Nema 14-50 charging rate issue

[ilovemytdi]

Ok, so I have a rented model Y. I have a work garage with a 200 amp panel and really less than 20 amps pulling from it at any given time. I am using a mobile connector with a 14/50 dongle and when I plug it in the max charge rate I can get is 16/32 amps, approx 14 mph, regardless if the battery is at 10% to 80% SOC. I verified all connections are tight in the panel, breaker, plug, car, dongle. I tested each hot to verify its getting 120 volts separately and 240 volts combined.

I took the car and plugged it into another 14/50 plug at a different location and it goes straight to 32 amps and 29/30 mph charge rate.

I had an electrician friend come check connections and verify with his meter and he cant find anything wrong. I tried a different breaker and different nema 14/50. Its 6 gauge wire, 50 amp breaker, and total length of cable is 10 feet or less.

When charging at 16 amps the screen inside the car shows 231-232 volts steady.

Any suggestions? Any other info you guys need?

Thanks!!

 

[DSolie]

1) What size breaker is the 14-50 wired to?
2) Make sure the plug is inserted FULLY into the 14-50, and also, make sure it's inserted FULLY into the MY. Yellow flashing means only one leg is connected I believe.

 

[brkaus]

If you unplug, can you set the car to 32a (or higher)?

what is the voltage when you initially plug in? Does it drop as the current goes up?

 

[Rocky_H]

when I plug it in the max charge rate I can get is 16/32 amps

You don't really say, but have you tried to turn the current up or down on the charging screen in the car?

I took the car and plugged it into another 14/50 plug at a different location and it goes straight to 32 amps

This is why I was asking about changing the amps. If they had gotten changed while charging at a place, the car will memorize that amp setting at that location. So when you take it some other place, it would go ahead and try to use the full 32A again.

So possibly the amps were adjusted for some reason, and it's just using that memorized setting. But the other possibility is that part of the onboard charger has gone out. Internally, those are built of multiple modules that each handle 16A, and I've seen several cases on this forum where one of those modules died, and it loses 16A worth of charging capability. It's nice that it fails gracefully like that, though, instead of the whole thing just being dead because of part of it going out.

 

[ilovemytdi]

1) What size breaker is the 14-50 wired to?
2) Make sure the plug is inserted FULLY into the 14-50, and also, make sure it's inserted FULLY into the MY. Yellow flashing means only one leg is connected I believe.

50 amp breaker, everything is plugged in tightly, mobile connector flashes green from top to bottom

 

[ilovemytdi]

If you unplug, can you set the car to 32a (or higher)?

what is the voltage when you initially plug in? Does it drop as the current goes up?

I will check tonight, but like I said when I test at another location it ramps up to 32 amps within 30 seconds or so

 

[ilovemytdi]

You don't really say, but have you tried to turn the current up or down on the charging screen in the car?

This is why I was asking about changing the amps. If they had gotten changed while charging at a place, the car will memorize that amp setting at that location. So when you take it some other place, it would go ahead and try to use the full 32A again.

So possibly the amps were adjusted for some reason, and it's just using that memorized setting. But the other possibility is that part of the onboard charger has gone out. Internally, those are built of multiple modules that each handle 16A, and I've seen several cases on this forum where one of those modules died, and it loses 16A worth of charging capability. It's nice that it fails gracefully like that, though, instead of the whole thing just being dead because of part of it going out.

That's what I thought, but it works fine at the other location so I don't think it's a car issue.

 

[LevelHeaded]

Try manually increasing amperage on the car. As an earlier poster mentioned, it will use GPS to memorize amperage settings, so if for some reason it were set to 16 at this location maybe it’s remembering

 

[Rocky_H]

That's what I thought, but it works fine at the other location so I don't think it's a car issue.

Try manually increasing amperage on the car. As an earlier poster mentioned, it will use GPS to memorize amperage settings, so if for some reason it were set to 16 at this location maybe it’s remembering

Yes--that is why I had just explained that it would have a different current limit memorized at the other location.

 

[ilovemytdi]

Yes--that is why I had just explained that it would have a different current limit memorized at the other location.

First, thanks to all of those of you that have taken the time to reply! Great community here. So for some reason my garage location was set to 16 amp max. Changed it to 48 and the car automatically capped it at 32amps. Working like it should. Too bad it took me so long to ask for help.(im type A personality, I can do it on my own, who needs instructions, LOL)......turned the model Y back in this evening. (sad face) Anyway, when I rent it again or buy my own, I will know what to look for.

Prob gonna buy the Y in Jan, so only 5 more months!! Thanks again!

 

[tommywalker48]

If you unplug, can you set the car to 32a (or higher)?

what is the voltage when you initially plug in? Does it drop as the current goes up?

My model y drops from 32 amps down to 16 amps after approx 6 hour of charging; it never did this the first 10 months I owned the car. Electrician has checked breaker and plug and I swapped charging cord...still the overheat ( with the T in Tesla turning red after 6 hours) happens?!

Tommy Walker
Cell:512.965.5454

 

[tommywalker48]

My model y drops from 32 amps down to 16 amps after approx 6 hour of charging; it never did this the first 10 months I owned the car. Electrician has checked breaker and plug and I swapped charging cord...still the overheat ( with the T in Tesla turning red after 6 hours) happens?!

Tommy Walker
Cell:512.965.5454

The voltage stays the same. Always when I first plug in it's 32 amps at 230 volts.
How do I set the car to 32 amps? 32 amps always displays in the beginning of the charge

 

[jcanoe]

My model y drops from 32 amps down to 16 amps after approx 6 hour of charging; it never did this the first 10 months I owned the car. Electrician has checked breaker and plug and I swapped charging cord...still the overheat ( with the T in Tesla turning red after 6 hours) happens?!

Tommy Walker
Cell:512.965.5454

When you stated you swapped the charging cord, did you change the power plug adapter or replace the Tesla Gen2 Mobile Connector with another unit?

 

[tommywalker48]

The

When you stated you swapped the charging cord, did you change the power plug adapter or replace the Tesla Gen2 Mobile Connector with another unit?

Replaced the entire Tesla Gen 2 Mobile Connector with another unit from a factory new kit inside a Model 3 loaner I had at the time.
I assume the Tesla Gen 2 Mobile Connector to be the entire plug in cord assembly including the transformer which sequences green lights when properly charging..........my "T" in the Tesla logo turns red when the amps fall to 16. I immediately had the same result charging with the new cord. It's important to me that I have not had this issue for the first 10 months I have had the MY. Any suggestions you may have are appreciated! Tesla service doubts the entire issue and I have an appointment with them this Tuesday morning at 10:45. I am running down the battery prior to this Service appt as this phenomena has lately ALWAYS occurred after 5 to 7 hours continuous charging at my home. It does not occur on my NEMA14-50 home charging plug with charging 5 hours or less nor at Tesla Super Charging Stations.

TW

 

[tommywalker48]

Just plugged MY in again to double check.
32 amps at 236 volts.

 

[jcanoe]

OK; you have eliminated the circuit, receptacle as the source of the issue. You have also replaced the Tesla Gen2 Mobile Connector with another Mobile Connector.

Q1: When you switched the Mobile Connector did you also replace the NEMA 14-50 power plug adapter?

Q2: Do you let the Tesla Mobile Connector chassis (which by the way is not a transformer but a circuit board with relays) hang from the power plug adapter? If so, that puts unwanted strain on the receptacle and the power plug as neither is designed to support any additional weight, could be the cause of your charging issue now. (Tesla sells a Cable Organizer that includes a wall mount bracket for the Mobile Connector chassis, you can fashion your own support for the chassis or find similar mounting options on Amazon.)

As a next step I would change the NEMA 14-50 power plug adapter while supporting the Mobile Connector chassis so it does not hang from the power plug. If that does not solve the issue then the next link in the chain to investigate would be the Tesla Model Y's charging port.

 

[DOC-Y-NOT]

Hello, I just finished installed the NEMA 14-50 plug in my garage. I did follow the instructions from various sources here to have the 60amp breaker installed ..in case I chose to buy the tesla charger.....Still waiting on my YP which is slated EDD 12/7-21 ..but no VIN yet so who knows.

 

[jcanoe]

Hello, I just finished installed the NEMA 14-50 plug in my garage. I did follow the instructions from various sources here to have the 60amp breaker installed ..in case I chose to buy the tesla charger.....Still waiting on my YP which is slated EDD 12/7-21 ..but no VIN yet so who knows.

Well then you/you're electrician did it wrong. A 14-50 receptacle should never be installed on a circuit with a 60 amp breaker. The only acceptable circuit breaker is a 50 amp GFCI circuit breaker. (You can alternately install a 40 amp circuit breaker if there is not sufficient capacity for adding a 50 amp circuit.) Per the latest NEC, when used for charging an EV or other plug-in vehicle the circuit needs to be protected by a GFCI.

 

[DOC-Y-NOT]

Actually upon researching this with the electrician and based on others with Tesla's that currently have this setup. If the wiring can support 60 amps, then install a 60 amp breaker. Even if you connect a 50-amp outlet to the wiring (like a NEMA 14-50), then anything you plug into it has been designed to pull no more than 50 amps, so you won't overheat the wiring, outlet or the equipment.

 

[jcanoe]

Actually upon researching this with the electrician and based on others with Tesla's that currently have this setup. If the wiring can support 60 amps, then install a 60 amp breaker. Even if you connect a 50-amp outlet to the wiring (like a NEMA 14-50), then anything you plug into it has been designed to pull no more than 50 amps, so you won't overheat the wiring, outlet or the equipment.

You can pre-install wire that is rated for a 60 amp circuit but the circuit breaker should not exceed 50 amp unless you remove the 14-50 receptacle, hard wire the Tesla Wall Connector or other EVSE capable of supporting charging at 48 amp (11.5kW.) This is basic to electrical circuit wiring, safety.