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Installing a NEMA 14-50 plug to HPWC input

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I have a 4 wire NEMA 14-50 outlet installed when I first got my car and would use the charge cable got charge. I recently got a HPWC that I was hoping to mount on the wall and install a NEMA plug that goes to my existing outlet. Upon further I inspection I noticed the HPWC only uses the 3 wire configuration and recommends grounding the neutral. Has any one done this type of install? What did you do with your neutral lead? Ground it in the charger or convert to three wire before the HPWC?
 
I'm a little confused, and pardon if I don't understand. You're wanting to plug the HPWC into the NEMA 14-50 outlet? Wouldn't that defeat the advantage of the HPWC?
I wouldnt say it defeats the purpose. Its just an alternate way to install it without making permanent modifications to the existing infrastructure. It allows me to use my existing plug 14-50 plug for the charger and remove the charger if i ever need the plug. I consider it the simple option compare to installing conduit and modifying my existing outlet. It also ensures i never have two loads off the same breaker, cause the plug would be occupied by the charger (rather than taping off the outlet to the charger). I only need the 40amp charge so i wont be using the 80amp option.
 
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The HPWC only needs 3 wires, L1-L2 for 240 Volts, and ground. Just use a 3-wire cable and connect to L1, L2, and Ground in 14-50 Plug, but don't connect anything to the neutral pin in the 14-50 plug.

Be sure to set the DIP switches in the HPWC to 50 Amp breaker/40 Amp charging.
 
(Update: Cottonwood posted a good reply while I was typing this, but I will leave mine as-is with the additional information.)

Interesting question. The EVSEs that are sold with a plug have a 12" cable due to code requirements.

A NEMA 14-50 cable will work but Tesla doesn't make it easy with the hole that must be cut out of either the side or back of the HPWC. Be sure to set the dip switches to limit the amperage to 40 amps maximum. Since there are two versions of HPWC, follow the correct instructions for your HPWC.

https://www.teslamotors.com/sites/default/files/blog_attachments/ms_hpwc_installation_guide.pdf

https://my.teslamotors.com/sites/de...wall_connector_install_guide_northamerica.pdf

Looking at both installation guides, the "50A Breaker" and "40A Supplied" dip switch settings appear to be the same.

The green ground wire would be used for the mandatory ground connection. The white neutral wire is NOT used as shown in the 220/240 Single Phase illustration.

Ideally, it would be excellent to have a qualified electrician to do the work or double check what you are planning or have done. The electrical codes exist to protect us from harm and property from fire. Work safely and follow all the suggested installation instructions for maximum satisfaction.

If you are looking for a reasonably priced NEMA 14-50 cable, here is one that has 6 gauge wires for the 240 volt connection and 8 gauge for ground and neutral. The length is 4' and the attached connectors are for a range, so they would be removed for HPWC installation and to shorten the cable for code requirements. Again, getting advice from an electrician and reading Tesla's warnings (shown below) is highly recommended.

Range Cord, 4 8/2, Ring, SRDT, Black, UL Listed, NUCORD 94520

"WARNINGS: The Wall Connector must be grounded through a permanent wiring system or an equipment grounding conductor. Do not install or use the Wall Connector near flammable, explosive, harsh, or combustible materials, chemicals, or vapors.
Turn off input power at the circuit breaker before installing or cleaning the Wall Connector.
Use the Wall Connector only within the specified operating parameters.
The Wall Connector is designed only for charging a Tesla vehicle (excluding Tesla Roadster). Do not use it for any other purpose or with any other vehicle or object.
Stop using and do not use the Wall Connector if it is defective, appears cracked, frayed, broken, or otherwise damaged, or fails to operate.
Do not attempt to open, disassemble, repair, tamper with, or modify the Wall Connector. The Wall Connector is not user serviceable. Contact Tesla for any repairs.
Do not use the Wall Connector when you, the vehicle, or the Wall Connector is exposed to severe rain, snow, electrical storm, or other inclement weather.
When transporting the Wall Connector, handle with care. Do not subject it to strong force or impact or pull, twist, tangle, drag, or step on the Wall Connector, to prevent damage to it or any components.
Protect the Wall Connector from moisture, water, liquid, and foreign objects at all times. If any exist or appear to have entered, damaged, or corroded the Wall Connector, do not use the Wall Connector.
Do not touch the Wall Connector’s end terminals with sharp metallic objects, such as wire, tools, or needles. Do not forcefully fold any part of the Wall Connector or damage it with sharp objects.
Do not insert foreign objects into any part of the Wall Connector.
Do not use the Wall Connector when a vehicle cover is on the vehicle.
Use of the Wall Connector may affect or impair the operation of any medical or implantable electronic devices, such as an implantable cardiac pacemaker or an implantable cardioverter defibrillator. Check with the electronic device manufacturer concerning the effects that charging may have on such electronic devices before using the Wall Connector.


CAUTIONS:
Incorrect installation and testing of the Wall Connector could potentially damage either the vehicle’s Battery and/or the Wall Connector itself. Any resulting damage is excluded from the warranty for both the vehicle and the Wall Connector.
Do not operate the Wall Connector in temperatures outside its operating range of -22°F to 113°F (-30°C to +45°C).
Ensure that the charge station’s supply cable is positioned so it will not be stepped on, tripped over, or subjected to damage or stress.
Do not use cleaning solvents to clean any of the Wall Connector’s components. The outside of the Wall Connector, the charging cable, and the connector end of the charging cable should be periodically wiped with a clean dry cloth to remove accumulation of dirt and dust.
Be careful not to damage the circuit board when removing the power entry knock-out."
 
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See the FAQ, link in my signature or here: FAQ: Home Tesla charging infrastructure QA. It describes the issues associated with this in the section entitled "CAN I ATTACH A CORD AND PLUG TO MY HPWC AT THE 50A SETTING?"

It should be known that while the instructions shipped with the wall connector don't specifically demand "permanent wiring methods only", Tesla has stated in other forums that it is intended as such. Therefore, it's technically legal, but Tesla doesn't intend it as such.

As noted, by code the maximum cord length is 12".
 
Yeah i saw those notes from the FAQ. I was gonna proceed with the cord approach but you're all guilt tripping me into just hard-wiring it instead. Oh well, might as well just suck it up. It a look better in the end that way anyways. :D

FWIW,
I think hard-wiring the HPWC s a smart move.
This is a device that is often used unattended, at night for hours and everyday.
Hard-wiring connection are the most robust and reliable electrical connections and if something should go wrong the wiring connection are in a rated electrical enclosure.


As for HPWC and the required wiring method, I don't understand the interpretation/difference between the warning instruction that state: "Wall Connector must be grounded through a permanent wiring system or an equipment grounding conductor" and the desire to include wording such as "permanent wiring methods only" in the instructions.

In reference to the EVSE, UL Standard (UL2954) under which the HPWC is listed it is consistent with the installation manual for the wiring method and states "For a permanently connected product: Grounding Instructions - The products must be connected to a grounded, metal, permanent wiring system, or an equipment-grounding conductor..."

With regard to the Listing standard the HPWC's Installation Manual does not include any reference to a flexible cord service requirements, cord wire-gauge/output amperage or maximum cord length i.e., "1.8m (6 feet) for stationary EV cord sets that are wall or ceiling mounted" and/or grounding instructions for a corded EVSE installation.
Also, if the HPWC could be used with a flexible cord the installation manual would be requires to include all the warning for corded use included in the UMC Manual, i.e. 'do not use with extension cord. conversion plugs, do not disconnect while vehicle is charging, do not connect to a power outlet that is not properly grounded', etc.

Finally, if you discuss this directly with the group at Tesla responsible for the HPWC they will state definitively "Wall Connector is designed to be mounted on awall or post and hardwired to the electrical panel".


Yep, I know other disagree...however those are the facts;
 
As for HPWC and the required wiring method, I don't understand the interpretation/difference between the warning instruction that state: "Wall Connector must be grounded through a permanent wiring system or an equipment grounding conductor"

PLEASE stop misleading people - you keep bringing this up and your interpretation is an impossible one, or we would consider every appliance in our homes "ungrounded" per the code. An "equipment grounding conductor", as defined by the NEC, is a ground. It can be contained in a cord, carried in a conduit, or can exist as part of a properly installed conduit/raceway system. NEC 250.118 lists "Types of Equipment Grounding Conductors", very first item: "(1) A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape." That includes power supply cords. The green wire in a power cord IS an "equipment grounding conductor" and meets the requirements; therefore, the Wall Connector is indeed "grounded through [...] an equipment grounding conductor" per the requirements. Telling people otherwise is spreading misinformation.

Yep, I know other disagree...however those are the facts;

There are the facts, and there are your interpretations. I understand you have a strong allergy to an HPWC being connected via cord-and-plug, but do not use that to spread false information. State your opinion without making up false facts to suit it.

I have been forthright in stating that a program manager at Tesla has indeed spelled out the intentions as having the wall connector for permanent wiring installations and does not recommend connecting it via cord. However, Tesla does admit and concede that their current instructions do not prohibit the cord-and-plug connection as it relates to the code. When their written installation guide instructions dictate "permanent wiring methods only", then they will have limited it officially and it will be required to follow those instructions (NEC 110.3). I don't recommend connecting via cord-and-plug, but I will also tell people that it is indeed currently legal to do so, should that be their desire.

The UL standard you reference does indeed permit cord-and-plug connected equipment, and there are a significant number of brands who list cord-and-plug connected wall connectors under that very standard. As the device was tested and listed with a terminal block for inputs, the UL testing and listing will not apply to how the power is delivered to the device and makes no assumption about how that power is delivered.

You can state your opinion about whether the device should be cord-and-plug connected, but by the letter of the law, it is indeed legal and code-conforming to connect the device via cord-and-plug as long as it meets the requirements in NEC 625 (12" maximum length). To state anything to the contrary is spreading false information.
 
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PLEASE stop misleading people - you keep bringing this up and your interpretation is an impossible one, or we would consider every appliance in our homes "ungrounded" per the code. An "equipment grounding conductor", as defined by the NEC, is a ground. It can be contained in a cord, carried in a conduit, or can exist as part of a properly installed conduit/raceway system. NEC 250.118 lists "Types of Equipment Grounding Conductors", very first item: "(1) A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape." That includes power supply cords. The green wire in a power cord IS an "equipment grounding conductor" and meets the requirements; therefore, the Wall Connector is indeed "grounded through [...] an equipment grounding conductor" per the requirements. Telling people otherwise is spreading misinformation.



There are the facts, and there are your interpretations. I understand you have a strong allergy to an HPWC being connected via cord-and-plug, but do not use that to spread false information. State your opinion without making up false facts to suit it.

I have been forthright in stating that a program manager at Tesla has indeed spelled out the intentions as having the wall connector for permanent wiring installations and does not recommend connecting it via cord. However, Tesla does admit and concede that their current instructions do not prohibit the cord-and-plug connection as it relates to the code. When their written installation guide instructions dictate "permanent wiring methods only", then they will have limited it officially and it will be required to follow those instructions (NEC 110.3). I don't recommend connecting via cord-and-plug, but I will also tell people that it is indeed currently legal to do so, should that be their desire.

The UL standard you reference does indeed permit cord-and-plug connected equipment, and there are a significant number of brands who list cord-and-plug connected wall connectors under that very standard. As the device was tested and listed with a terminal block for inputs, the UL testing and listing will not apply to how the power is delivered to the device and makes no assumption about how that power is delivered.

You can state your opinion about whether the device should be cord-and-plug connected, but by the letter of the law, it is indeed legal and code-conforming to connect the device via cord-and-plug as long as it meets the requirements in NEC 625 (12" maximum length). To state anything to the contrary is spreading false information.

With all due respect, What was all that?
FlasherZ, you are the one that is misleading and misinterpreting the code requirements and have yet to understand the mandatory rules for equipment installation in the NEC and requirements from the NRTL Standard as stated in the Tesla “..HPWC Installation Manual” as those are the requirements the authorities (AHJ) and user (equipment owner) “SHALL” follow.

You keep going around asking for the opinion of others and adding it to your own and surmising in your own mind that you understand the only reasonable requirements.

However, there are NRTL documents and standards that are the Bible for equipment safety, testing, installation, use and required instruction included with the product.

I anticipate you have yet to read and understand the NRTL Standards as you insist you have all the knowledge required from the NEC.
When there is nothing further from the truth; as the NRTL and manufacture have control over the listing, labeling and conditions of installation and use not how you personally decide to interpret the cord connected equipment requirements in the NEC

FACT 1: NEC- Requirements for Electrical Installation, states,
“110.3 Examination, Identification, Installation, and Use of Equipment.
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.”

FACT 2: UL 2594 - Electrical Vehicle Supply Equipment, states,
“Instructions
76 General
76.1 A device shall be provided with legible installation, operation and as applicable user maintenance instructions …and instructions pertaining to risk of fire or electrical shock associated with the use or the device.”

“78 Installation Instructions
78.1 Installation instructions shall contain all the information needed to install the product for use as intended, and shall be proceeded by the heading “Installation Instructions” or the equivalent.”

FACT 3: Tesla Wall Connector Installation Manual
“Warnings:
The High Power Wall Connector must be grounded through a permanent wiring system or an equipment grounding conductor.”
And for extra measure..
“The High Power Wall Connector is designed only for charging a Tesla vehicle (excluding Tesla Roadster).
Do not use it for any other purpose or with any other vehicle or object.”


FACT 4: UL 2594 states,
”77.4 The instructions pertaining to a risk of fire or electrical shock, or the installation instructions shall include the following items in (a) and (b)…
(a)For a ground, cord connected product…
Grounding Instructions…Warning – Improper connection of the equipment-grounding conductor is able to result in a risk of electrical shock…

(b) For a permanently connected product….
Grounding Instructions - The product must be connected to a grounded, metal, permanent wiring system, or an equipment-grounding conductor.”

I anticipate from the facts listed above (while not complete) you and others can extrapolate that since the HPWC does not include instructions for being cord connected, the product was not tested, listed or labeled for cord connected installation.

Hence, if the product is not tested, listed or labeled and the instruction do not include the cord connected installation instructions you cannot as an authority (AHJ) infer on your own the requirements and therefore just because the NEC includes requirements for cord connected equipment you can then extrapolate that they apply to the HPWC and discard the Tesla HPWC Installation Manual and NRTL product installation manual requirements.

Reasonable in your mind? Probably not - but those are the facts…
End of Story…
 
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Oh no, please guys. This is giving me bad flashbacks of when I read electrical forums. Most threads seem to degenerate into two guys arguing over different rules sections in multiple code docs. This really isn't a very important point, can we just leave it here?
 
Hey Cosmacelf, It's actually an important point because it is a question that is asked of me pretty frequently in PM's (at least once every 2 months), or I would simply let it go as a corner case. I won't argue it head-on with mi6bigdog (because I agree it's counter-productive), but I feel the correct information should be posted so that others aren't mislead as to what inspectors look for. I do know what inspectors look at, and look for, because I've been on the receiving end of their opinions and the green and red tags that govern whether the power can be turned on or not. :)

Because of the controversy, when mi6bigdog first brought up his concerns, I sought the professional opinions from several (5+) chief municipal and county electrical inspectors - those whose opinions are the only ones that matter - and all of them agreed that nothing in Tesla's instructions currently preclude it, regardless of Tesla's intentions. None of them said they would fail an inspection with a cord-and-plug connected HPWC given the current instructions as published by Tesla as long as it followed the requirements for cord length in article 625. That's why the FAQ is written the way it is -- spell it out that Tesla states the HPWC was designed for permanent installation, but that Tesla had also agreed and conceded the point that their instructions do not include a hard requirement that it be installed with permanent wiring methods and that it's legal to do so. Anyone who finds a chief electrical inspector for a municipality, county, or even a state whose opinion differs can point him at me and, after confirming, I'll be happy to publish his/her professional opinion in the FAQ as a counter-point to the existing material.

Sorry that the longer-tenured members have to see it again, but all the material about the NRTL and UL standards and such has no bearing on how those who are charged with implementing the electrical standards in their jurisdictions look at it - they look at Tesla's explicit instructions for what MUST [NOT]. SHOULD [NOT], and MAY [NOT] do, and will fall back on the letter of the NEC where there is no explicit instruction. When they change the instructions with explicit information (perhaps they'll upgrade the HPWC to re-add 60/90A breaker settings for Model X), then I'll update the FAQ and acknowledge the new requirement.

My best to y'all, you won't see any more responses to the same argument in this thread (but to everyone else, by all means ask questions in regard to the topic here or in the FAQ thread).

(PS - I agree with you on electricians' forums, I see the same thing and it's very sad because people just want the correct, safe answers that will help them through the processes of permitting, installation, and inspection. I find usually the problem is caused by some people who don't regularly work with electric infrastructure and have worked only with tangentially related material; e.g., someone who worked with approving fire door ratings in a testing lab but wants to offer authoritative advice about how fire brigades should run their truck pumps. In one forum I read on a regular basis, there is a former armed services electrician - with no disrespect to his service to the country - who hasn't done any electrical work in residential building trades and isn't licensed, yet continues to give out horrible advice that can lead to people being hurt or killed. In the most egregious and obvious cases, mods step in and knock out the patently false information (suspending him for a short period of time), but other times it devolves into the type of battle that you describe, generally derailing the OP's desire to get helpful information on how he/she can do an installation that's safe and will pass inspection. That's why on the topics that are contentious here, I consult with a number of people who would judge it authoritatively (and frankly my opinion doesn't really matter). If it's truly an opinion with multiple options - like the choice of EMT vs. IMC vs. rigid conduits vs. NM cable, etc. - then you'll get my opinion but you'll know where personal choice takes effect.)
 
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Hey Cosmacelf, It's actually an important point ... Because of the controversy, when mi6bigdog first brought up his concerns, I sought the professional opinions from several (5+) chief municipal and county electrical inspectors - those whose opinions are the only ones that matter - and all of them agreed that nothing in Tesla's instructions currently preclude it, regardless of Tesla's intentions. None of them said they would fail an inspection with a cord-and-plug connected HPWC given the current instructions as published by Tesla as long as it followed the requirements for cord length in article 625. That's why the FAQ is written the way it is -- spell it out that Tesla states the HPWC was designed for permanent installation, but that Tesla had also agreed and conceded the point that their instructions do not include a hard requirement that it be installed with permanent wiring methods and that it's legal to do so. Anyone who finds a chief electrical inspector for a municipality, county, or even a state whose opinion differs can point him at me and, after confirming, I'll be happy to publish his/her professional opinion in the FAQ as a counter-point to the existing material.

Sorry that the longer-tenured members have to see it again, but all the material about the NRTL and UL standards and such has no bearing on how those who are charged with implementing the electrical standards in their jurisdictions look at it - they look at Tesla's explicit instructions for what MUST [NOT]. SHOULD [NOT], and MAY [NOT] do, and will fall back on the letter of the NEC where there is no explicit instruction. When they change the instructions with explicit information (perhaps they'll upgrade the HPWC to re-add 60/90A breaker settings for Model X), then I'll update the FAQ and acknowledge the new requirement.

My best to y'all, you won't see any more responses to the same argument in this thread (but to everyone else, by all means ask questions in regard to the topic here or in the FAQ thread).

(PS - I agree with you on electricians' forums, I see the same thing ...

FlasherZ,
Interesting position for you to take, as I know some longer tenured professionals it is better to ignore because following their lead would only perpetuate bad habits.

I am unsure how to respond to someone that rejects the very NRTL standards for all wiring, devices, material and equipment approval and iterated over and over throughout the NEC. I anticipate you believe the NEC stands on its own as an authoritative document; when nothing is further from the truth!!

Cops have authority and nothing can stop them form ignoring the procedures and laws at the initial encounter; so to is an occurrence with an AHJ. However, one can appeal their decisions with facts and relevant NRTL documents.

I would submit, if individuals responsible for a jurisdiction revert to the NEC only when the installations instruction are silent, not well understood, then they are over thinking the problem and over-stepping their jurisdictional authority. As there is no “exception” in the NEC that allows an installation method to be permitted if the installation instruction does not explicitly excluded it in the listing instructions. Hence, if you install equipment using a method not included in the product instructions the installation may very well violate the listing and NRTL testing that allowed the equipment to be installed by the NEC in the first place. As explained in the “GuideInfo” below.

It is absurd that you believe ”all the material about the NRTL and UL standards and such has no bearing on how those who are charged with implementing the electrical standards in their jurisdictions”. Given this statement, you have developed some bad habbits.

Again a fact you seem to not recognize as the terms “Listing” or “Listed” or “Labeled” are all in reference to the NRTL’s standards, evaluation, testing, installation instructions and intended use as listing/labeling are mandatory requirements for all wiring, devices, material and equipment approval and iterated throughout the NEC and the “record is made generally available through promulgation” by the NRTL.

Specifically the sections below set up the mandatory requirements relative to the NRTL standards:
ARTICLE 90 - INTRODUCTION
90.7 Examination of Equipment for Safety. For specific items of equipment and materials referred to in this Code, examinations for safety made under standard conditions provide a basis for approval where the record is made generally available through promulgation by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service value determination through field inspections.

ARTICLE 110 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS
110.3 Examination, Identification, Installation, and Use of Equipment.
(A) Examination. In judging equipment, considerations such as the following shall be evaluated:
(1) Suitability for installation and use in conformity with the provisions of this Code
Informational Note: Suitability of equipment use may be identified by a description marked on or provided with a product to identify the suitability of the product for a specific purpose, environment, or application. Special conditions of use or other limitations and other pertinent information may be marked on the equipment, included in the product instructions, or included in the appropriate listing and labeling information. Suitability of equipment may be evidenced by listing or labeling.
(2) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided
(3) Wire-bending and connection space
(4) Electrical insulation
(5) Heating effects under normal conditions of use and also under abnormal conditions likely to arise in service
(6) Arcing effects
(7) Classification by type, size, voltage, current capacity, and specific use
(8) Other factors that contribute to the practical safeguarding of persons using or likely to come in contact with the equipment
(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Hence, there are no more important requirements document for implementing electrical standards and approving the intended use than the listing and labeling information. Therefore, how would you determine when equipment is correctly installed and used as intended, unless you reference the product instructions or if they seem inadequate in your judgement than the NRTL instructions included in the listing or labeling located in the UL Online Certification Directory for Product Category Guide.info.

While you seem to recognize that the HPWC (Instruction Manual) installation instructions are relevant for installation requirements you reject the instructions as being adequate when they are silent with respect to cord connected supply conductor installation methods. Yet you will also reject the explicit instructions when the intended use instructions states for “only for charging a Tesla Vehicle (excluding Tesla Roadster)” as I assume does not meet your expectations or assumption of what is safe as an intended use for a HPWC with an unlisted Tesla/J1772 adapter.


Competent AHJ’s will respect the NRTL information included in the NRTL listing as it is there for Free; below quoted from the:
UL Online Certification Directory
http://database.ul.com/cgi-bin/XYV/...n=versionless&parent_id=1073983908&sequence=1

“AALZ.GuideInfo - Electrical Equipment for Use in Ordinary Locations

  • “INSTRUCTIONS AND PRODUCT MARKINGS
These products are intended to be installed in accordance with the installation instructions provided with the product. It is critical that the cautionary statements and installation and operating instructions on the product and in accompanying literature be followed.”

  • “FIELD MODIFICATIONS
The UL Mark applies to the product as it is originally manufactured when shipped from the factory. Authorized use of the UL Mark is the manufacturer's declaration that the product was originally manufactured in accordance with the applicable requirements. UL does not know what the effect of a modification may have on the safety of the product or the continued validity of the UL certification mark unless the field modifications have been specifically investigated by UL. Unless UL investigates a modified product, UL cannot indicate that the product continues to meet UL's safety requirements.”

http://database.ul.com/cgi-bin/XYV/...n=versionless&parent_id=1073986568&sequence=1

FFWA.GuideInfo - Electric Vehicle Supply Equipment

  • USE
This category covers electric vehicle supply equipment with an input voltage rated 600 V ac or less, intended for indoor or outdoor use where power is required for the recharging of electric vehicle storage batteries. These products are intended to provide power to an on-board charger. These products include electric vehicle charging stations, electric vehicle power outlets and electric vehicle cord sets for use with electric vehicles in accordance with Article 625 of ANSI/NFPA 70, "National Electrical Code" (NEC). This category also covers accessories for use with electric vehicle charging stations and electric vehicle cord sets.” (i.e., Tesla/J1772 adapter)

What more can I say. Other than, if you truly understood the profession you would understand the importance of the NRTL standards and the listing instructions for the AHJ’s responsibilities.
 
Hey bigdog, dry up will ya. Nobody cares.

Actually this is a good topic I think, but the debate has definitely become heated. Since a plug-in HPWC could be useful to some people, perhaps this is something Tesla can address with guidelines that explicitly support a plug configuration or even an updated model that has a cord and plug, while at the same time offering the current model for those who prefer a hardwired configuration.
 
The subject is extremely interesting because of amendments to the National Electric Code. For example, while the NEC requires a 12" power supply cord factory installed by manufacturers, one amendment has the text: "power supply cord length for electric vehicle supply equipment fastened in place is limited to 6 ft". The EVSE industry requests changes to the NEC as the process of charging an electric vehicle matures. Here is a link to the "Tentative Interim Amendment" from 2011 quoted above that appears in the 2014 NEC draft.

http://www.nfpa.org/Assets/files/AboutTheCodes/70/TIA70-11-2.pdf

My suggestion is find products that meet your need without modification. A good example is when comparing ChargePoint and ClipperCreek and their 32 amp EVSE. ChargePoint requires a 40 amp circuit breaker when using their NEMA 6-50 plug while ClipperCreek allows a 50 amp circuit breaker with their NEMA 14-50 plug. This is a case where ClipperCreek engineered their EVSE to allow the higher supply amperage. The result is that the ClipperCreek customer won't have to install a 40 amp circuit breaker if they are using an existing 50 amp circuit breaker. (ClipperCreek also offers a higher amperage plug-in EVSE.)

ChargePoint Home - Hardware Installation

http://www.clippercreek.com/store/product/hcs-40p-32a-240v-charging-25-cord-nema-14-50-plug/

http://www.clippercreek.com/store/p...ng-station-25-ft-over-molded-cable-nema-6-50/

One more to mention. The following manufacturer installs a 6 foot power supply cable. Some customers on Amazon have commented that they couldn't get their installation approved in their city (It is not UL approved yet, but designed to meet UL certifications).

http://www.emotorwerks.com/products/online-store/171-juicebox-40-40-amp-evse-with-24-foot-cable

UPDATE: UL LLC submitted an amendment during 2015 that requests a removal of the 6 foot power supply cord length language and limits portable devices to 20 amps. Could this request lower the amperage of a future portable Tesla EVSE?

http://www.nfpa.org/Assets/files/AboutTheCodes/70/ProposedTIA 1168_NFPA 70.pdf
 
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Indeed there are many considerations and it depends upon the particular inspector. You'll find a few threads even here on TMC where the OP mentions an installation passed inspection for him/her, where another poster mentions the same installation being rejected. For example, there's a thread in the Model S section where a second meter was being installed to support the EV TOU rates, where pictures of unprotected service-entrance cable were seen coming out of the meter base and into the home -- municipal inspectors near me would reject that in a heartbeat, but his accepted it just fine, and his parents' home was provisioned the same way (the NEC requires service-entrance conductors be protected from damage).

In addition, some inspectors limit what they look at, while others want to know the "whole story". For example, you can properly install a NEMA 14-50 on a 50A breaker, and at the same time tell the inspector you're going to create an adaptor cord with a NEMA 5-15 receptacle to a 14-50 plug so that you can plug a refrigerator into it. Some inspectors will look at the installation, shrug, and pass it, because anything beyond the receptacle isn't a concern to him. Some will warn you "that sounds stupid" but will pass it. Others will red-tag you and demand you install a proper 5-15 outlet there instead of a 14-50 based on what you told them. What this means: if you attach a cord-and-plug to an HPWC, some inspectors might not even look at it at all, since a properly installed receptacle is what he's looking for.

The bottom line is that your appropriate inspector (municipal, county, or other building authority) has the final say, and that's the only person whose opinion matters. What I say is guidance but doesn't matter, which is why I consult with some of the local inspectors when there are controversies here. If you would like a definitive answer for your specific case, the building authority is the person you need to call - although I can provide guidance based on what I've seen. There are cases where I've felt strongly that I'm right, yet I capitulated and did what the inspector wanted because it wasn't worth going down the path of escalating it and encouraging the homeowner to file suit against the authority when escalation fails.

I can say definitively, however, that I've never had a municipal or county inspector ask to see a collection of Intertek and UL tags.
 
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The subject is extremely interesting because of amendments to the National Electric Code. For example, while the NEC requires a 12" power supply cord factory installed by manufacturers, IF another EVSE is designed for a power supply cord to be installed by the electrician, "power supply cord length for electric vehicle supply equipment fastened in place is limited to 6 ft". The EVSE industry requests changes to the NEC as the process of charging an electric vehicle matures. Here is a link to the "Tentative Interim Amendment" from 2011 quoted above that appears in the 2014 NEC draft.

From a building and installation standpoint, what is important is what's in the NEC. 625.17(A)(3)(a) states that if the GFCI protection for the EVSE is located in the unit itself, the maximum cord length is 12 inches. 625.17(A)(3)(b) grants up to 6 feet only "when the interrupting device of the personnel protection system is located at the attachment plug or within the first 300 mm (12 in.) of the cord". There is no exemption for EVSE's "designed for a power supply cord to be installed by the electrician" - if you have a reference I'd like to look at it.

(That said, as I've noted before - and even in my last post - some inspectors don't care beyond a receptacle or the end of the conduit when the appliance has a terminal block; the UMC to them is an appliance and electrical inspectors typically don't concern themselves with cord-and-plug attached appliances.)

UPDATE: UL LLC submitted an amendment during 2015 that requests a removal of the 6 foot power supply cord length language and limits portable devices to 20 amps. Could this request lower the amperage of a future portable Tesla EVSE?

You'll find a lot of TIA's submitted on a regular basis by interest groups. It's very rare that a TIA is adopted under emergency situations, but even when it is, most of the laws that codify the use of the NEC wouldn't pick them up anyway as they enact the NEC at a certain point. The last time I looked at the votes behind amendments, though, it was clear that there were several CMP members (the Code Making Panels) that were disagreeing on the very basics of EVSE (do UMC's really need to be considered EVSE and if so are they subject to electrical infrastructure code?)

One such example is below... it's clear that the CMP is hunting for relevance in this particular case. As I was reading the TIA and the voting comments, it was clear that some CMP members understand UMC-like EVSE and some don't. You can also see all the special interests that are involved in the policy making (e.g., manufacturers, installer unions, etc.):

lack of charging adaptors? - Page 2
 
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