Electrical Wiring in the Home/Tesla car wiring



I need an outlet for Tesla car like this that requires 50 amp

but eventually will be upgraded to 100 ampm sevice
I was wondering if if the wire for both is the same and if I need a 100amp service braker will work for 50 amp and what is best to install now? Thanks

You are killing me,  I tried to figure a way into a Tesla,  after all I have repaired and designed three phase motors forever,  and the Tesla technology is so pure and straight forward it is beyond imagination,    sometime if you find  minute you have to tell me about the car and your experience.

Now to your question, with a question.  Why not skip the 50 amps and go for the 100 right away?  My guess is you are shy of power from your existing main?

Any chance you will be doing the majority of the charging at night?

If there is a way you can make sure you are not using maybe just a few devices while charging you might be able to adjust your loads to allow for the 100 without much fuss at all.

It just seems likes a waste to do 50 now and 100 later.

I think that answers your question,  but if not  YES   just like anything else,   a swimming pool pump on 110 that draws 10 amps  will draw 5 on 220,  however contrary to many fables, 220 does not save on POWER  it does allow for smaller wire, boxes and so on,  but POWER IS POWER.

The advantage of charging the batteries with twice the current is time. Period.

I was hoping I could show you a way to start with 50 then add another wire in parallel and avoid replacing the entire station,    and you can partially.

If you look closely at the different cords,     http://shop.teslamotors.com/collections/charging    The plug that fits the car is the same on all of them.

It looks like adding another cable to the car plug would be a trick,  BUT if you start with the 100 amp plug  and cord   but only feed it 50 amps [40] constant I see no reason that will not work, until you get the FEED side with enough amp space to let the 100 flow,  in the meantime only 50 will flow down the 100 OEM cable but that is fine,  

See the different wire sizes that go into the same car end plug?  More amps bigger cable but the same end,  electrically and physics speaking you can always go larger on the wire with less amps,  then when you get more amp capacity,   you already have the larger OEM end.

I would check with Tesla, I am sure they want to sell a million chargers, but talking real world   all they are doing is down sizing the wire to the car plug to fit the amp capacity,  get my point?

So you are thinking the correct way, but partially,   when you eventually have 100 amps flowing you will need twice the cable size for 50, and you will need the breaker dedicated to 100 amps,   what I don't know is if the charge rate is built into the regulated charging station which is a glorified battery charger.

I would think at some point at partial discharge even with the 100 amp max the charger will slow down the flow rate to something 50 or even under as the batteries become charged,    

Now all I read is for people who are clueless about the whole process, but what I see with my own eyes is larger wire in the same car end plug,   

so if you have had the 100 amp charger now,   but only 50 worth of capacity,  I don't see why the 100 amp charge would not charge at a rate as high it could.  

If so you plug the 100 amp charger and cable set, into a 50 amp breaker until you get new a new service entrance,      now I don't know what Tesla would say, but think about a normal car charger.    If your typical battery is charging it charges at the max amps the charger will allow,        and then tapers off as the battery becomes fully charged,       

That would save you from buying two chargers,   granted you are only going to get what you provide it,  but I bet the 100 amp setup will charge at 50 [40 cont]    then when you get the other 50 you just up the breaker and plug it in.

Obviously they have 'universal" pigtails    so up to that point I know I am correct.

Now at the unreal prices for these chargers  I am not sure if they would come clean with you or not,  or even though it would or could never hurt a thing according the laws of physics,  they are selling these things, they could current limit the actual charger but I doubt it,   maybe they would even suggest buying the 100 amp now and do exactly as I suggest,   but with the costs you have in all of this  I would verify it with them,      

I see no harm at all using the 100 amp on a 50 breaker if all the breaker is fed at the moment is 50 amps,    I know this is confusing, but the charger limits or controls the rate of charge even on many cheapo walnart chargers,      

So if you could avoid spending $4000 for one 50 then reselling it or getting what you can for a used charger,  you would save several thousand,   


The forum above helps explain,  one of the subjects is backwards though,  if you had a 100 amp circuit that tried to draw 100 amps a 50 amp breaker would trip,    I'm saying the opposite,  put wire that is big enough for 100amps,   but you only have 50 now,  so you have double the capacity you need,    the wire can be a foot in diameter   and even if it is shaved down at the ends,  it fits the lower 50 amps,   then when you get 100 amps of service   cut the wire off where it was shaved down to fit the smaller breaker and you got it,      

You might want to write me at my personal email and we can go over this,  vbut I just spent an hour researching this and no where do I see a problem with wiring forward,  if you will,  and then when you get the other 50 you dont have to buy a whole new cord,    that has the very same car end on it,  just bigger wire,  
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Will Babbitt


Electrical issues of all types, wiring, control, appliances, components, specialty in Electric MOTOR or APPARATUS trouble shooting, electric motors, electrical problems, single phase, three phase, DC, capacitors, elevator MG-Sets, modifications, reverse engineering, VFD Drives, single to three phase convertors. Repair of most any electrical/mechanical/electronic apparatus, OEM, AC, DC, Industrial Applications, Three phase, single phase failure mode, determining the root cause of the equipment failure BEFORE failure repeats, Antique appliances, electric motors, fans, ceiling fans, base mount fans, poor equipment performance, Modifications, habitual failures, vibration, redesign, obsolete issues, collectible items restored, rewinding. Owner of EMR Repair Inc www.emrrepair.com More information on electric motors, under Engineering/Motors Ask about any electrical or mechanical problems in the home, office, or even at your work. B2B or business to business CONSULTING I can do but it would be a much more complex issue, that would require a significant amount of time. repair@mearservice.com from there we can discuss and begin work on about anything. Industrial electric motors, controls, troubleshooting, vibration, alignment, any type of industrial or commercial electric/electrcical equipment For the home owner, renter, apartment if you have odd things going on, describe to me, photos are normally very helpful, appliances, heating and air conditioning issues, light switches, installation, DIY PROJECTS FOR THOSE NOT EDUCATED IN ELECTRICAL, we can do some things, but for safety and sanity reasons, I may refer you to a local electrician, and help you find one, help you with pricing and even speak directly with anyone you hire if you have issues,


Over thirty years with a major repair and sales company, VP of Operations, and former owner of my own specialty repair shops, MEAR Services local to Kansas City Missouri EMR Repair Inc., located in Kansas City Missouri, 2014 sold both businesses to JCI Industries, Lee's Summit Missouri wbabbitt@jciind.com Evaluation and repair of electrical/mechanical apparatus. Electrical and mechanical repairs, trouble shooting including, vibration and balance issues. About.com provides this service, and the huge costs to provide help on about any subject. They provide the servers, the people to vet the experts, costs that would be the same as operating a good sized business, They should be appreciated for what they do, the huge costs and the great help they provide for free, Electric motor questions, can be answered here but there is a dedicated category that has other experts to help and add to a solution. Other common questions, are noises in the walls, breakers tripping, devices not starting or shutting down for no apparent reason, smoke alarms buzzing, thermostat change outs, or sizing wire or needing information for a new project, but anything can be resolved, anything, with enough effort and patience, DIY, with electrical is possible, but in most cases the use of a simple ohm meter or volt meter is needed, they can be purchased at any hardware store for a few bucks. If you have smoke, or smell smoke, don't be writing me, call 911 the Fire Department has no problem looking for smoke smells, better then spraying water on a blazing fire. DO NOT GET CAUGHT INVESTIGATING AND TRAPPED IN A BASEMENT LOOKING FOR A BLOWER FAILING< As to the tip jar, it is up to you, it is appreciated, every expert spends out of pocket that I know, we spend on IP time, computer wear, printing documents, books, and of course our time, but if we prevent a $400 service call, we did well,

Former IBEW, EASA, IEEE, UL, ..............


10 plus years, various Technical Schools, followed by Industrial College Credit and non Credit Courses, electronics courses, experience in most any electrical apparatus, electric motors and generators, AC OR DC, fractional to above 5000HP, other electrical apparatus, slip rings, sleeve [plain] bearings, lubrication, identification-no data plate, control components, service and sales. I have continued night schools for decades, the list is extensive. I have been in the business of repairing most anything with wires or mechanical parts for decades, I have some helpful hints and directions you won't have to dig up. Or hopefully not have to pay a huge service call invoice to find.

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