Regular 120 Outlet Question

[Pharmduq64]

Ok so I have read through many threads, and I guess looking for a little clarification. Before anyone comments, I am planning on a NEMA 14-50 installed, just getting quotes and things move slowly in NoVA. I have a new MYP (just picked up Sunday).

I have a single outlet in my garage (outside of the two on the ceiling for the door openers). Unfortunately the way the home is built it is on the same circuit as the master bath and a central GFCI. I had the car plugged in and wasn't thinking, I also had a power strip on the same outlet. Was getting 9/12a. Removed the powerstrip and it seems to be getting pretty steady 12/12a (currently 106v, but was at 110v last night). It did drop to 9/12a once, seems to be holding at 12/12 now.

This is a very temporary solution, obviously not ideal, but until I get the 14-50 done, it's what I got.

Any major concern here? I'm only going 30 miles or so each day. I get home at 5 and plug in till 6am, so it meets my daily needs. I have the car set at 80% max.

Secondly, I have two vacations planned, one for 3 days, and one for a week. Wanted to get thoughts on leaving the car plugged in vs just letting it sit unplugged. I can definitely supercharge it before both trips and have it set to what the group thinks is best. But since it will be plugged in on this unreliable solution, we may not have the NEMA done by the week long trip, I feel comfortable with it at night, but a week scares me. Don't want to hurt the car, or have some wiring issue in the house.

Thanks team! Sorry for being a newbie here.

Car is awesome by the way!

 

[Sophias_dad]

Lets see...

You don't even need a 14-50. Just keep doing what you are doing, just don't use a hair dryer in the master bath while charging. For your needs, you could schedule charging to start at midnight or 1 am every night and you are unlikely to collide with MBR usage.

Up to you if you leave it plugged in or not. With such short trips the car won't discharge much. It also wouldn't hurt to leave it plugged in all the time.

 

[Pharmduq64]

My concern with leaving plugged is if it drops to 9a, from what read that isn't good. And again it's not a super old home, but that wiring wasn't really intended for a continuous draw all the time.

If the consensus is that it won't hurt the car to leave it unplugged for 7 days, I would feel better just in case there is an electrical issue, or it dropped to 9a or something.

As far as the NEMA is concerned, that is more piece of mind for me. Dedicated run, and in a pinch should I need to charge more, I can just do it at home.

 

[DanDi58]

My concern with leaving plugged is if it drops to 9a, from what read that isn't good. And again it's not a super old home, but that wiring wasn't really intended for a continuous draw all the time.

If the consensus is that it won't hurt the car to leave it unplugged for 7 days, I would feel better just in case there is an electrical issue, or it dropped to 9a or something.

As far as the NEMA is concerned, that is more piece of mind for me. Dedicated run, and in a pinch should I need to charge more, I can just do it at home.

Tesla recommends leaving the car plugged in whenever you’re not driving. Leaving it unplugged for that time period won’t hurt it. Just turn off Sentry Mode and the Cabin Overheat Protection to minimize drain while you’re away.

 

[Pharmduq64]

Thanks everyone, appreciate the input.

How concerned is everyone about the Amp drop. It seems to be really random. If I unplug and plug back in it goes to 12a. And last night it stayed at 12a all night. But then every once and a while it will go to 9a.

I guess what is the harm to car and house. Based on my highly regarded degree in electrical engineering from TMC, it seems the drop is that the car detects some irregularities (in my case most likely a large circuit) and dials things down to protect car and home.

Correct?

 

[PDX-Y]

Presumably the car will draw less if it thinks the voltage is dropping from load. Though if you're seeing a drop like that when drawing 12A (on a 15A circuit) I'd be very surprised your breaking isn't tripping first. You might want to make sure the breaker is actually working. And yes, it's likely a dedicated circuit would fix that. Thought it's also possible that your house or neighborhood is seeing brownouts too, which isn't something individual circuit wiring can fix.

 

[Sophias_dad]

Thanks everyone, appreciate the input.

How concerned is everyone about the Amp drop. It seems to be really random. If I unplug and plug back in it goes to 12a. And last night it stayed at 12a all night. But then every once and a while it will go to 9a.

I guess what is the harm to car and house. Based on my highly regarded degree in electrical engineering from TMC, it seems the drop is that the car detects some irregularities (in my case most likely a large circuit) and dials things down to protect car and home.

Correct?

That 12A is actually already dialed back to 80% of the circuit rating or even less. I don't know what your breaker is, but its perfectly legal and actually fairly common to have multiple 15 amp outlets hanging off a single 20 amp breaker(using 12 gauge wire).

There's no chance of harm to the car. Its designed to reduce current as needed.

There's very little chance of harm to the house. The car is just reacting to voltage drop(most likely) either because of other loads on that circuit, in your house, or even down the street. See if you can catch the voltage displayed when it changes to 9 amps.

I'm pretty sure if the outlet is overheating(assuming you are plugging directly into the outlet with the UMC adapter), there will be a message displayed on the cars screen that says "Hey, your outlet is overheating, so we reduced the charge current so your house doesn't burn down. You're welcome."

 

[jcanoe]

Ok so I have read through many threads, and I guess looking for a little clarification. Before anyone comments, I am planning on a NEMA 14-50 installed, just getting quotes and things move slowly in NoVA. I have a new MYP (just picked up Sunday).

I have a single outlet in my garage (outside of the two on the ceiling for the door openers). Unfortunately the way the home is built it is on the same circuit as the master bath and a central GFCI. I had the car plugged in and wasn't thinking, I also had a power strip on the same outlet. Was getting 9/12a. Removed the powerstrip and it seems to be getting pretty steady 12/12a (currently 106v, but was at 110v last night). It did drop to 9/12a once, seems to be holding at 12/12 now.

This is a very temporary solution, obviously not ideal, but until I get the 14-50 done, it's what I got.

Any major concern here? I'm only going 30 miles or so each day. I get home at 5 and plug in till 6am, so it meets my daily needs. I have the car set at 80% max.

Secondly, I have two vacations planned, one for 3 days, and one for a week. Wanted to get thoughts on leaving the car plugged in vs just letting it sit unplugged. I can definitely supercharge it before both trips and have it set to what the group thinks is best. But since it will be plugged in on this unreliable solution, we may not have the NEMA done by the week long trip, I feel comfortable with it at night, but a week scares me. Don't want to hurt the car, or have some wiring issue in the house.

Thanks team! Sorry for being a newbie here.

Car is awesome by the way!

Have you determined if the circuit is wired for 15A or 20A? (This will be clearly labeled on the circuit breaker or GFCI circuit breaker.)

If this is a 15A rated circuit you should only charge at 12A if there is nothing else besides the Tesla Mobile Connector plugged in and running on the circuit. Otherwise use the 8A setting on the Tesla Charging screen. (If you determine that this is a 20A circuit then you should be able to charge at 12A with no issue.) As you stated, several times charging amperage dropped to 9A. This is an indication that the circuit should not be used to charge at 12A.

If the garage door opener is on it's own circuit (either 15A or 20A) an unconventional, temporary solution, would be plug the Mobile Connector into the overhead outlet even if it means using an extension cord (this would have to be a quality extension cord of at least 14 gauge but preferably 12 gauge, 25 ft or 50ft but not longer.) The plug end of the extension cord would need to be secured so it will not pull down on the receptacle and pull out.

As for leaving the Tesla parked at home for up to a week, even longer I would suggest charging to ~80% and leaving the vehicle unplugged. If you leave Sentry Mode, Summon and Advanced Summon (Summon is a FSD feature) turned off at the home location the battery will lose ~1% of charge per day. (A suggestion was made to turn off Cabin Overheat Protection. This feature is only active for 12 hours after the Tesla vehicle has been parked, so it will not run longer than 12 elapsed hours unless you first use the Tesla app to unlock, relock the vehicle assuming you left the Tesla vehicle locked in the garage.)

Although a small risk leaving any EV or plug-in hybrid vehicle plugged in when there is a chance or ground strike lightning nearby is not a risk I like to take. That is another reason to leave the vehicle unplugged for the upcoming vacation days.

 

[Rocky_H]

Some other brands of short range electric cars are actually set by default to only use 8 amps, because they are assuming regular use on normal shared circuits like that. And that's about what I would do in your case--use 8 or 9.

How concerned is everyone about the Amp drop. It seems to be really random.

It's certainly not random; it's because of this:

Was getting 9/12a. Removed the powerstrip and it seems to be getting pretty steady 12/12a (currently 106v, but was at 110v last night). It did drop to 9/12a once, seems to be holding at 12/12 now.

You saw voltage down at 106V at one point. The heavy draw is sagging the voltage down, and the car will detect that much drop and reduce the current to 3/4 of what you were trying to use, which is why it went to 9A.

 

[jcanoe]

Installing a NEMA 14-50 receptacle is one option but installing the Tesla Wall Connector may be a better option.

The 14-50 install has some additional costs that do not apply when installing the Wall Connector:

1) 14-50 receptacles used for charging an EV now require a GFCI; a 50A GFCI circuit breaker costs ~$100
2) 14-50 uses three wires plus ground wire. The Wall Connector only requires two wires plus ground, potentially saving you ~25% of the cost of the wire.
3) 14-50 requires a receptacle box ($10); A high quality 14-50 receptacle from one of the better manufacturers (Hubbell, Bryant or Cooper) costs ~$80
4) The Telsa 14-50 plug adapter for the Gen2 Mobile Connector costs $45 from the Tesla store web site.
5) When using the Tesla Mobile Connector as your home charging solution you should not let the Mobile Connector chassis (the electronics brick) hang from the 14-50 receptacle. Tesla sells a Cable Organizer ($35) that includes a hanger for the charging cord an a wall mount bracket for the Mobile Connector chassis.

Total cost: $280 not including the wire or the labor, permits etc.

The Tesla Wall Connector costs $500, however you won't need any of the above items and would save some of the cost of the wire as you would only need to install 2 conductors instead of 3 (plus the ground wire.)

The Wall Connector can be configured for use on any of 60/50/40/30/20 amp circuits. The Wall Connector, with a corresponding 80% maximum charging amperage, when used on a 50A circuit will charge 25% faster than when using the NEMA 14-50 with the Mobile Connector. Faster still when used on a 60A circuit. The Wall Connector is fully weather rated (not really a benefit if you install the circuit inside a garage.)

For something less than $200 additional you can install the Wall Connector; it is worth considering.

 

[Rocky_H]

There is a lot to be said for that these days, because of some of those changes, like the GFCI breaker. For only about $200 extra, you also get an EXTRA charging device. Spending $275 on a second mobile charging cable makes no sense at all anymore.