FAQ: Home Tesla charging infrastructure Q&A

[miimura]

Sorry, didn't mean to confuse, what I typed was correct. Your USE-2/RHW-2 cable assembly may not be used similar to an NM-B (Romex) assembly. With a 6/2 or 6/3 NM-B cable, you may staple it directly to a stud, without running it in a raceway, when behind wallboard. NM-B may be run exposed in "inaccessible" areas, generally above 7'.

In contrast, when used as an RHW-2 rated conductor, your USE-2/RHW-2 assembly must be run in a raceway/conduit only. It may not be run in walls or along basement ceiling joists, etc, unless it is in a conduit. You must treat it as if it were an individual wire for protection means.

When run inside a wall or other inaccessible space, are the various types of plastic conduit allowed, or is it always metal conduit only?

 

[FlasherZ]

When run inside a wall or other inaccessible space, are the various types of plastic conduit allowed, or is it always metal conduit only?

Local code amendments may apply, but the NEC has a number of non-metallic conduit types that may be used inside a wall - rigid PVC (a/k/a "RNC" or rigid nonmetallic conduit), electric non-metallic tubing (a/k/a ENT or corrugated "smurf tube" because it's blue). There is also the ability to use LFNC (liquidtight flexible non-metallic conduit a/k/a FNMC), but that's pretty pricy for in-wall use (typically used for external connections of things like pool pumps and such), or more extreme conditions (> 130 deg F for example).

 

[AudubonB]

I do, indeed, finally, fully understand. Thank you again very much.

 

[FlasherZ]

It was a great run of 6 months without editing.

I added the following question to the FAQ:

AFTER VERSION 5.8.4, MY CAR "BACKS OFF" FROM THE CONFIGURED CHARGING CURRENT BY 25%. IT WORKED FINE BEFORE, SHOULD I BE CONCERNED?

It describes the backing off behavior, and how to start troubleshooting to help out.

I also put a "table of contents" at the top as a summary so that you can see what's in the FAQ (it's getting quite long and intra-post links aren't supported).

What other questions pop up that aren't addressed that I should answer?

 

[Robert.Boston]

Thanks, @FlasherZ. You might mention in this answer that, after addressing the wiring issue that caused the de-rating, the user should check that the charging rate is set correctly in the car. I noticed that mine set itself down to 30A and stayed there (i.e. never retested whether it was now safe to go back up to 40A).

 

[FlasherZ]

Thanks, @FlasherZ. You might mention in this answer that, after addressing the wiring issue that caused the de-rating, the user should check that the charging rate is set correctly in the car. I noticed that mine set itself down to 30A and stayed there (i.e. never retested whether it was now safe to go back up to 40A).

I added a paragraph... this good?

One other note: it has been noted that if you make an in-car change to the charging current while it has backed off, that it will retain that current as the default charging setting for that location. For example, if your car has backed down from 40 amps to a maximum of 30 amps, and you hit the arrows on the charging screen in an attempt to ramp it back up, it will keep 30 amps as your new normal charge current. Once you've checked and/or corrected your infrastructure, you should ensure that you reset your charging value to the maximum again in the car.

 

[Robert.Boston]

I had this shift to 30A occur even when I didn't manually make any change. I'd write this paragraph more simply:

One other note: After you have checked and/or corrected your infrastructure, you should check that the charging amperage of your car is set correctly. In some instances, the car may lower the maximum charging current below the maximum rate if instability in the current was detected.

 

[Canuck]

Most homeowners' and auto insurance policies in the United States have clauses that preclude payment of a claim in the case of unlawful behavior in various ways. My own homeowner's insurance has a clause that requires me to make any improvements to my property only in accordance with appropriate construction standards and take appropriate action when a deficiency is discovered to protect my property. Technically, my use of an extension cord could violate that.


To obtain an independent opinion, I contacted the claims department of a "top 5" homeowners' insurance company (as measured by premiums revenue) with whom I have no business relationship, and asked to speak to a supervisor who would take part in claims decisions. I asked the following question verbatim:


The answer I received had several parts:

* She said that for legal and regulatory reasons, policy prohibited her from answering a hypothetical situation with a definitive answer, so she could not state whether a claim would be paid or not.

* She said she strongly suggests that all improvements to property be done in compliance with all standards, codes, and laws to avoid the possibility of a claim denial.

* She said that technically, the policies that would be sold in nearly every state would indeed give them the legal right to deny a claim, one which could be challenged through arbitration and/or a court of law. Following settlement, arbitration, or a judgment that results in a reversal, the homeowner would then collect for the loss.

* A decision whether to pay or deny a claim would be dependent upon several factors, to include willfulness, degree of negligence, safety risk, cause of the loss, and other factors like cooperation.
This means that the homeowner will assume all risks of using a solution that does not comply with electrical codes; and that should the insurance company decide to deny a claim, recovery would be suspended until completion of legal challenge via arbitration or lawsuit.

Great post overall except I would like to add one thing. Don't always believe what "a supervisor who takes part in claims decisions" tells you. They are often wrong. To say that the "degree of negligence" plays a role in determining coverage is laughable. Insurance companies are great at denying claims for a variety of reasons, but unless you intentionally burn your house down, you should seek independent legal advice (from a lawyer who restricts his practice to insurance claims) if you are denied coverage because you wired your own home contrary to the electrical code, or for any other reason not related to intentionally burning your house down. There is difference at law between an illegal act (the common exclusion in insurance policies) and a quasi-illegal act. For instance, if you are speeding and cause an accident do you have coverage? What if you run a red light? You've breached the Motor Vehicle Act -- so that's illegal like wiring your own house without a permit, right? No, wrong, of course you still have coverage. But what about being drunk? No coverage, why? because the criminal code deals with illegal acts - not the building code, electrical code, etc. Never take as fact what a claims supervisor tells you about your claim! Most have never studied insurance law, none have ever been to trial on these issues, and most are given advances based on how much they save the company in claim costs. For this reason, the Court are more and more awarding significant punitive damages (sometimes in the millions) for wrongfully denied claims. It's an unfair advantage when insurers have all the money and control and there's a clear inequality of bargaining positions. Insurance coverage is too be interpreted broadly, exclusions narrowly, any ambiguity is decided against an insurer, and I could go on and on. Countless fires are started by careless people who have done their own negligent wiring against the electrical code and most of those claims are paid by insurers. I'm not saying to do your own wiring - the article is correct in that you need to avoid fire risks and have it done by professionals. I'm just saying to seek legal advice if you are denied coverage for any fire in your home that you did not intentionally start yourself (i.e. arson) and don't always believe what claims supervisors tell you.

 

[FlasherZ]

In the US, building codes are codified in law, and very frequently come with criminal codes attached for violations of them (most of them being misdemeanor violations). I have a few examples scattered across this board that I've written over the past couple of years.

I have seen personally the case where an insurer failed to pay on a claim (for a nearby homeowner). The appeals process was fruitless, it was clear that building codes, and therefore the law, were violated and there was a specific clause in the policy for it.

My insurance policy has a specific clause that states they do not cover loss in case of violation of building codes:

2. We do not insure under any coverage for any loss which
would not have occurred in the absence of one or more
of the following excluded events. We do not insure for
such loss regardless of: (a) the cause of the excluded
event; or (b) other causes of the loss; or (c) whether other
causes acted concurrently or in any sequence with the
excluded event to produce the loss; or (d) whether the
event occurs suddenly or gradually, involves isolated or
widespread damage, arises from natural or external
forces, or occurs as a result of any combination of these:

a. Ordinance or Law, meaning enforcement of any
ordinance or law regulating the construction, repair
or demolition of a building or other structure.

Now, you're right, many states have different laws and take different positions on how much policyholders need to be protected from insurance companies. In all cases, as you rightly note, the insurance company holds the money and has much of the power. If they refuse to pay, it will be up to you to fight them, whether through administrative hearings, court, etc. All the while, you'll be out of at least some of the money, and perhaps out of a home.

And you're also right when you say that many times, those who have done their wiring illegally do get claims paid -- many times, damage makes it too difficult to determine that wiring was done improperly.

So, do you want to take that risk? It's up to you. I follow the codes for any improvement done to my home, even though a) there is no permit requirement and b) there is no inspection requirement; I do it out of safety concern for my family.

Unfortunately, there will always be people who believe that because it works, it must be safe. That's not always the case.

(Finally, you're right -- if you're denied on a loss claim due to this, you will want to talk to a legal specialist. In some cases, you may be able to recover even if you're in the wrong. I don't take any other position than to follow the codes as codified in law.)

 

[Canuck]

My insurance policy has a specific clause that states they do not cover loss in case of violation of building codes:



2. We do not insure under any coverage for any loss which
would not have occurred in the absence of one or more
of the following excluded events. We do not insure for
such loss regardless of: (a) the cause of the excluded
event; or (b) other causes of the loss; or (c) whether other
causes acted concurrently or in any sequence with the
excluded event to produce the loss; or (d) whether the
event occurs suddenly or gradually, involves isolated or
widespread damage, arises from natural or external
forces, or occurs as a result of any combination of these:

a. Ordinance or Law, meaning enforcement of any
ordinance or law regulating the construction, repair
or demolition of a building or other structure.

That's called an anticoncurrent causation clause. I'm guessing you have a State Farm policy. Here's some information on those particular types of insurance clauses:

"Some states, including California and Washington, have adopted a statutory or common law rule that insurance policies must provide coverage if the efficient proximate cause of loss is a covered peril. Courts in those jurisdictions have held that anticoncurrent causation clauses violate that rule, and therefore are unenforceable. Second, under the law of many states, an insurance policy must be interpreted in a manner that is consistent with the reasonable expectations of the policyholder. This doctrine is intended to compensate for the fact that most insurance policies are contracts of adhesion, drafted by the insurer and sold on a take it or leave it basis. Some courts, such as those in Mississippi, have concluded that anticoncurrent causation clauses are unenforceable because they defeat the policyholder's reasonable expectations of coverage when a covered peril is the proximate cause of loss. However, other courts, including those in Alaska, have found the clauses to be enforceable under the reasonable expectations doctrine. Those courts have concluded that the clauses are clear and unambiguous, and therefore policyholders could not reasonably expect coverage for risks excluded by them. Third, other courts which enforce these clauses do so under the laws of states which lack a proximate causation rule and which reject the reasonable expectations doctrine in favor of a rule that insurance policies are to be interpreted under the same rules as all other contracts. To these courts, anticoncurrent causation clauses are enforceable because they are clear and unambiguous, and entered into by parties who are free to contract as they wish. Not all property policies contain anticoncurrent causation clauses. Avoiding those provisions should be a high priority when selecting coverage."

When your policy comes up for renewal, you may wish to shop around for a policy that does not contain anticoncurrent causation clauses since it can erase your coverage in many areas of which you may not be aware.

So, do you want to take that risk? It's up to you. I follow the codes for any improvement done to my home, even though a) there is no permit requirement and b) there is no inspection requirement; I do it out of safety concern for my family.

Agreed - 100% I did say: "I'm not saying to do your own wiring - the article is correct in that you need to avoid fire risks and have it done by professionals. I'm just saying to seek legal advice if you are denied coverage for any fire in your home that you did not intentionally start yourself (i.e. arson) and don't always believe what claims supervisors tell you."

 

[FlasherZ]

I concede there are jurisdictions where these clauses may be unenforceable. In other cases, if the cause of the loss is the faulty wiring, it may not be a matter whether anticoncurrent causation language is legal or not. I try to paint the picture for the most general case, based on what the policies typically say.

I'm in Illinois, home to a very large insurer. Almost every policy here gets to include those clauses, unfortunately.

I will modify the language to state that you may have recourse in certain jurisdictions.

 

[Canuck]

Your article was excellent and I see no need to change it. I learned a lot from it. I hope you didn't take offence to my comments on one small part of it.

 

[FlasherZ]

No offense taken at all. You're right in that anyone who ends up suffering a loss and having a claim denied needs to do everything appropriate to try and recover... thanks for the feedback!

 

[russelthor]

FlasherZ:

I'm getting quotes for installation of the High Power Wall Connector (HPWC). One electrician (recommended by Tesla) says I must have a separate disconnect box, per NEC 625.23 "Disconnecting Means," in addition to the new 100-amp breakers in my existing circuit breaker panel (all agree that the existing CB panel is of sufficient size physically and electrically). I pressed him as to why a lock on the 100-amp breakers would not qualify and he shrugged and said, "I've never seen a lock on a residential CB that would meet the NEC requirements." (Que the sound of a cash register ringing: additional equipment; additional time; additional permit fee.)

So I called the City of Houston Building Permit office and spoke with an electrical inspector who said, in effect, "*I* would approve a lock on the CB, especially since you say your CB panel is right next to the future HPWC, meaning it is virtually impossible for another person to turn the service back on while it's being worked on."

Do you have any reference or best-practices material that confirms this simple interpretation? And where can I get such a lock - Home Depot?

 

[FlasherZ]

NEC 625.23 says that "portable means for adding a lock to the switch or circuit breaker shall not be permitted" which would seem to rule out a circuit breaker lock-out device typically used to lock-out/tag-out. That said, the AHJ is the final authority, and if your inspector said that he would accept it, then perhaps he and your electrician need to have a pow-wow.

As to where to get a lock, Amazon has a number of them and you can find them at Home Depot / Lowe's / etc. in various makes and models.

This is one of those code elements that I think is rather unneeded. Circuit breakers make sufficient disconnects and LO/TO procedures using portable breaker locks are perfectly reasonable - after all, OSHA accepts them. A locking tang on the circuit breaker panel door would be sufficient (this is what qualifies at my home), but an individually-added breaker lock-out wouldn't. So go with your inspector on this one.

 

[PhilBa]

My HPWC has a subpanel about 3 feet from it. The breaker was acceptable as a shut off device to both the electrician and the inspector (which is a state thing in WA). No lock was required.

FlasherZ:

I'm getting quotes for installation of the High Power Wall Connector (HPWC). One electrician (recommended by Tesla) says I must have a separate disconnect box, per NEC 625.23 "Disconnecting Means," in addition to the new 100-amp breakers in my existing circuit breaker panel (all agree that the existing CB panel is of sufficient size physically and electrically). I pressed him as to why a lock on the 100-amp breakers would not qualify and he shrugged and said, "I've never seen a lock on a residential CB that would meet the NEC requirements." (Que the sound of a cash register ringing: additional equipment; additional time; additional permit fee.)

So I called the City of Houston Building Permit office and spoke with an electrical inspector who said, in effect, "*I* would approve a lock on the CB, especially since you say your CB panel is right next to the future HPWC, meaning it is virtually impossible for another person to turn the service back on while it's being worked on."

Do you have any reference or best-practices material that confirms this simple interpretation? And where can I get such a lock - Home Depot?

 

[FlasherZ]

My HPWC has a subpanel about 3 feet from it. The breaker was acceptable as a shut off device to both the electrician and the inspector (which is a state thing in WA). No lock was required.

I've heard the same from a lot of people - that the inspectors aren't enforcing lock-out requirements of 625.23. Some tell me that they are not enforcing them if the disconnect/breaker is within sight of the HPWC, because you'd be able to watch the disconnect. Others just don't require the lock out at all.

 

[ElSupreme]

I recommend avoiding a 100A subpanel... A 125A subpanel will permit both the HPWC to charge at full load (80A) as well as the 14-50's full load (40A).

Can you not put a 100A and 50A breaker into a 100A sub-panel? With the obvious expectation that you wouldn't be both at the same time.

I am planning on installing a 100A sub panel in my garage. Powering a 60A and 40A circuit for two Clipper Creek HCS EVSEs. I was thinking of moving my existing 50A breaker (sub-panel has to be fed from this slot) for a NEMA14-50 outlet as a backup for the UMC if I ever needed it. And filling out the sub-panel I was planning on buying.

Knowing full well that I couldn't charge 3 cars all at once. And that you couldn't fit more than 2 cars in my garage anyway.

 

[FlasherZ]

Can you not put a 100A and 50A breaker into a 100A sub-panel? With the obvious expectation that you wouldn't be both at the same time.

I am planning on installing a 100A sub panel in my garage. Powering a 60A and 40A circuit for two Clipper Creek HCS EVSEs. I was thinking of moving my existing 50A breaker (sub-panel has to be fed from this slot) for a NEMA14-50 outlet as a backup for the UMC if I ever needed it. And filling out the sub-panel I was planning on buying.

Knowing full well that I couldn't charge 3 cars all at once. And that you couldn't fit more than 2 cars in my garage anyway.

Yeah, I should probably correct that section, it's confusing... and with certain interpretations, it's wrong.

Even with a 125A panel you cannot simultaneously operate an HPWC @ 80A and charge at 40A on the 14-50, because your feeder needs to be rated at 150A for that (continuous load rules).

You are correct in that if you expect not to use both at the same time, you may add both circuits there.

 

[ElSupreme]

Yeah, I should probably correct that section, it's confusing... and with certain interpretations, it's wrong.

Even with a 125A panel you cannot simultaneously operate an HPWC @ 80A and charge at 40A on the 14-50, because your feeder needs to be rated at 150A for that (continuous load rules).

You are correct in that if you expect not to use both at the same time, you may add both circuits there.

Thanks! I stumbled upon that (looking to confirm my conduit sizing) and had a second thought.