questions about home charging set up.

[ralph142]

So far I've been charging on a 120 volt 15 amp gfi circuit in my garage. That works ok for my daily needs, but the gfi trips about 50% of the time when the garage door opener is used. Nothing else is on the circuit, unless I'm playing with tools.

Its hard to expand to a 50 amp dedicated circuit because the breaker box is physically full, although well below the 200 amp service. It turns out that the garage circuit is on a 20 amp breaker and has 12 gauge wire, but the outlets are all 5-15s.
So I wonder as a quick and simple (i.e. within my skill set) change can I splice in a 5-20 outlet between the box and the gfi outlet so as to pull 18 amps for charging without the circuit gfi, or would that be something irredeemably stupid and against code ? Around here anyway no need for a permit or inspection for this change.

As an aside the whole structure will be remodeled over the winter and I'll have a dedicated wall charger (or two) added, so this is temporary, but would be a nice increase in charging speed and convenience for the next 8 months.

 

[Silicon Desert]

You probably know that almost every situation is unique and that code varies from city to city. I'd call an electrician to give you a free quote on what you need and while they are there, they will likely fill you in on what might be any problems.

 

[SSedan]

I would look into if there are double stack breakers available for your box and do a simple dedicated 20amp for the car or at that point you could do a smaller 240volt circuit.

 

[Leopold Stotch]

Using the 3 prong Tesla adapter will not allow the full potential of the 20A wall outlet. The adapter is configured to software limit the car as if plugged into a 15A outlet. Car doesn’t know the difference. Based on adapter used, not house wiring.

 

[Leopold Stotch]

Might be good to get an electrician in and have them assess these three options (or they may have better idea).
1. Add sub-panel
2. Add 40A outlet tie off of another 40A breaker using a load splitter that will only allow one to be used at a time
3. Upgrade main panel.

Option 2 - I was quoted around ~$1200 for my particular setup.

Also, know the difference between an estimate and a quote. Get a quote if you can.

 

[ralph142]

Using the 3 prong Tesla adapter will not allow the full potential of the 20A wall outlet. The adapter is configured to software limit the car as if plugged into a 15A outlet. Car doesn’t know the difference. Based on adapter used, not house wiring.

there is a 5-20 adapter available from tesla for $35

 

[ralph142]

yep, all good advice, thanks. As I said, the whole garage is due for a remodel in the winter, so wall chargers going in then. This is temporary, and if it works as I suggested above it will cost about $10 in parts.

 

[SSedan]

If the panel is in the garage I bet you can put together a 240volt solution pretty cheap. Bet you could do it for $50 and while it won't pay for itself will save a few bucks in electricity as it will be more efficient running the charging hardware a shorter time.

The first year I had my car I used a 14-30 outlet I put below the panel for the cost of the outlet since my car came with that adapter and I had 4 ft. of 10gauge Romex from another project. Think the outlet cost me $8 and I had a disused baseboard heat circuit it repurposed the breaker for.

Tandem breakers are like $10, the 40amp to use your 14-50 adapter is another $10, Home Depot sells wire by the foot 6-3 looks like $2.15 a foot, so about $50 would let you buy both breakers, outlet and 5ft of wire and you would have them should the wall connector ever crap out.

When I was younger I wasted a LOT of money trying to do things cheap as possible. These days I will spend a few bucks extra on convenience, a 240volt solution will mean not having to make sure you plug in so often or a quicker recovery when getting home from a long trip.

 

[ewoodrick]

So far I've been charging on a 120 volt 15 amp gfi circuit in my garage. That works ok for my daily needs, but the gfi trips about 50% of the time when the garage door opener is used. Nothing else is on the circuit, unless I'm playing with tools.

Its hard to expand to a 50 amp dedicated circuit because the breaker box is physically full, although well below the 200 amp service. It turns out that the garage circuit is on a 20 amp breaker and has 12 gauge wire, but the outlets are all 5-15s.
So I wonder as a quick and simple (i.e. within my skill set) change can I splice in a 5-20 outlet between the box and the gfi outlet so as to pull 18 amps for charging without the circuit gfi, or would that be something irredeemably stupid and against code ? Around here anyway no need for a permit or inspection for this change.

As an aside the whole structure will be remodeled over the winter and I'll have a dedicated wall charger (or two) added, so this is temporary, but would be a nice increase in charging speed and convenience for the next 8 months.

Since the garage door is on the circuit, you won't be able to switch to 240V. GFCIs are notorious. If the GFCI is on the breaker, then while it may not be up to code, some folks have been known to swap out with non GFCI circuit. Note, this can be dangerous, as the GFCI is expressly installed to keep moist concrete floors and 120V for interacting with each other through a person.

If a 20A breaker is in place, it will probably be acceptable to swap the 15A Duplex outlet with a 20A single outlet. Garage doors are decent size motors and if you have the car plugged in and the door starts to close, there could be a tendency to trip the breaker, dependent on the door opener requirements.

It's the playing with the tools that becomes the bigger issue. That's definitely starts to be an issue with removing the GFCI and swapping the outlet over to 20A. Dependent on the tools and how big they are and how often you play with them, you may be overloading the circuit. If you only have one wall plug and one ceiling plug, then switching the wall plug to a single 20A outlet is still probably okay. But if you have multiple wall outlets, overloading becomes a succinct possibility.

You may want to just call an electrician out to see about switching the outlet and/or installing a new circuit. If you can get them to come out and quote it, you may find the information that you need. But they will probably be hesitant to quote switching out a plug (I can swap the plug faster than quoting it)

 

[SoundDaTrumpet]

Swap the offending GFCI outlet with a newer one. Maybe you are due for a new opener.

 

[woodguyatl]

So far I've been charging on a 120 volt 15 amp gfi circuit in my garage. That works ok for my daily needs, but the gfi trips about 50% of the time when the garage door opener is used. Nothing else is on the circuit, unless I'm playing with tools.

Its hard to expand to a 50 amp dedicated circuit because the breaker box is physically full, although well below the 200 amp service. It turns out that the garage circuit is on a 20 amp breaker and has 12 gauge wire, but the outlets are all 5-15s.
So I wonder as a quick and simple (i.e. within my skill set) change can I splice in a 5-20 outlet between the box and the gfi outlet so as to pull 18 amps for charging without the circuit gfi, or would that be something irredeemably stupid and against code ? Around here anyway no need for a permit or inspection for this change.

As an aside the whole structure will be remodeled over the winter and I'll have a dedicated wall charger (or two) added, so this is temporary, but would be a nice increase in charging speed and convenience for the next 8 months.

Have you tightened all of the wire to your outlets? The one that the garage door is plugged into will sometimes come loose to due to vibration from the opener. Also, GFCI's wear out especially in a garage where they see more temp and humidity changes.

 

[eprosenx]

So far I've been charging on a 120 volt 15 amp gfi circuit in my garage. That works ok for my daily needs, but the gfi trips about 50% of the time when the garage door opener is used. Nothing else is on the circuit, unless I'm playing with tools.

Its hard to expand to a 50 amp dedicated circuit because the breaker box is physically full, although well below the 200 amp service. It turns out that the garage circuit is on a 20 amp breaker and has 12 gauge wire, but the outlets are all 5-15s.
So I wonder as a quick and simple (i.e. within my skill set) change can I splice in a 5-20 outlet between the box and the gfi outlet so as to pull 18 amps for charging without the circuit gfi, or would that be something irredeemably stupid and against code ? Around here anyway no need for a permit or inspection for this change.

As an aside the whole structure will be remodeled over the winter and I'll have a dedicated wall charger (or two) added, so this is temporary, but would be a nice increase in charging speed and convenience for the next 8 months.

Please post pictures of your panel such that we can see where it is located relative to the place you might want an outlet. Then also pictures that let us see and read all the breaker sizes. Then the panel schedule of what breaker is what. Plus pictures of all stickers on the inside door etc they tell us what breakers allowed and what all the specs are.

As others have said, if the circuit is a 20a breaker and 12 gauge wire then you can swap one receptacle to allow the sideways prong of a 5-20. That along with the Tesla $35 5-20 adapter for your UMC Gen 2 may be a decent performance bump.

You might consider swapping the GFCI our for a new one. They do go bad. Some Tesla tripping issues have been solved by going to an Eaton GFCI (but you are describing garage door issues).

I believe the GFCI units that are sold are all capable of 20a even if they only have 15a 5-15 receptacles on the front. So you can daisy chain 5-20 receptacles downstream of them (check me on this by looking at the specs).

If you go this route, your solution may be as simple as swapping the single GFCI receptacle with a new one and at the same time with a new one with the ability to accept a 5-20 plug. That may kill two birds with one stone. Or you could swap both the GFCI and one downstream receptacle where you actually wanted to plug in.

I personally would want some kind of 240v charging option even for the short period until you remodel. I generally can find some creative solution if I can see the panel. Up to and including disconnecting something else that is not critical (like a wall heater that is unused, or a dryer that is now gas, etc...)

Oh, and you can only charge at 16a on a 20a circuit just FYI... 80%

 

[ralph142]

I was just schooled up on the wonderful new invention: tandem breakers. Turns out I can swap out several standard 15 amp breakers on bedroom light circuits for tandems and put in a 50 amp breaker to run a NEMA 14-50 or a Tesla wall connector with no issues. I plead stunning ignorance. Thanks for all the suggestions.

 

[eprosenx]

I was just schooled up on the wonderful new invention: tandem breakers. Turns out I can swap out several standard 15 amp breakers on bedroom light circuits for tandems and put in a 50 amp breaker to run a NEMA 14-50 or a Tesla wall connector with no issues. I plead stunning ignorance. Thanks for all the suggestions.

Note that not all breaker panels support tandems in all breaker positions. This is generally documented on the sticker on the panel door. If you post a picture here we can help you interpret it.

 

[ivan801]

Tandem breaker is a great option. Also, if the breaker AND wiring is rated for 20 A (you will need 12 AWG wire), just swap the outlet for a new GFI 20 A outlet. It has been documented here that new, high-quality GFI outlet usually solves the issue of GFI tripping.

You will probably increase your charge rate by about 50% if you go from 15A to 20A outlet, especially when it is cold. Don't forget to order Tesla plug for 20A outlet, it runs $35.

 

[ralph142]

Note that not all breaker panels support tandems in all breaker positions. This is generally documented on the sticker on the panel door. If you post a picture here we can help you interpret it.

Its a Siemens Model # P2040B1200CU, 20 space, 40 circuit main breaker load center, all the slots are rated for tandem breakers (big learning last night from my brother in law, lol). I'll probably replace the gfi outlet (a little mousing around seems to show people replacing old ones with Eaton brand gfi) and run a new 50 amp to a 14-50 outlet as well for now.

It looks to me like the builder was just cheap were he could be, the next size up box at lowes is $30 more for 40 spaces.