Call your electric company well ahead of delivery if you have twin chargers

[Ceilidh]

Hey all, just wanted to share with you something that PG&E just let me know.

About 2 weeks ago I contacted them to let them know I was getting an EV and would be changing my rate plan as a result. They then had me talk to someone who asked if I was getting the 10 kW charger or the 20 kW twin charger option.

Turns out that during peak times if you have 20 kW running it is likely to overload many standard transformers on top of electric poles. They had to come inspect mine and indeed the transformer on the pole behind my house must be upgraded. They are now booked out to February to do this work.

They cover the expenses for this, of course, since it is their issue and not my personal property. The advice they gave me in case the car comes between now and the transformer fix is only charge off peak until it is fixed.

Now, I will try and do this as much as possible, but I work all hours and sometimes will need to charge during the day while I sleep during the day. I guess I will have to limit the draw from the HPWC until PG&E upgrades their equipment.

I had not heard of this before so I wanted to let you all know well ahead of time.

Cheers.

 

[Trnsl8r]

Thanks, good tip.

Now, just to clarify, this would only apply if you're getting the HPWC, correct? Since that's the only time in a home environment that there would be a difference between using single or twin chargers? With 14-50 there shouldn't be a difference is that I'm thinking...

 

[FlasherZ]

Correct.

You should also call the power company even with a 14-50, if you have only 100A service or less into your home, for the same reason.

 

[ckessel]

They are now booked out to February to do this work.

If you charge at the full 70amp during the day and blow their transformer, I suspect it'll get replaced sooner... :wink:

 

[strider]

Yeah, if you want to switch to the E-9 TOU rate they'll force you through an engineering evaluation.

 

[Ceilidh]

Yeah, if you want to switch to the E-9 TOU rate they'll force you through an engineering evaluation.

that's exactly how all this started. I love the idea of blowing their transformer to make them fix it quicker. Just wish that wouldn't leave me and my neighbors without power and potentially set fire to our trees... alas.

And yes, it only applies if you have both twin chargers and the HPWC, or something like your own 1772 at 70 amps or something like that, and then only during peak hours.

Cheers.

 

[cinergi]

If you charge at the full 70amp during the day and blow their transformer, I suspect it'll get replaced sooner... :wink:

LOL (literally). Terrible.

Max is 80 amps BTW.

 

[JakeP]

Does the same concern exist for Padmount transformers feeding a 200 amp service? Perhaps I should call just to be on the safe side.

Padmounts are the green boxes for underground distribution, as opposed to buckets on overhead poles.

 

[FlasherZ]

Does the same concern exist for Padmount transformers feeding a 200 amp service? Perhaps I should call just to be on the safe side.

Padmounts are the green boxes for underground distribution, as opposed to buckets on overhead poles.

The problem with pad transformers is that they all share the same form factor. The 10 kVA, 15 kVA, 37.5 kVA, 50 kVA all look the same. Mine has a big blue number on it since they upgraded it.

And yes, you do need to be concerned. The transformer feeding my 200A service for my home was a 15 kVA (rated ~60A), although the PoCo noted you can typically stretch them pretty far. I called the power company to tell them I'd frequently have another 80 amps on it. They noted that they had measured 197% of rated capacity at some points, and 80A more would likely give them fits. They replaced the wire (now 350 kcmil compact conductor replacing the former 2/0), transformer, meter base, and meter. I took the opportunity to put in a transfer switch, move circuits, and install a generator.

 

[JakeP]

Thanks FlasherZ, I will look for the kVA rating tomorrow, but will call them nonetheless.

 

[Robert.Boston]

Calling your utility is excellent advice. I called my Maine utility, got a surprisingly informed and articulate rep who was able to confirm that my charging won't cause any issues with their equipment.

 

[sublimaze1]

If you charge at the full 70amp during the day and blow their transformer, I suspect it'll get replaced sooner... :wink:

ROTF and LMAO !!!

 

[JakeP]

I called my electric distribution company and received a call back the next day. Sounds like I am OK, I have a 50kVA pad xfrmr feeding a 200A service over 4/0 service line. Adding a 100A subpanel with wire out to the garage for HPWC (and perhaps a temporary NEMA 14-50 on a 50A breaker before the HPWC arrives).

Of course, the majority of the call was me answering questions about Model S, its capacity and charge times, and the Tesla Supercharging network.

Now I need to do the same thing at my parent's house over in Ohio, maybe just installing a NEMA 14-30 over there, if they have room for it in their panel. Hopefully the adapters will be available by the time the car arrives!

 

[dsm363]

Now I need to do the same thing at my parent's house over in Ohio, maybe just installing a NEMA 14-30 over there, if they have room for it in their panel. Hopefully the adapters will be available by the time the car arrives!

If you have to do the installation anyway and their panel can take the load, maybe a 14-50 might work better. You can always dial down how much you draw but at least you could use the included adapter and not have to buy anything else. Glad your house is good to go.

 

[JakeP]

Yep I would definitely prefer a 14-50, but I don't know how much room I have to work with, so I am preparing to scale back. I am typically always there for an overnight or even all-day stay, and they are only 100 miles from home, so even 18 miles/hr of charging is sufficient.

 

[Ceilidh]

If you have to do the installation anyway and their panel can take the load, maybe a 14-50 might work better. You can always dial down how much you draw but at least you could use the included adapter and not have to buy anything else. Glad your house is good to go.

Rumor has it that you can make your own adapters for far cheaper than TMC has priced them in the past.

I most certainly was not up until 03:00 AM doing this last night. And I most certainly did not slip with a screwdriver and gouge my hand tightening screws doing the same.

Having a little "swiss army" bag of adapters can sure streamline things if you start with 14-50 female ends and have male plugs for the most common household and RV park high voltage / high amp plugs. I was a scout as a kid (I have since broken all ties with them for their bigotry, but that is off topic) so I have a tendency to overdo "be prepared" for the sake of safety. You never know when you may REALLY wish you had that other plug someday...

Of course, if you are never going anywhere other than home, work, and grocery store this may not be necessary. But we have a few years before the superchargers are more available for road trips, and even the available j1772 plugs in the wild are usually a pretty darned low 30 amps if you are mid trip. Having something that fits whatever you have as your best option at your overnight or all evening destination can make the difference between needing an ICE vehicle for the trip or being able to use your Tesla.

I may need to be more concerned than most here with a 60 kWh battery, though.

Cheers.

- - - Updated - - -

Yep I would definitely prefer a 14-50, but I don't know how much room I have to work with, so I am preparing to scale back. I am typically always there for an overnight or even all-day stay, and they are only 100 miles from home, so even 18 miles/hr of charging is sufficient.

Where are your folks? I went to college at Oberlin...

Cheers

 

[Lloyd]

Back on topic, I tried to notify PG&E today of my increased usage. They wanted me to sign a form indicating that I would be responsible for engineering fees etc., and wanted me to be on an EV rate, even though they said verbally there would be no fees, and I could keep my rate. I said no thank you and left. So much for trying to help them out!!

 

[JakeP]

My Penn Power guy was very appreciative that I had called to notify them. I was wondering if they would try to hit me with fees or a visit, but there was none. He was mostly concerned with determining if they had an Engineering standard in place to support a 70A / 20kW charger setup (they didn't appear to have one yet).

 

[Ceilidh]

Lloyd that's crazy. They have been by my house twice and I have not had to sign anything. That doesn't even make sense because they are responsible for everything until it touches your house. Totally bizarre. You may want to try talking to a different person. I have had none of these types of discussions with them and they have been very friendly and appreciative that I let them know in advance.

Cheers

 

[Lloyd]

I will go by the Field office directly. I was talking with customer (non) service.