DanCar
Active Member
I 110 charge and don't have a problem. Occasional super charging is fine. I don't see a reason to upgrade. I don't even bother charging at home some times.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Looking for some wisdom for choosing 75D vs 100D
- Thread starter xilex
- Start date
We struggled between the 75D vs 100D earlier this year. A couple of more things to consider if you are purchasing a Model S.
When we purchased in May, the 100D was being offered by Tesla with a 1.5% interest rate on financing which was was a considerably lower rate than the 75D at the time. Not sure what the comparison is today but I think the Model 3 somewhere in the 3.4% area so the 75D is somewhere near that.
We also had our original MX owner advisor hunt for a discounted inventory car with low mileage and she found the Stanford Palo Alto showroom floor MS100D became available with a $12,400 discount (it had 24 miles on the odometer).
So in the end, the MS100D may have cost us $3-4K more than the equally equipped 75D. Your mileage may vary but it pays to shop.
When we purchased in May, the 100D was being offered by Tesla with a 1.5% interest rate on financing which was was a considerably lower rate than the 75D at the time. Not sure what the comparison is today but I think the Model 3 somewhere in the 3.4% area so the 75D is somewhere near that.
We also had our original MX owner advisor hunt for a discounted inventory car with low mileage and she found the Stanford Palo Alto showroom floor MS100D became available with a $12,400 discount (it had 24 miles on the odometer).
So in the end, the MS100D may have cost us $3-4K more than the equally equipped 75D. Your mileage may vary but it pays to shop.
henderrj
Active Member
Nuts, I was afraid someone would ask that! I'll try to take them and post it tomorrow.
henderrj
Active Member
Both grounds go to the green ground, both Commons obviously together. Then one black each side from each extension cord. The sensor to show 220-volt when you plug it into proper 110 plugs go also one on each side. Couldn't be simpler! By the by, you're on your own here, if you burn up your house don't complain to me!
Attachments
henderrj
Active Member
I'm not exactly sure what the disagree means. That you don't think it's a good idea? You think it's unsafe? You just don't think people should do this sort of thing? It would be interesting to know your thoughts.
mknox
Well-Known Member
It can be very dangerous. When you charge from a normal 240 volt outlet, the circuit is supplied from a ganged 2-pole breaker and if there is an overload or other problem, the breaker will trip and open both hot legs. When you use the 120 volt combiner, you are picking up two legs 180 degrees out of phase to make up 240 volts leg to leg, but each branch leg is on a separate breaker. Also, you don't know what other 120 volt loads are on each branch circuit and could end up with an unbalanced situation. In the event of overload or other trouble (caused by car charging or some other plugged in appliance, only one of the two separate 120 volt breakers will trip, leaving the other leg "hot".
henderrj
Active Member
I guess I assumed that was obvious. I also believe people are not idiots. But even if they are they should be allowed to shoot themselves in the foot if they want!
And "very dangerous". Remember, both lines are both hot all the time as a normal rule. If one side goes dead all you have out of the ordinary is no car charging and a dead line.
Last edited:
I regularly take road trips to San Diego from Orange County on our X75D. It’s about 180mi round trip. I drive about 70-80mph and typically supercharge for about 10-20 minutes each trip. It would be great to have a 100D to skip charging but not worth the almost 20k premium for us. I would easily pay a 10k differential though!
mknox
Well-Known Member
And a possible shock hazard because you still have a live leg on what appears to be a dead 240 volt circuit. You could also have a high resistance fault to ground on the leg that doesn't trip, depending on the nature of the failure, presenting an overheat or fire situation. Plus, it also violates electrical safety codes and may negate your home insurance should a problem arise. It's when something doesn't go to plan that problems can arise.
henderrj
Active Member
So then you agree? If a person wants to shoot himself in the foot he should be allowed to do so?
And, as to a live leg on a possibly dead 240-volt circuit, like I said, if you're an idiot, you should still be allowed to do what you want. Do you actually know someone who puts their fingers on an outlet without checking first if it's dead or not?
As far as backfeeding, that would mean the charger that is plugged in would have to feed it back. I don't think any UL listing will allow a 240-volt to feed cross phases like that. Maybe I'm wrong.
How about the fact that if you plug in one side and then walk around with the other plug looking for an outlet on the other leg (or even if anyone unplugs one side before the other) then you are holding a male plug that is exposed electrified metal.
henderrj
Active Member
Don't think you looked very closely. That can't happen. Well, unless some idiot wired the house wrong in the first place. Hopefully you'll have taken care of that before you try something like this!
mknox
Well-Known Member
Sure... as long as you're doing this on your own property where all the risks are yours and yours alone. I certainly wouldn't recommend using such a Frankenplug on someone else's property.
Without putting too fine a point on it, I've been in the electrical industry for almost 40 years and seen how things not done to code can quickly go sideways. I cannot in good faith be seen as endorsing something like this in a public forum where others might interpret it as a "good idea".
Don TLR
Active Member
Ran into a guy recently who upgraded just to miss a charger and buy the 100. He regularly did t trip from Durango to Boulder and would have to stop at a level 2 charger just to make it with the smaller battery (like I did) in this long stretch. The 4 corners area lacks chargers making the bigger battery very helpful..
Looks very interesting. It seems to be pretty idiot proof, as long as you know understand that the "Frankenplug" is live, even if one breaker trips. Other than that, are there any serious risks if the power of the power being significantly out of phase on two circuits within the same home? If so, are there serious risks beyond voltage drop? And just like henderrj said, is backfeeding even a risk on the UMC??
If you are undecided after all this wisdom perhaps wisdom is not what you seek.
You want the 100D, get the 100D.
Console yourself with "in 20 years the 75D will have too short a range". Or some other nonsense.
You want the 100D, get the 100D.
Console yourself with "in 20 years the 75D will have too short a range". Or some other nonsense.
mknox
Well-Known Member
I don't think this is "nonsense". The OP was simply looking for opinions and there are lots of good ones either way. Just look at the suggestions that seem to fit your personal objectives and go from there. Not everyone's personal objectives and requirements are the same.
henderrj
Active Member
If you are coming off the same breaker panel, almost a certainty in most homes of America, there would be no possibility of being out of phase, no. In fact, I'm not sure what the deal is with even worrying about one line being live. You still can't get to it unless you plug something in. Of course you wouldn't be able to charge then, but I don't think that would be any worse off than you were otherwise.
mknox
Well-Known Member
Most North American homes are single phase. 120/240 volt split-phase to be precise. The utility transformer has two windings on the secondary side which are each 120 volts on the same phase with the 60 Hz sine waves 180 degrees apart from each other. This creates one leg at a full +120 volts to ground while the other is a full -120 volts. Together they are 240 volts leg to leg.
But... some residential properties are supplied via a 120/208 volt 3-phase, 4-wire distribution systems with 2 of the 3 phases plus neutral into each home. Common in apartments and condos but not unheard of in other areas such as townhouse developments and even some single family subdivisions. Here, each phase is 120 volts to neutral, but because the phases are 120 degrees out of sync, they combine to create 208 volts.
To clarify: console your self with nonsense. i.e. you really don't need a reason.
Nothing to do with my advice to the OP to go ahead with the 100D except he need not "justify" it.
