View Full Version : National Electric Code Compliance
Mike Healy 08-19-2009, 07:37 AM I apologize if this subject has been brought up previously. Has G.M. identified where the consumer or electrical tradesman can acquire the required Electric Vehicle Supply Equipment? My 2005 copy of the National Electric Code requires among other things:
625.18 INTERLOCK: De-energizes the electric vehicle connector when the connector is uncoupled from the vehicle.
625.19 AUTOMATIC DE-ENERGIZATION OF CABLE: An automatic means to de-energize the cable conductors upon exposure to strain of pulling on the conductor.
625.22 PERSONNEL PROTECTION SYSTEM: Cord-and-plug-connected electric vehicles supply equipment requires an interrupting device of a listed personnel protection system shall be an integral part of the attaching plug or within 12 inches of the plug.
625.25 LOSS OF PRIMARY SOURCE: A means shall be provided that energy cannot be back fed through the vehicle and supply equipment to the premises wiring system.
Has anybody worked on getting this type of protective devices approved and readily available on the market????
Mike
misslexi 08-19-2009, 08:31 AM All good questions, perhaps that's why the Volt's wall charger appears to be more complex than a simple extension cord.
Perhaps Tesla has addressed some of these, maybe Prowler will check in.
Texas 08-19-2009, 09:58 AM 625.25 LOSS OF PRIMARY SOURCE: A means shall be provided that energy cannot be back fed through the vehicle and supply equipment to the premises wiring system.
Well, this will tick off all of those that want to use the Volt as a backup generator. Besides, this goes against the smart-grid concept where the Volt's battery will be connected to the grid. Think of it as a solar system with battery backup that has the fortune of having the sun shine on it when the homeowner needs it. In that case, the inverter only needs to disconnect from the dead grid line. The house remains powered.
Every time I look at a typical and common mercury thermostat I realize just how far we can go to improve the efficiency of our wasteful energy use. We Americans can waste energy like no other. We are kings!
The smart-grid and the electrification of transportation means things are going to change. There is currently billions of dollars about to be granted for smart-grid projects. The results of these will lead to new specifications, regulations, procedures, standards, etc.
misslexi 08-19-2009, 10:37 AM Well, this will tick off all of those that want to use the Volt as a backup generator. Besides, this goes against the smart-grid concept where the Volt's battery will be connected to the grid.
I'm not so sure I'd want my battery being arbitrarily discharged and charged by the smart grid, potentially shortening it's life without compensation. Has that been addressed by the smart grid proponents?
Of course, if my battery is leased with no usage caps, then I could care less.
Jim Rowland 08-19-2009, 12:12 PM I apologize if this subject has been brought up previously. Has G.M. identified where the consumer or electrical tradesman can acquire the required Electric Vehicle Supply Equipment? My 2005 copy of the National Electric Code requires among other things:
625.18 INTERLOCK: De-energizes the electric vehicle connector when the connector is uncoupled from the vehicle.
625.19 AUTOMATIC DE-ENERGIZATION OF CABLE: An automatic means to de-energize the cable conductors upon exposure to strain of pulling on the conductor.
625.22 PERSONNEL PROTECTION SYSTEM: Cord-and-plug-connected electric vehicles supply equipment requires an interrupting device of a listed personnel protection system shall be an integral part of the attaching plug or within 12 inches of the plug.
625.25 LOSS OF PRIMARY SOURCE: A means shall be provided that energy cannot be back fed through the vehicle and supply equipment to the premises wiring system.
Has anybody worked on getting this type of protective devices approved and readily available on the market????
Mike
Here are those same sections out of the 2007 California electrical Code which is currently enforced in Ca.
All is not doom and gloom. Alternate methods are also allowed on a case by case basis.
625.18 Interlock. Electric vehicle supply equipment shall
be provided with an interlock that de-energizes the electric
vehicle connector and its cable whenever the electric
connector is uncoupled from the electric vehicle. An
interlock shall not be required for portable cord-and-plugconnected
electric vehicle supply equipment intended for
connection to receptacle outlets rated at 125 volts, single
phase, 15 and 20 amperes.
625.19 Automatic De-Energization of Cable. The
electric vehicle supply equipment or the cable-connector
combination of the equipment shall be provided with an
automatic means to de-energize the cable conductors and
electric vehicle connector upon exposure to strain that
could result in either cable rupture or separation of the
cable from the electric connector and exposure of live
parts. Automatic means to de-energize the cable conductors
and electric vehicle connector shall not be required for
portable cord-and-plug-connected electric vehicle supply
equipment intended for connection to receptacle outlets
rated at 125 volts, single phase, 15 and 20 amperes.
IV. Control and Protection
625.21 Overcurrent Protection. Overcurrent protection
for feeders and branch circuits supplying electric vehicle
supply equipment shall be sized for continuous duty and
shall have a rating of not less than 125 percent of the
maximum load of the electric vehicle supply equipment.
Where noncontinuous loads are supplied from the same
feeder or branch circuit, the overcurrent device shall have a
rating of not less than the sum of the noncontinuous loads
plus 125 percent of the continuous loads.
625.22 Personnel Protection System. The electric vehicle
supply equipment shall have a listed system of protection
against electric shock of personnel. The personnel
protection system shall be composed of listed personnel
protection devices and constructional features. Where cordand-
plug-connected electric vehicle supply equipment is
used, the interrupting device of a listed personnel
protection system shall be provided and shall be an integral
part of the attachment plug or shall be located in the power
supply cable not more than 300 mm (12 in.) from the
attachment plug.
625.23 Disconnecting Means. For electric vehicle supply
equipment rated more than 60 amperes or more than 150
volts to ground, the disconnecting means shall be provided
and installed in a readily accessible location. The
disconnecting means shall be capable of being locked in
the open position.
625.25 Loss of Primary Source. Means shall be provided
such that, upon loss of voltage from the utility or other
electric system(s), energy cannot be back fed through the
electric vehicle and the supply equipment to the premises
wiring system unless permitted by 625.26.
625.26 Interactive Systems. Electric vehicle supply
equipment and other parts of a system, either on-board or
off-board the vehicle, that are identified for and intended to
be interconnected to a vehicle and also serve as an optional
standby system or an electric power production source or
provide for bi-directional power feed shall be listed as
suitable for that purpose. When used as an optional standby
system, the requirements of Article 702 shall apply, and
when used as an electric power production source, the
requirements of Article 705 shall apply.
Texas 08-19-2009, 12:31 PM I'm not so sure I'd want my battery being arbitrarily discharged and charged by the smart grid, potentially shortening it's life without compensation. Has that been addressed by the smart grid proponents?
Of course, if my battery is leased with no usage caps, then I could care less.
Yes, if you own the asset you will be compensated for it's use. In the case of BP, they own the asset and will make sure you are charged up and ready for your next trip. If you allow them to delay charging then they will reward your cooperation. I believe this is the new model for the smart-grid where everyone becomes both sinks and sources of energy. Energy becomes the new currency.
omnimoeish 08-19-2009, 01:26 PM Check this out. Ford is working on addressing some of these issues.
http://www.allcarselectric.com/blog/1034386_ford-unveils-vehicle-to-power-grid-communication-system
prowler 08-19-2009, 10:29 PM All good questions, perhaps that's why the Volt's wall charger appears to be more complex than a simple extension cord.
Perhaps Tesla has addressed some of these, maybe Prowler will check in.
My first reaction is that an average Volt purchaser isn't going to be conversant in the NEC and just wants to plug the car in. Yes, Tesla is about as close as possible to an "appliance" where you can almost do this.
Not really sure what the complete question is here, but this is something that I wrote and posted on another Board that may be of interest:
Originally posted by .....
3 cents a mile - not too bad!!!
you mentioned the "charger" on the wall, is it supplying DC to the car, so if you went on a trip you would need a charger and not just an AC outlet?
AHhhh, yes, my favorite picture - just drive past ALLLL the gas stations, pull into the garage and plug into the charger on the wall:
http://i300.photobucket.com/albums/nn15/sunpowr/2009_05_09_Tesla/chrgng-1.jpg
The Roadster actually has the charger (and intelligence) in the car and controls the draw from an AC circuit (from 120 Volt/12 Amp through 240 Volt/70 Amp - actual draw, which is limited to 80% of the circuit rating).
The "cords" and wall-mount unit get complicated for protection purposes (GFCI and such), but in the end, are just connection cords. The wall-mount is the "fast-charger" that will charge a full 244 mile "tank" in 3-1/2 hours.
Tracing the power connections in the wall mount (there's also monitoring connections), the end result is simply a 240 Volt feed into one side of a contactor going into the charging cord on the output side. Everything else in there is safety circuitry to determine whether to let the car draw up to the 70 Amp maximum its allowed.
The REALLY FAST chargers you may have heard about in development (45 minutes for the Tesla Model S, 10-minutes for ?????) are DC where they need to charge a HUGE DC repository (battery bank, supercapacitors, etc.) and then plug in the car battery for a DC-DC power dump (like a firehose filling a 5-gallon pail). Lots of heat, VERY large conductors, and some problems to be worked out. If I remember the quote, Burt Rutan once said that the theoretical limit to how quick you can charge an electric car is 3-1/2 seconds. This link may start you on the hunt if you're interested:
http://www.popularmechanics.com/blogs/science_news/4199534.html
-SPARKZZ
http://i300.photobucket.com/albums/nn15/sunpowr/2009_05_09_Tesla/th_signtur.jpg
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