Model S - HPWC (High Power Wall Connector)

[FlasherZ]

Put an insulating bushing on that Romex connector. It's a little plastic piece that screws on top of that locknut to ensure that the connector can't rub/cut insulation on the wire. It's required in most jurisdictions for high-current applications (and a lot of DIY'ers miss them).

 

[linkster]

Thanks, will do!

 

[gpetti]

....... I looked at the breaker box and discovered that my 100 amp breaker had been replaced with a 50 amp breaker that had tripped and was pretty hot. ......... No real explanation from the electrician - other than oops

Got an update today. Apparently the electrician who told me it was just a mistake wasn't the one who changed out the breaker. Turns out that during the electrical inspection, the inspector raised a concern about the 100amp breaker so the electrian who was on site replaced it with the 50amp (nobody told me anything about it - even though it happened a few weeks ago and resulted in downgrading a service I paid for!). I'm waiting for more details but I've been told via my general contractor that the inspector said that for 100 amp car charging there needs to be an interlock with some kind of attic fan?? I don't think I've ever heard anyone mention any such requirement before. Anyone have any clue what this is about?

 

[araxara]

but I've been told via my general contractor that the inspector said that for 100 amp car charging there needs to be an interlock with some kind of attic fan?? I don't think I've ever heard anyone mention any such requirement before. Anyone have any clue what this is about?

Some older EV chargers had an optional fan signal to indicate that the area needed to be exhausted. This was primarily due to the battery chemistry (flooded lead acid) which requires ventilation due to hydrogen formation.

 

[gpetti]

Some older EV chargers had an optional fan signal to indicate that the area needed to be exhausted. This was primarily due to the battery chemistry (flooded lead acid) which requires ventilation due to hydrogen formation.

This is what I was wondering, i.e. if they were thinking of an older type of battery, but I'm hoping I won't need to leap through hoops with the City bureaucracy to be allowed to have a 100 amp breaker.

 

[Mayhemm]

Got an update today. Apparently the electrician who told me it was just a mistake wasn't the one who changed out the breaker. Turns out that during the electrical inspection, the inspector raised a concern about the 100amp breaker so the electrian who was on site replaced it with the 50amp (nobody told me anything about it - even though it happened a few weeks ago and resulted in downgrading a service I paid for!). I'm waiting for more details but I've been told via my general contractor that the inspector said that for 100 amp car charging there needs to be an interlock with some kind of attic fan?? I don't think I've ever heard anyone mention any such requirement before. Anyone have any clue what this is about?

I don't know, Greg, that seems pretty sketchy to me. Maybe you should be on the lookout for a new electrician/general contractor?

 

[Bugeater]

This may well depend on what city, but that was certainly not even imagined when I had my HPWC installed.

 

[FlasherZ]

NEC article 625 deals with it, Tesla is labeled with no ventilation required. You don't need a fan. Inspector should have had his code book with him and looked it up.

 

[gpetti]

NEC article 625 deals with it, Tesla is labeled with no ventilation required. You don't need a fan. Inspector should have had his code book with him and looked it up.

Thanks as ever. I found your FAQ which has also pointed me to the online NEC and other useful gems. If I had to point someone to definitive documentation that states that the Tesla battery does not require ventilation. Is it marked on the battery somewhere or the charger itself?

 

[Cottonwood]

NEC article 625 deals with it, Tesla is labeled with no ventilation required. You don't need a fan. Inspector should have had his code book with him and looked it up.

The NEC is a little pricey, but given the overall cost of some of this work, many may be able to justify a personal, "Kindle" edition of the NEC for $70. At least it's searchable and you can use it on a Kindle, iPad, Laptop, etc. It is really nice that those extra megabytes don't weigh much! Besides when issues like this come up, it's really nice to look this stuff up.

Amazon.com: NFPA 70®, National Electrical Code® (NEC®), 2014 Edition (National Fire Protection Associations National Electrical Code) eBook

 

[gpetti]

The NEC is a little pricey, but given the overall cost of some of this work, many may be able to justify a personal, "Kindle" edition of the NEC for $70. At least it's searchable and you can use it on a Kindle, iPad, Laptop, etc. It is really nice that those extra megabytes don't weigh much! Besides when issues like this come up, it's really nice to look this stuff up.

Amazon.com: NFPA 70®, National Electrical Code® (NEC®), 2014 Edition (National Fire Protection Associations National Electrical Code) eBook

Thanks, my impression from the few versions visible online was that Tesla wasn't specifically mentioned but that it states that the equipment and or vehicle will be marked as not requiring ventilation. That version was from 2011 I believe so possibly 2014 is more specific? From a Canadian standpoint I guess the Canadian Electrical Code is probably what he was following but I'm assuming that wouldn't say anything radically different.
....addendum:
Just looked at the charging unit, the text on the right hand side of the charger is partially obscured in my case by a nearby wall but with great difficulty I managed to snap a picture and it says the following:
- This device is intended only for charging vehicles not requiring ventilation during charging
- Ventilation not required

 

[bluetinc]

Just as some quick background that may help explain things with the inspector. Durring a charger session (via j1772), the car will request charging with ventilation, or without ventilation. After the request, the charger then supplies power. I expect that if a car requests a charge with ventilation, the HPWC would not supply power.

Peter

 

[EVSteve]

Btw, I have no use for this HPWC as it was installed solely to supplement the "Super" network as we have been using a more than adequate 14-30 (always runs cool) for a 160-mile commute (currently at 30K miles).

Been looking through the HPWC posts to educate myself on any potential install issues. Really happy to see I'm not the only person who bought one just so other Teslas could charge quicker lol. I thought I was insane Of course I don't even have a Model-S yet. Still running two Volts. Soon though.

 

[gpetti]

Just as some quick background that may help explain things with the inspector. Durring a charger session (via j1772), the car will request charging with ventilation, or without ventilation. After the request, the charger then supplies power. I expect that if a car requests a charge with ventilation, the HPWC would not supply power.

Peter

Thanks, for some reason I just saw this. In any case I called the city inspectors and found that there didn't seem to be any issue. They said if the manufacturers equipment says it doesn't need ventilation then it doesn't need ventilation. I called the electrician with this information directly (previously I had been talking through the GC) and they agreed to look into it. They later came back and agreed that it didn't seem to be a problem but then identified that the inspector had also complained about the lack of a disconnect switch near the HPWC! This appears to be a valid issue but they only seem to have brought it up now for some reason.
I still haven't seen the inspection report myself so for all I know the ventilation issue was a red herring to try and dissuade me from pushing for the 100A breaker. The owner was away so I raised a bit of hell with the general contractor who originally hired this electrician. When the owner came back he agreed to put things right by the code and re-install the 100A breaker so I'm back to where I should be and they didn't charge me for any additional parts or labor.

 

[Mayhemm]

Thanks, for some reason I just saw this. In any case I called the city inspectors and found that there didn't seem to be any issue. They said if the manufacturers equipment says it doesn't need ventilation then it doesn't need ventilation. I called the electrician with this information directly (previously I had been talking through the GC) and they agreed to look into it. They later came back and agreed that it didn't seem to be a problem but then identified that the inspector had also complained about the lack of a disconnect switch near the HPWC! This appears to be a valid issue but they only seem to have brought it up now for some reason.
I still haven't seen the inspection report myself so for all I know the ventilation issue was a red herring to try and dissuade me from pushing for the 100A breaker. The owner was away so I raised a bit of hell with the general contractor who originally hired this electrician. When the owner came back he agreed to put things right by the code and re-install the 100A breaker so I'm back to where I should be and they didn't charge me for any additional parts or labor.

The whole thing still strikes me as extremely shady. No electrician worth his salt would shove a 50A breaker into a circuit requiring 100A and hope you didn't notice.

Good to hear you're back up and running though.

 

[gpetti]

The whole thing still strikes me as extremely shady. No electrician worth his salt would shove a 50A breaker into a circuit requiring 100A and hope you didn't notice.

Good to hear you're back up and running though.

I agree. I can't help wondering if they substituted the 50 amp breaker to pass the inspection (rather than install the disconnect that they had missed - not sure if they actually thought the ventilation was an issue) and then were possibly going to put the 100 amp breaker back after the inspection, but forgot. I'd like to see the report but I suspect I'll lose interest now that its all working properly.

 

[PhilBa]

The whole thing still strikes me as extremely shady. No electrician worth his salt would shove a 50A breaker into a circuit requiring 100A and hope you didn't notice.

Good to hear you're back up and running though.

I had quite a back and forth with my electrician trying to get an 80 Amp breaker instead of a 50 for my HPWC. Going through my general contractor just wasn't cutting it so I spoke to him directly. He squirmed and finally did it. Passed inspection, too. Been working flawlessly for >12 months.

 

[gpetti]

I had quite a back and forth with my electrician trying to get an 80 Amp breaker instead of a 50 for my HPWC. Going through my general contractor just wasn't cutting it so I spoke to him directly. He squirmed and finally did it. Passed inspection, too. Been working flawlessly for >12 months.

Good to hear it not just me, and not just local electricians.

 

[invisik]

Good to hear it not just me, and not just local electricians.

Yep mine too--they put in an 80, had to make another trip to swap it out for a 100. Did a fine job otherwise, very neat and tidy.

-m

 

[Cottonwood]

I had quite a back and forth with my electrician trying to get an 80 Amp breaker instead of a 50 for my HPWC. Going through my general contractor just wasn't cutting it so I spoke to him directly. He squirmed and finally did it. Passed inspection, too. Been working flawlessly for >12 months.

But why 80 and not the full 100?