supplied. EVSE units are commonly referred to as “charging stations.” HEVs (hybrid electric vehicles) combine an ICE or other propulsion source with batteries, regenerative braking, and an electric motor to provide high fuel economy. They rely on a petroleum-based or an alternative fuel for power and are not plugged in to charge. HEV batteries are charged by the ICE or other propulsion source and during regenerative braking. ICEs (internal combustion engines) generate mechanical power by burning a liquid fuel (such as gasoline, diesel, or biofuels) or a gaseous fuel (such as compressed natural gas). They are the dominant power source for on-road vehicles today. PEVs (plug-in electric vehicles) derive all or part of their power from electricity supplied by the electric grid. They include EVs and PHEVs. PHEVs (plug-in hybrid electric vehicles) use batteries to power an electric motor, plug into the electric grid to charge, and use a petroleum-based or an alternative fuel to power an ICE or other propulsion source.
The rate at which charging adds range to a PEV depends on the vehicle, the battery type, and the type of EVSE. The following are typical rates for a light-duty vehicle: Level 1: 2 to 5 miles of range per hour of charging Level 2: 10 to 20 miles of range per hour of charging DC fast charging: 60 to 80 miles of range in 20 minutes of charging.
As plug-in hybrid electric vehicles and battery electric vehicle ownership is expanding, there is a growing need for widely distributed publicly accessible charging stations, some of which support faster charging at higher voltages and currents than are available from residential EVSEs. Many charging stations are on-street facilities provided by electric utility companies or located at retail shopping centers and operated by many private companies. These charging stations provide one or a range of heavy duty or special connectors that conform to the variety of electric charging connector standards.
Although the rechargeable electric vehicles and equipment can be recharged from a domestic wall socket, a charging station is usually accessible to multiple electric vehicles and has additional current or connection sensing mechanisms to disconnect the power when the EV is not charging.
There are two main types of safety sensor:
· Current sensors which monitor the power consumed, and maintain the connection only if the demand is within a predetermined range. Sensor wires react more quickly, have fewer parts to fail and are possibly less expensive to design and implement. Current sensors however can use standard connectors and can readily provide an option for suppliers to monitor or charge for the electricity actually consumed.
· Additional physical “sensor wires” which provide a feedback signal such as specified by the undermentioned SAE J1772and IEC 62196 schemes that require special (multi-pin) power plug fittings.
In SAE terminology, 240 volt AC charging is known as Level 2 charging, and 500 volt DC high-current charging is known as DC Fast Charge. Owners can install a level 2 charging station at home, while businesses and local government provide level 2 and DC Fast Charge public charging stations that supply electricity for a fee or free.
The International Electrotechnical Commission modes definition (IEC 62196):
· Mode 1 – slow charging from a regular electrical socket (single- or three-phase)
· Mode 2 – slow charging from a regular socket but with some EV specific protection arrangement (e.g., the Park & Charge or the PARVE systems)
· Mode 3 – slow or fast charging using a specific EV multi-pin socket with control and protection functions (e.g., SAE J1772and IEC 62196)
· Mode 4 – fast charging using some special charger technology such as CHAdeMO
There are three connection cases:
· Case A is any charger connected to the mains (the mains supply cable is usually attached to the charger) usually associated with modes 1 or 2.
· Case B is an on-board vehicle charger with a mains supply cable which can be detached from both the supply and the vehicle – usually mode 3.
· Case C is a dedicated charging station with DC supply to the vehicle. The mains supply cable may be permanently attached to the charge-station such as in mode 4.
There are four plug types:
· Type 1 – single-phase vehicle coupler – reflecting the SAE J1772/2009 automotive plug specifications
· Type 2 – single- and three-phase vehicle coupler – reflecting the VDE-AR-E 2623-2-2 plug specifications
· Type 3 – single- and three-phase vehicle coupler equipped with safety shutters – reflecting the EV Plug Alliance proposal
· Type 4 – fast charge coupler – for special systems such as CHAdeMO
And so they say, charging station safety devices For user safety, all charging stations are equipped with a ground fault detector to reduce the risk of electrocution. Users are never exposed to dangerous voltages or currents, since connector pins are not energized until the connector is inserted properly in the EV charging socket and communication has been established between the vehicle and the charging station. In addition, the connector is sealed to protect the live components from the weather. Like all electrical equipment, charging stations are subject to safety standards, such as ANSI/UL 2202 “Electric Vehicle (EV) Charging System Equipment” and CSA-C22.2 No. 107.1 “General Use Power Supplies”. In addition, the cable, connector, ground fault detector and charging station as a whole must comply with all Technical Information Letters (TIL) published by the CSA, including: • TIL J-39 – EV cord sets • TIL A-35 – EV cord sets and power supply cords • TIL A-34 – EV connectors/couplers • TIL D-33 – Ground fault circuit interrupter (GFCI) • TIL I-44 – EV supply equipment certification These were still interim standards at the time of writing of this Guide. The CSA is working on a joint UL/CSA set of standards for Canada and the United States.
Use the following criteria when selecting a location: • Traffic, with the size of the installation to be based on the expected number of users • How much time EVs will spend at the station • Surrounding vehicle movement – vehicles stopped for charging must not hinder traffic flow • Winter use – the location must be cleared and accessible during winter and not be used as a snow dump or hinder snow clearing operations • Protection against collisions • Impact on pedestrian traffic – must not hinder pedestrian traffic or be subject to high pedestrian traffic and the associated increased risk of vandalism • Access to a cellular network, if required by the charging station • Feasibility of required excavation work • Proximity of distribution panel • Visibility of the charging station to encourage its use by drivers In addition, consider the mounting requirements (pole-mounted, anchored to a concrete base, etc.) and the length of the charging cable in relation to the typical location of E V charging sockets.
Class 1 Hazardous locations are defined in Rule 18-006 of the Code based on flammability and risk of flames spreading to an area containing a more persistent explosive gas atmosphere. Vents can be a constant source of explosive vapor and present a risk of propagation into underground tanks, which increases the hazard. Fuel pumps are a sporadic source of explosive vapor but the danger zone is larger due to the risk of spills. Near flammable gas sources In general, E V charging stations must be at least 3 m away from any flammable gas vent or exhaust. However, if the flammable gas is natural gas (methane), this clearance can be reduced to 1 m. In general, the charging cable/E V coupling point must be at least 3 m away from any flammable gas vent or exhaust. However, if the only flammable gas present is natural gas (methane), this clearance can be reduced to 1 m.* 4.7.3 Near water The installation of a charging station near water (swimming pool, hydro massage tub, spa, decorative pond, etc.) must comply with the Code.
Street side In addition to the general requirements for public charging stations the following must be taken into account for street side installation: • Availability of power supply at the required voltage • Installation and connection of equipment and, if required, of a distribution panel with the necessary voltage • Excavation work affecting the street or sidewalk • Protection against being hit by vehicles or machinery (installation of bollards or bumper posts) • Contractor expertise (e.g., if the charging station is anchored to a building or civil structure, the contractor must hold a subclass 11.2 licence, “Special equipment and products”8 ) • Municipal bylaws in effect
In general, the charging cable/E V coupling point must be at least 3 m away from any flammable gas vent or exhaust. However, if the only flammable gas present is natural gas (methane), this clearance can be reduced to 1 m.* 4.7.3 Near water The installation of a charging station near water (swimming pool, hydro massage tub, spa, decorative pond, etc.) must comply with Section 68 of the Code. 4.7.4 Streetside In addition to the general requirements for public charging stations (Section 4.4 of this Guide), the following must be taken into account for streetside installation: • Availability of power supply at the required voltage • Installation and connection of equipment and, if required, of a distribution panel with the necessary voltage • Excavation work affecting the street or sidewalk • Protection against being hit by vehicles or machinery (installation of bollards or bumper posts) • Contractor expertise (e.g., if the charging station is anchored to a building or civil structure, the contractor must hold a subclass 11.2 licence, “Special equipment and products”8 ) • Municipal bylaws in effect
The requirements for installing multiple stations are essentially the same as for a single installation, apart from the ones pertaining to the communication infrastructure between smart stations, if applicable. Each charging station must be supplied by a dedicated branch circuit, and the electrical installation must meet the following Code requirements: • One breaker for each station • One branch circuit for each station • A distribution panel with the appropriate capacity If the project includes plans for future expansion, it is strongly recommended that all civil engineering work for the second phase (concrete bases and underground conduits) be completed in advance, during the first phase. It is not, however, necessary to take future needs into account when dimensioning the electrical equipment.