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Wire type

selaing

Member
Aug 6, 2020
21
3
Oregon
Going to change out my 8 gauge wire for 6 gauge and change breaker from 40amp to 50 amp.

Outlet is 19 inches (yes - less than 2 feet) from the Electric Panel.
Should I use single wire or bundle jackets romex wire? If single wire, do I need to use conduit for that short of distance?

already have my 14-50 plug.

cheers
 

jcanoe

Active Member
Oct 2, 2020
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Maryland
If the wire is exposed then it should be in conduit.

If you plan to use the Gen2 Mobile Connector with the NEMA 14-50 power plug adapter the Mobile Connector will limit the charging to 32A. It does not make a difference whether you have a 40A or 50A breaker installed as the Gen2 Mobile Connector is limited to maximum of 32A. The Corded Mobile Connector (a separate product) will support up to 40A when used with a 50A circuit.

The NEC permits use of the NEMA 14-50R with a 40A circuit. Just label the receptacle as 240V/40A to avoid any confusion for someone assuming that the circuit has a 50A breaker.

If the existing 8 gauge wire is exposed it should be installed in conduit.
 
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jcanoe

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Oct 2, 2020
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When you state the existing wire is in a jacket is it metallic clad wiring? Why not post a photo so it is easier to understand what you currently have to work with for the new receptacle.
 

selaing

Member
Aug 6, 2020
21
3
Oregon
1623962113202.png
1623962113202.png
this is what I currently have in the wall. Thinking since going thicker to
1623962182727.png
 

jcanoe

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Oct 2, 2020
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What does or did the existing circuit power? Is there a receptacle or just a junction box?

What do you currently use or plan to use to charge the Tesla Model Y? Is this the Standard Range Model Y or the Long Range or Performance Model Y. It makes a difference as far as maximum charging rate.
 

selaing

Member
Aug 6, 2020
21
3
Oregon
the outlet is 2 feet from the breaker box. It has a 14-50 outlet (receptacle) in the box. Looking at long range and probably a juice box or something to increase KW.
 

jcanoe

Active Member
Oct 2, 2020
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Maryland
Consider that if this is a new 50A circuit then per the 2017 revision of the NEC the circuit breaker needs to be a 50A GFCI breaker (~$100)

For less than what the JuiceBox 40A EVSE will cost you could purchase the Tesla Wall Connector ($500). When you hard wire you don't need to use a GFCI circuit breaker (saves you $100.) The Wall Connector can be used on any of 15/20/30/40/50/60 amp circuits. If you perform a load calculation you may be able to install a 60A breaker, then the Wall Connector can enable charging at up to 48A. When used with a 50A circuit the Wall Connector enables charging at up to 40A (same as the JuiceBox 40.)

If you determine that the existing service can support a 60A breaker the wire would need to be 4 gauge not 6 gauge.

As the distance from the panel is less than 2ft. I would cut out a section of the drywall and then run the wire you need using NM-B (no conduit required if inside the wall) for the circuit. the drywall can be screwed and glued back in place then taped, spackled and painted.
 
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Sophias_dad

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Jul 29, 2018
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Massachusetts
In the wall its gotta be in a jacket(NM-B) or conduit. Individual conductors not-in-conduit is not allowed.

NM-B is not rated to carry 48 amps continuously(i.e. for EV use) at 6AWG, sadly. It sounds like you plan a 50 amp breaker, which is fine, but don't expect any pluggable-ev thing to take more than 40 amps because that's all the outlet(or more precisely, the plug/connector) can allow continuously.

For simplicity, I'd stick with the NM-B, but only if its in a wall.
 
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selaing

Member
Aug 6, 2020
21
3
Oregon
thanks Canoe
you now threw out another wrinkle.... If existing service can take 60amp.... I am unsure how to tell. I do have 200amp service. I do want to plan for the future, and we all don't know what chargers will be in a few years. I did add up all my breakers and have:
17 - 20 amp, 9 - 15amp, 3 240 40 amp, 1 240 50 amp and 1 30 amp
 

jcanoe

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Oct 2, 2020
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Maryland
thanks Canoe
you now threw out another wrinkle.... If existing service can take 60amp.... I am unsure how to tell. I do have 200amp service. I do want to plan for the future, and we all don't know what chargers will be in a few years. I did add up all my breakers and have:
17 - 20 amp, 9 - 15amp, 3 240 40 amp, 1 240 50 amp and 1 30 amp
I don't know. It seems like your service may already maxed out. Someone who knows more than I do needs to take it from here.
 

Sophias_dad

Supporting Member
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Jul 29, 2018
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Massachusetts
I did add up all my breakers and have:
17 - 20 amp, 9 - 15amp, 3 240 40 amp, 1 240 50 amp and 1 30 amp

You really need to do a load calculation, there's no telling what all those devices are, but I can guarantee you they aren't all running at a significant portion of their ratings all the time.

The big ones to be mostly concerned with are the 240 volt loads, but even the 120's count for something. Its all a question of worst-case but reasonably likely loads. For instance, if one of those 240 volt loads is a bunch of electric heaters and another is a big AC unit, the smaller one can be ignored. At the same time, if you go and look at the actual ratings of all those 240 volt loads, you are likely to find they take considerable LESS than the breaker ratings when running normally.
 

selaing

Member
Aug 6, 2020
21
3
Oregon
thanks all for your help. here is breakdown of 240:
kiln 40 amp 240 - breaker being replace for EV charger (would charge during night)
Heat pump (AC only) 40 amp 240 - Not on year round just hot time in Eugene.... few weeks. hardly at night
Wall oven 40 amp 240 - on during the day and near night, but never during the night
Dryer - 30 amp 240 - on during the day
Hot tub - 50 amp 240 (pump runs all the time, but only on during the day)

So out of this list.... car would only thing really draining from 10 pm - 6 am.
 

jcanoe

Active Member
Oct 2, 2020
3,469
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Maryland
Have you considered how many miles per day you drive, on average, to see whether the existing 40A circuit (enables charging at 32A) would meet your needs? Charging at 32A my Model Y adds 25 to 27 miles of range per hour of charging. I rarely need to charge for more than 3 hours. Just saying.
 

selaing

Member
Aug 6, 2020
21
3
Oregon
that is the interesting thought too.... miles per day will be less than 15 once we go back to work (working from home right now).

Is it better to charge slow and steady than rapid and quick?

I could just keep everything as is.... 40 amp with 240 and 14-50 receptacle.
 
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TBrownTX

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Dec 25, 2020
880
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Dallas, TX
I went with the Wall Connector. I came through a stud into the side of the box via a knockout and used a fitting to secure the wire. I used NM-B Romex. It's important to use #4 wire vs #6 if you go NM-B with a 60 amp breaker.

Here's the wire I used:
https://www.lowes.com/pd/Southwire-...-Non-Metallic-Jacket-Wire-By-the-Foot/3334032

If you use 4/3 wire you will not need the neutral wire, mine is capped using heat shrink tubing. It could be used later to swap for a 14-50 plug. Some choose to use the neutral for the ground instead.

IMG_1996.jpeg
IMG_2009.jpeg
 

jcanoe

Active Member
Oct 2, 2020
3,469
3,518
Maryland
that is the interesting thought too.... miles per day will be less than 15 once we go back to work (working from home right now).

Is it better to charge slow and steady than rapid and quick?

I could just keep everything as is.... 40 amp with 240 and 14-50 receptacle.
At Level 2 (240V) and up to 48A it hardly matters as you are charging at well below 1C, closer to .1C. Charging at 120V is less efficient so you would want to charge at 240V and any or 20/30/40/50 amp circuits. Since you already have the 40A circuit and wiring complete I would just use that and see if you really need to upgrade to a 50A or 60A charging circuit.
 

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