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240 in the garage. cost?

rjpjnk

Member
Mar 12, 2021
403
162
NJ
What do you guys think about Tesla's statement that an external disconnect switch is not recommended?
Could it really be they just not want the wifi to be off? What other reasons could there be?
 

M3BlueGeorgia

Active Member
Dec 10, 2018
1,375
1,083
Atlanta, GA
Yes run the 6 gauge wire. You don't want to have to rerun the wire.

However, given you only have a 100A supply, I suggest using only 20A until you get that upgraded.

So start out with a 240v/20A breaker and a 6-20 outlet. It'll charge at around 14 mph.

If you find you need higher charging capacity, upgrade to a 200A panel and switch to a 6-50 outlet.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
6,271
7,324
Boise, ID
What do you guys think about Tesla's statement that an external disconnect switch is not recommended?
Could it really be they just not want the wifi to be off? What other reasons could there be?
I'm pretty sure it's much more simple than you are thinking. It's just not necessary, and putting in the disconnect is two more sets of terminations of wires screwed into lugs, which is more potential problem/failure points in the connection chain where something may not be installed well or fastened in tight enough. It's more reliable to just have uninterrupted wire than going through the switch. With high current things, you just want as few junctions as possible.
 
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jcanoe

Active Member
Oct 2, 2020
2,173
2,150
Maryland
The NEC requirement is that if something is OVER 60A, then it always does require a lockable disconnect. For 60A and below, that is not required by NEC. But there are sometimes some state or local requirements for it for these lesser levels.
I just had a new HVAC system installed at my home this month. The old gas furnace and AC compressor were over 35 years old. The AC compressor is wired to a 240V/30A circuit breaker. There was an old galvanized metal service disconnect box (badly rusted) mounted on the side of the house close by the AC compressor. The installer noted that he installed a new disconnect while connecting the new AC compressor. This is in Maryland.
 

Gauss Guzzler

Member
Dec 27, 2020
209
260
Thousand Oaks, California
NEC 2017 requires a disconnect switch for chargers *over* 60A but some people misinterpret that to include 60A so Tesla is clarifying in case your electrician doesn't know. They're likely advising against it to discourage people from using inadequate switches or flipping them excessively.
  • "625.43 Disconnecting Means. For equipment rated more than 60 amperes or more than 150 volts to ground, the disconnecting means shall be provided and installed in a readily accessible location. The disconnecting means shall be lockable open in accordance with 110.25."
Air conditioners have switches because they need routine service and it's very unlikely for the homeowner to be messing with them. For car chargers there's no reason to have a switch, only risk.
 
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Peelz

Budding EV fanatic.
Apr 10, 2021
222
367
SE Iowa, the armpit.
Update:

I did call in the pros. lol And, being that my security cameras have just gone offline, they're installing it right now. :)

I asked about the 100 amp service vs charging at night at 32 max amps... no problem. I said id probably set the car to do it less, around 24.

6 gauge, 14-50, with 50 amp breaker. about 25 ft of wire.

quoted me "around 500" ill be pleased with that, definitely worth paying someone with knowledge to crawl in the attic and fish wires through the wall and between other high voltage wires

Im sure I could do it, but it would take forever and it would look like crap. Also, its a 50k dollar car, not a junky old dryer, which Ive wired before....
 

Peelz

Budding EV fanatic.
Apr 10, 2021
222
367
SE Iowa, the armpit.
As long as you have room or can make room for a double pole breaker your 100A main is likely fine and it's completely normal to have the branch circuit breakers add up to way more than the main. If your electrician or inspector insists that a 50A breaker will be a code violation you can step down as low as 30A with the wire you already have, but if you go below 40A you'll need a 14-30 instead of 14-50.

Don't sweat it and don't get sucked in by all the electricians (and TMC posters) who insist that a bigger panel is somehow better. If you get this all done and you're tripping the main just lower your charge current a little, you can set it to whatever you want. If that proves unsatisfactory *then* you can upgrade the panel. But really, the charger only uses 32A at max power, it's not some huge load that's going to overwhelm your electrical system, it's more like installing a second oven.

This was the opinion of the electrician. I asked about maxing out the main breaker... he said MAAAYBE. if you run oven, ALL your lights, your air compressor, and the AC and charge the car ALL while you're running the hot tub(cheap kind not a big one)

Those scenarios wont happen.

:)

Suppose I over-thought it, then over bought supplies for it. lol but It'll work. Plan was to have a friend do it for me while I help but I don't have time and my knowledge is maybe a half step above layman.


Being that is overbuilt, should we REALLY get into ev's, well maybe its ready for wall charger or something else that can pull more.


Again, after reading all the posts, which I appreciate, I think it was missed that I had already called pros to do it.
 

Peelz

Budding EV fanatic.
Apr 10, 2021
222
367
SE Iowa, the armpit.
Peelz, Is your installer using a GFCI breaker?

I'm told the mobile charger has one in it so I don't think so but I will find out when I get home. He did mention he didn't use the 50 I had bought to my wife but not why or what he replaced it with..


Started at 8, and They're all done already. see, wasn't that worth it? LOL I would have spent ALL DAY AT LEAST on it.

now I just need a damned car! hahhaahahahahah
 

rjpjnk

Member
Mar 12, 2021
403
162
NJ
Yeah, it's hard to wait...

Keep us posted on what you find when you get home and how you like it.

I am leaning towards the Wall Connector myself, and started a new thread here to compare costs vs the outlet option. I am really liking the WC option.
 

jcanoe

Active Member
Oct 2, 2020
2,173
2,150
Maryland
The GFCI built into the Mobile Connector (Wall Connector too) is designed to protect the user when plugging and unplugging the charging connector from the vehicle's charging port. The GFCI circuit breaker, where required, provides protection when plugging and unplugging the NEMA 14-50 plug from the receptacle. (Turning off the power at the panel before plugging or unplugging the NEMA 14-50 plug from the receptacle is even safer, makes the GFCI circuit breaker of questionable benefit.)
 
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Peelz

Budding EV fanatic.
Apr 10, 2021
222
367
SE Iowa, the armpit.
The GFCI built into the Mobile Connector (Wall Connector too) is designed to protect the user when plugging and unplugging the charging connector from the vehicle's charging port. The GFCI circuit breaker, where required, provides protection when plugging and unplugging the NEMA 14-50 plug from the receptacle. (Turning off the power at the panel before plugging or unplugging the NEMA 14-50 plug from the receptacle is even safer, makes the GFCI circuit breaker of questionable benefit.)

the mobile charger will be plugged into the garage receptacle 99% of the time, and only used to charge the car every other day or 3 days. Then removed to take on trips(but even then Ill lean towards SC's) So thats what I was thinking.

Yeah, it's hard to wait...

Keep us posted on what you find when you get home and how you like it.

I am leaning towards the Wall Connector myself, and started a new thread here to compare costs vs the outlet option. I am really liking the WC option.


We may eventually go that way too. That was the advice I got that made me decide on 6 gauge and then the 14-50. Just thinking ahead. Id rather have too much, so if we DO upgrade we're ready.

but for now, learning the way of the EV, the included mobile charger will do for our lifestyle. She commutes 40 miles per day. wont need to charge outside of home often...

I look forward to that learning.

related side note, I went to just now purchase the 14-50 mobile adapter, and theyre out of stock LOL Guess its good I have at least a month to wait for the car. :)
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,271
7,324
Boise, ID
Peelz, Is your installer using a GFCI breaker?
I'm told the mobile charger has one in it so I don't think so but I will find out when I get home. He did mention he didn't use the 50 I had bought to my wife but not why or what he replaced it with..
And then there was more discussion about what it does and why that's of little benefit, which is all true. But I'm here to just tie up these loose ends, that the real reason is just because code requires it. That was added to code in 2017, that ANY outlet being installed for the purpose of EV charging must use a GFCI breaker. It's a stupid requirement, but it's there.
 
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frankvb

Supporting Member
Feb 29, 2020
876
544
San Diego, CA
I've got a 100A panel, and charge (usually at night) at 40A (on a 50A circuit). No problem at all. Entire house draws less than 4A during the night hours (without A/C or charging). A/C would draw less than 20A.
 
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Peelz

Budding EV fanatic.
Apr 10, 2021
222
367
SE Iowa, the armpit.
And then there was more discussion about what it does and why that's of little benefit, which is all true. But I'm here to just tie up these loose ends, that the real reason is just because code requires it. That was added to code in 2017, that ANY outlet being installed for the purpose of EV charging must use a GFCI breaker. It's a stupid requirement, but it's there.
well Iowa all but disavows the mere existence of EV's (At least teslas) so there isn't squat for that code. at least in my little town lol YET.

4 ft from the ground, no exposed cables.

Unless that's what he meant and went and got a GFCI. like I said, ill find out.

Thanks folks I appreciate all your insight.
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,271
7,324
Boise, ID
well Iowa all but disavows the mere existence of EV's (At least teslas) so there isn't squat for that code. at least in my little town lol YET.
That is irrelevant if Iowa likes or supports EVs. It's in the versions of NEC starting with the 2017 version, and guess what? Iowa has adopted an even newer version. They are on the 2020 release. So yeah--it's in there.
 
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jcanoe

Active Member
Oct 2, 2020
2,173
2,150
Maryland
And then there was more discussion about what it does and why that's of little benefit, which is all true. But I'm here to just tie up these loose ends, that the real reason is just because code requires it. That was added to code in 2017, that ANY outlet being installed for the purpose of EV charging must use a GFCI breaker. It's a stupid requirement, but it's there.
What about NEMA 14-50 receptacles used for powering an RV, wouldn't it make sense to require a GFCI protected 14-50 receptacle to protect the operator of an RV when plugging in and unplugging a motorhome?
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,271
7,324
Boise, ID
What about NEMA 14-50 receptacles used for powering an RV, wouldn't it make sense to require a GFCI protected 14-50 receptacle to protect the operator of an RV when plugging in and unplugging a motorhome?
Yes, that absolutely would make more sense, which is why this requirement only for electric vehicles is ridiculously stupid and does not make sense.
 

jcanoe

Active Member
Oct 2, 2020
2,173
2,150
Maryland
Yes, that absolutely would make more sense, which is why this requirement only for electric vehicles is ridiculously stupid and does not make sense.
I recall that the owner's manual for my ClipperCreek EVSE states that you should always turn off the power to the circuit whenever plugging in or unplugging the EVSE from the receptacle. I admit that I haven't always turned off the power at the panel when plugging/unplugging; the 14-50 receptacle is located inside my garage and I'm not standing in a puddle of water.
 

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