Thanks to everyone for the clarification on "plug-in" HPWCs - may have to consider that approach for our MX.
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I just bought a standard oven range plug at Home Depot and did the wiring inside the HPWC myself then set the dip switches to 40amps. Easy Peasy!
My only concern there is that oven 14-50 outlets are often wired with 40 amp breakers and #8 wire. That cord you purchased might have #8 conductors when you should really use #6 for a 40 amp continuous load. I'm assuming your 14-50 outlet has been wired with a 50 amp breaker and #6 wire.
Just to be clear - it's perfectly legal and safe to run #8 in conduit at 40A charging (50A required circuit rating) and I wouldn't blink an eye if it were wired as such for permanent installs. If it's NM cable (Romex), it must be #6.
When you are talking flexible cord, there's a different table you have to use. NEC uses table 400.5, which requires #6 flexible cord for 55A with 2 current carrying conductors.
Tesla service said that even though I purchased the HPWC with the car, it is an accessory & has 1 yr warranty. Does anyone have documentation saying otherwise? I bought the car in July 2013.
Me again! I called Tesla Headquarters & they confirmed that back when I bought it, it WAS & IS covered under the 4 yr warranty. They said that policy is different now, but for early adopters, the warranty was different. So he will be calling my SC to inform them. Thanks everyone for the ideas & help.
It is no secret that Tesla's HPWC, and UMC are not engineered well enough to run at their full capacity, 20kw, amd 10kw, respectively. I have said this from the very beginning. You would think that such a crucial part of the cars functionality would be more reliable, and better engineered, but it's not. I have yet to have a UMC last a year(have been through 7 or 8). I don't see that changing, because the fixes have been patches that don't fully address the real issues. It's really painful and sad to watch.I haven't had my car long, but am on my second HPWC. The first one installed fine and worked on all settings EXCEPT 80A. On 80A it would generate 8 red flashes when connected to the car or when using an external J1772 tester. On all other settings it worked fine. My analysis of the failure was too much capacitance in the pilot line and too high of impedance in the pilot drive circuit such that on the very narrow pulse width for the 80A pilot, the EVSE couldn't reliably detect the resistance due to rounding of the square wave.
Tesla promptly sent me a new one, which didn't have the same issue, so I'm happy with service. However the HPWC in my opinion, and I have specific experience designing EV charging systems, is not engineered as well as I think it should be.
For starters, the wiring, fuses and mechanical connections for the 80A current are barely adequate, and embody a lot of resistive losses, so this is why there is a lot of heat generated. Also, the contactor has a 240VDC coil, but Tesla took no steps to reduce coil current after pull in which is customarily done on other large contactors. In fact, the manufacturer of the ones they use in the battery pack sells models with built-in "economizer" circuits, here is the circuit that is built in that performs this function:
View attachment 88473
Doesn't cost much to add, and drastically reduces the heat in the contactor. What's more, is Tesla could have added the economizer function in the HPWC's firmware without the need to add any circuitry! It's often used in EV's to reduce the overhead so you save precious watt-hours instead of wasting them as heat in your coil. In the HPWC, this isn't as important, but the heat component is. Add the heat from both the resistance losses in the high-current path and the coil and you have one hot unit! This thermal cycling is not good for reliability and can hasten oxidation and the loosening of mechanical connections, which causes the problem to spiral out of control and then something burns out. This has happened to many HPWC users!
When I purchased my MS, I tried to purchase the HPWC with the car, and was told by my adviser to just login to my Tesla and order it on the web site. Problem is, they explicitly state "The standard warranty for the Wall Connector is 1 year for over the counter and aftermarket online purchases." There was no option for me to do anything else.
I love my MS, but I must say this is a chicken-**** move on Tesla's part. Clearly they are having a lot of warranty claims. It's also clear to even a layman that the unit gets overly hot, and most people know that heat is the enemy of electronics. I could care less about the warranty if it was superbly engineered, or at least engineered to standard automotive specs for a high-current appliance that is expected to be used daily. In my professional opinion it is not.
My solution is to modify (band-aid) the system as well as practical to ensure it is reliable. There's almost as nothing as frustrating as unreliable transportation, and the HPWC is an integral part of the car's operation.
There's a lot at risk to Tesla right now at this phase in their growth. You wouldn't think they'd be willing to gamble with something as critical and so full of latent liability as a high-power electrical appliance.
Agreed. I don't want to drag this too far off topic, but Tesla really needs to step up, and soon, on these issues if they want to be better than other automakers and continue to hold on to their world-class image.It is no secret that Tesla's HPWC, and UMC are not engineered well enough to run at their full capacity, 20kw, amd 10kw, respectively. I have said this from the very beginning. You would think that such a crucial part of the cars functionality would be more reliable, and better engineered, but it's not. I have yet to have a UMC last a year(have been through 7 or 8). I don't see that changing, because the fixes have been patches that don't fully address the real issues. It's really painful and sad to watch.
1. The Drive Unit problems are probably not that big of a worry, as most of the issues are just noisy DU's due to very wide manufacturing and assembly tolerances. The drive units are also plentiful and cheap used, because Tesla is hostile to owners of salvage(and non-salvage for that matter) cars.Agreed. I don't want to drag this too far off topic, but Tesla really needs to step up, and soon, on these issues if they want to be better than other automakers and continue to hold on to their world-class image.
The 3 biggest things making me uneasy about my MS (and Tesla) are, in order:
1. The drive unit problems. What's going to happen after the warranty?
2. Tesla's failure to give owners basic service info and make parts available for reasonable prices (or at all)!
3. The 12V "Vampire" fiasco. Again, Am I to buy a 12V battery every 18 months and pay for all that wasted electricity?
I have a lot more than those, but those are the biggies. I'll stop now before I get too far OT.