eladts
Member
NEMA 10-30 is deprecated and not allowed for new installs. Use NEMA 14-30 if you can spare 30A breaker.
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NEMA 10-30 is deprecated and not allowed for new installs. Use NEMA 14-30 if you can spare 30A breaker.
eladts
Member
The Model 3 will do 16 mph with 240V/20A and 22 mph with 240V/24A according to this table:
https://shop.tesla.com/content/dam/tesla/CAR_ACCESSORIES/MODEL_3/CHARGING_ADAPTERS/Model3_NEMA.png
SageBrush
REJECT Fascism
A question regarding breaker box terminology:
Is 100Amps rated at 120V ?
If so that is 12 kW. It sounds like a fair amount of power if care is taken to spread the consumption around the clock.
My first thought would be to install a 240v 30 Amp outlet so that the car puts a 7.2 kW load on the system and sends about 6.5 kW to the battery. Since around 30 kWh are needed for the car a day, that would work out to ~ 5 hours of charging in the middle of the night when other loads are reduced. A simplified load analysis probably looks like this: of the AC/car/range, run any two at the same time
OP can also hunt down energy hogs like old style light bulbs, and learn to turn off stuff like the computers at night. In my home the only semi-continuous load is the fridge. Everything else is off if not being used.
Is 100Amps rated at 120V ?
If so that is 12 kW. It sounds like a fair amount of power if care is taken to spread the consumption around the clock.
My first thought would be to install a 240v 30 Amp outlet so that the car puts a 7.2 kW load on the system and sends about 6.5 kW to the battery. Since around 30 kWh are needed for the car a day, that would work out to ~ 5 hours of charging in the middle of the night when other loads are reduced. A simplified load analysis probably looks like this: of the AC/car/range, run any two at the same time
OP can also hunt down energy hogs like old style light bulbs, and learn to turn off stuff like the computers at night. In my home the only semi-continuous load is the fridge. Everything else is off if not being used.
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Something to be aware of is that the wiring from the utility transformer to your circuit breaker panel has two parts: one part the utility owns, which runs just to the building, and a second set of wires that you own, from the end of the utility wires to your meter. When I had to add a circuit to charge my car, my electrician said that the utility's "drop" (the wires that run from the pole to the building) were actually capable of 200 amps, even though the wires from there to the meter were only sized for 100 amps. He said that is pretty common in our area and allows the utility to support upgrades to building electrical service without running new wires themselves. So I was able to have him install a second meter with its own set of wires from the where the utility drop connects to the building. The separate meter is for the charger only, in my case. So if your electricians have not addressed that point, you might ask them if you can put in a separate meter for the charger. That way you can put in service for up to 100 more amps without compromising the house service in any way.
galbrecht7
Member
That's interesting. I was curious if I could do something like this with my current situation. I have a detached garage with access from an alley where the utility poles & electric lines are. There's a transformer on a pole just off my garage in the alley. I was wondering if there was any way to just get a completely separate line run from transformer to my garage with its own meter. That's kind of like what you had done, right? Just not coming right off the utility transformer. But it really would be a short run in my case. No electrician has suggested it, I haven't brought it up though. Didn't know what costs would be for something like that, opposed to what I'm currently leaning towards (240 trenched to garage on 30amp breaker for $1500-$2000ish).
In every case I've ever seen where a new meter needed to be installed, the electric company has to be involved (meaning they send in their own technicians to install the meter and do any line upgrades, then you have your own electrician do the rest of the work from there). In the situation that @David29 posted where the incoming line was already capable of 200A service, I would think it's fairly inexpensive. Having to run new lines is where you start looking at a large expense.
galbrecht7
Member
Gotcha. That makes sense. One of the four electricians noticed my meter is a bit newer & he said is capable of 200amp service. Not sure if the wires to my house are 200 though. I guess that's what I would need to inquire about. So then is it just a sub panel with that other 100amp, and a 240 line off that to my garage? I understand why that would be an improved install, to potentially have 100amps dedicated to the garage, but unfortunately I think my install price will remain in the same ballpark. I think the 30 feet of trenching and conduit for the 240 line will keep it similar.
It's not a bad option to explore - you would need to contact your power company to get a real answer. If they can run the line above ground then that would save a lot of the trenching costs.
Right. In my case, there was no cost for utility work. The utility installed the meter once the electrician installed the meter box and after the Town performed the electrical inspection of the finished work. And the utility did not care that it was only for charging my car and was a relatively small load.
But this may also depend upon local utility policies and laws. If I recall correctly, many years ago when I had a house built here in the Boston area, there was no charge for the utility work even though they had to install two poles and run the line about 300 feet from the nearest street. There would have been a cost for three poles or more. So it is worth asking. YMMV
SageBrush
REJECT Fascism
Is there something special about an electric utility trench ? I rented a trencher for $60 when I ran cable for my PV. It took me a good 15 minutes to get the hang of it in addition to a quick tutorial from the rental shop.
No, that's definitely the route I would take if it were me. I was just going off of the prices that were quoted above. Electricians charge outrageous (at least, in my mind) prices for digging trenches.
I was trying to say that if the electric company can run a new line from one of the poles above ground, then he wouldn't have the pay the thousands of dollars quoted above to run the line underground from the house to the garage.
eladts
Member
The feed of most residential installations is split phase, so it is 2 × 100A × 120V = 24kW.
SageBrush
REJECT Fascism
Conduit is also cheap to buy, and in my PV case I ran the wires too. I just let the electrician connect the wires to the end terminals (inverter/disconnect/breaker box).
There is a trick to getting wires through long run conduits. I think they call it a conduit mouse or something close (and nicely descriptive
)Google knows.
Just be sure to get your known underground lines mapped out before you trench, and don't be too surprised if you cut an unmapped line of something. I cut a sewage line and some 12v lines to my sprinkler system. Each were easy fixes and would have happened regardless.
Addendum: I was wrong -- the trencher rental was $88
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SageBrush
REJECT Fascism
Thanks, but if that is the case I don't really understand why 100Amps is much of a limit for most people. Just wire for 240v and have enough breakers ... no ?
voip-ninja
Give me some sugar baby
Conduit is also cheap to buy, and in my PV case I ran the wires too. I just let the electrician connect the wires to the end terminals (inverter/disconnect/breaker box).
There is a trick to getting wires through long run conduits. I think they call it a conduit mouse or something close (and nicely descriptive
Google knows.
Just be sure to get your known underground lines mapped out before you trench, and don't be too surprised if you cut an unmapped line of something. I cut a sewage line and some 12v lines to my sprinkler system. Each were easy fixes and would have happened regardless.
Addendum: I was wrong -- the trencher rental was $88
Normally it's referred to as a 'wire snake' or 'fish tape'. It's a flexible thin steel rod on a reel that you can use to run wires through conduits and other spaces.
It has a hook at the front for tying things to. You can also get a cable lubricant to make the cables easier to push through the conduit. Apply liberally, it's designed not to be conductive or damage the insulators or other materials it comes into contact with.
SageBrush
REJECT Fascism
Definitely not anything special. Just need to know the required depth. Could also easily do PVC conduit if you know requirements. Likely needs to be inspected prior to filling trench.
It's expensive for an electrician because they have to rent the trencher (assuming smaller company), pick it up, drive it there, deal with any unknowns (bolder or concrete in the trench path), return the trencher, etc. Lots of time and risk to them.
If you trench yourself, must call whatever local number to have underground utilities marked.
This is what we do with our leaf. It works fine if you don't drive much every day. When we do, we can pick up a few groceries and use the fast charger there or just settle for a lower charge the next morning. In that case we plug in between trips (usually don't do this) and get a full charge the next morning.
This install is just a hold over until new house, which will have the Tesla Wall Connector. No reason to install that into a temporary situation.
Panel from parking is 10 yards. However, it is through the house, so one two rooms in between. Would snake the wire into the attic and go to garage that way.
Since I drive 104 miles a day, assuming I just go to work and home, 75 miles a day will not be sufficient. But it seems the 30amp breaker would be sufficient recovery.
Night time charging would be fine even on a higher amp breaker. The only things running at night would be occasionally HVAC, fridge, and 3d printer. No longer have non-LED bulbs, so all the normal easy efficiency gains are exhausted.
