Limited to 50A - ordered with a HPWC - what to do?

[SamGarber]

I ordered the Model S with a HPWC, but now found out from my electrician that my house electric can only support 50A more. I do want the twin chargers, but kind of wondering what the benefit would be of having a 14-50 outlet installed versus actually connecting up the HPWC. Kind of hard to justify $2500 for just having a spare cable in the trunk. I don't think it charges faster via HPWC @ 50A? I saw on the forums somewhere that Tesla might take back the HPWC and credit some of the money?

Any and all help is appreciated!

Sam.

85 kWh | Grey | Tan Leather | Obeche Matte | 19" Primacy | Tech Pkg | Parking Sensors | Fog Lights | Parcel Shelf | Body Colored Roof | Air Suspension | HPWC | Ordered 8/22/13 | Confirmed 9/1/13 | Delivery Date pending | #?????

 

[qwk]

Tesla will take back the HPWC, and give you back your money.

 

[yobigd20]

My HPWC has been sitting in its original packaging for the last 6 months. NEMA 14-50 is way more than plenty. Haven't decided what to do yet with the HPWC.

 

[SamGarber]

Thanks! I am getting a second opinion just in case - SolarCity does not service my area any more, so they recommended MrElectric, who apparently has done 5 Tesla charger installs in the last week alone!

I guess that King of Prussia mall store is really generating some traction in the Philly area...

If I can get the HPWC going at 80A inside my garage, I might see how much extra a 14-50 outlet outside might be for the occasional guest PlugSharer.

Sam.

85 kWh | Grey | Tan Leather | Obeche Matte | 19" Primacy | Tech Pkg | Parking Sensors | Fog Lights | Parcel Shelf | Body Colored Roof | Air Suspension | HPWC | Ordered 8/22/13 | Confirmed 9/1/13 | Assembly Date: 10/7/13 | Delivery Date: ~10/15/13 | #?????

 

[Sparrow]

One slight advantage of the HPWC is that the cord is 5 feet longer. Also isn't the $2500 price for dual chargers (in the car) and the HPWC? The HPWC by itself is worth about $1200.

 

[AmpedRealtor]

If you ever find yourself without sufficient charge and need to head out, you'll be glad you had an HPWC because it charges at double the rate of a NEMA 14-50. A NEMA 14-50 only makes sense if you anticipate charging at night because at 30 miles per hour of charge, it will take over four hours to charge to 50%.

 

[efusco]

If you ever find yourself without sufficient charge and need to head out, you'll be glad you had an HPWC because it charges at double the rate of a NEMA 14-50. A NEMA 14-50 only makes sense if you anticipate charging at night because at 30 miles per hour of charge, it will take over four hours to charge to 50%.

Just to be clear, the HPWC only charges at twice the rate of a NEMA 14-50 if it's wired to 100amp service. If he wires his HPWC to 50 amp he gets the exact same as with the NEMA 14-50.

 

[SamGarber]

Yes, exactly efusco! I am not sure what the HPWC buyback price is from Tesla considering they do include the second charger, but I will definitely consider returning if my second opinion consult with MrElectric will tell me that all I can have is the 50A.

 

[ZBB]

Just to be clear, the HPWC only charges at twice the rate of a NEMA 14-50 if it's wired to 100amp service. If he wires his HPWC to 50 amp he gets the exact same as with the NEMA 14-50.

And the car needs twin chargers too... Single charger and a 100amp HPWC also results in the exact same speed as a NEMA14-50. Keep that in mind if charging at a Tesla store or some of the (few) high amp J1772s out there...

 

[efusco]

Yes, exactly efusco! I am not sure what the HPWC buyback price is from Tesla considering they do include the second charger, but I will definitely consider returning if my second opinion consult with MrElectric will tell me that all I can have is the 50A.

Selling it here or elsewhere online is an option for you if you decide against it. Just would add, it's:
1)Nice to have the UMC in the car at all times
2)Nice to have a nice looking wall mounted charger
3)The cord is more rugged than the UMC and you avoid unnecessary wear and tear on your UMC. Obviously, a second UMC is an option too.

I suspect that you can get 100amp service if you're willing to pay for it, but as others have pointed out, it's rarely necessary. As you're in Philly, you should have a plethora of charging options for any trips you might want to take, including superchargers, so a rapid top up would be a rare thing in all likelihood.

 

[SteveW25561]

To add to efusco's benefits:
Having the HPWC means you always have a charging cable which can't be stolen, or jiggle loose from the wall. I like its elegant design.

In my situation I only have it on a 60 amp breaker just to utilize that second charger, but would have been ok even at just 50A since I didn't want to schlep my UMC around.

Btw mine is installed outside so I also wanted to avoid plugging and unplugging from the wall when it rains.

 

[SamGarber]

Steve, what are you getting out of that 60A as far as actual charge speed? I just got the quote from my regular electrician and he quoted $700 (without the permit) for the 60A 240V installation with the HPWC. I am waiting for Mr. Electric to see what they say - but if they quote some outrageous price to do 100A I might just go with the 60A...

 

[Puyallup Bill]

If you can not use the HPWC, Tesla will take it back. Following is text I received from ownership after I complained about bundling the HPWC with dual chargers.

Hi William,

I received your note this morning regarding our new option to bundle the High Power Wall Connector and Twin Charger feature.

We made this decision in clarify for customers the benefit Twin Charger feature offers, and what it requires. Fortunately, under the circumstance that a customer cannot install the Wall Connector, we will accept a return of the device. This is the only work around we have currently, but I’ll investigate if we can add the Twin Charger into the configuration manually, without addition of the Wall Connector.

Thanks for sending us the suggestion. If you have any other questions, feel free to contact me.


Best Regards,
William Masterson | Ownership Experience Advocate
3500 Deer Creek Rd. | Palo Alto, CA 94304
p 877.79.TESLA (877.798.3752) | e [email protected]

 

[Beaker]

To add to efusco's benefits:
Having the HPWC means you always have a charging cable which can't be stolen, or jiggle loose from the wall. I like its elegant design.

In my situation I only have it on a 60 amp breaker just to utilize that second charger, but would have been ok even at just 50A since I didn't want to schlep my UMC around.

Btw mine is installed outside so I also wanted to avoid plugging and unplugging from the wall when it rains.

One more benefit is that with the HPWC you can keep the portable cable in the trunk thus preventing you from driving off on a trip and leaving it behind.

 

[Lloyd]

If your panel is limited to 50 amps, you could put a 60 amp breaker with the HPWC, charge at 50 (80% of continuous) and be able to charge 20% faster than the UMC!

 

[AmpedRealtor]

My house could not "technically" handle another 100A breaker for my HPWC, but I didn't let that stop me! After doing a load calculation, Solar City/Mr. Electric said my panel could only handle an extra 50A by the time you take safety margins into account, etc., and it would cost $5,000 to upgrade my house service to allow for an HPWC on a 100A breaker. However my electrician - also my solar installer and very experienced - laughed when I told him that. He said it's not ever going to be a problem because most people rarely, if ever, max out their power usage at any given time. He said if I ever turned on every light in the house, my oven, all four burners of my electric cooktop, fired up the clothes dryer, the spa heater, both pool pumps while running both AC units full blast, I should turn my HPWC down to 50A in the vehicle.

I don't know your particular situation, so please don't take the above to be general advice. However, if you are in a similar situation and you're not able to handle a 100A breaker due to a load calculation that factors 100% simultaneous usage of all your home's systems (plus a 20% safety margin), perhaps you can discuss your usage patterns with your electrician to see if you can work around your apparent limitations and still get that 100A breaker. It hasn't caused me any problems.

 

[Dave EV]

If your panel is limited to 50 amps, you could put a 60 amp breaker with the HPWC, charge at 50 (80% of continuous) and be able to charge 20% faster than the UMC!

No, that's technically not allowed. If his panel only has 50A of room on it, that means he can only put a 40A continuous load such as EV charging on it.

 

[Lloyd]

Don't think that is correct. If he has done the load calc, and he has 50 amps left, he can use 50 amps. FLASHER!!!! HELP!!!

No, that's technically not allowed. If his panel only has 50A of room on it, that means he can only put a 40A continuous load such as EV charging on it.

 

[FlasherZ]

Don't think that is correct. If he has done the load calc, and he has 50 amps left, he can use 50 amps. FLASHER!!!! HELP!!!

:biggrin:

Load calculations must consider 125% of continuous load. NEC 215.2(A)(1) for feeders, 215.3 for overcurrent protection. So yes, if the load calculation determines that the existing load calculation is 50A lower than the main breaker size, you can only add a 40A continuous load.

- - - Updated - - -

He said it's not ever going to be a problem because most people rarely, if ever, max out their power usage at any given time.

Load calculations take this into account by using some assumptions about total loads... while you can stretch it for the reason you mention, electricians are supposed to use NEC article 220 calculations to size things appropriately and retest them when adding circuits. Some choose not to, figuring that you will have some oversubscription. Who knows when you'll run into that case, though.

Here's a good overview:
Residential-Service-Calculations-in-the-National-Electrical-Code

 

[brianman]

If your panel is limited to 50 amps, you could put a 60 amp breaker with the HPWC, charge at 50 (80% of continuous) and be able to charge 20% faster than the UMC!

Math check: 40 -> 50 is 25% faster.