Home Level 2 Charger Issues

Maquis

Well-Known Member
First Name
Dave
Joined
Dec 21, 2020
Threads
34
Messages
5,688
Reaction score
8,068
Location
Illinois
Vehicles
2021 Mach E4X, 2023 Lightning Lariat ER
Country flag
Are there any issues with plugging a device with it's own GFCI into a circuit with a GFCI breaker?
From an engineering perspective, no. All a GFCI does is compare the current flowing in the conductors. If all is well, it should net to zero (same number of electrons going out as coming back, in simple terms). If the out vs in varies my more than 0.006 amperes, it trips. (UL states it must trip between 0.004 and 0.006).

What can cause issues are surge protection schemes. Often surge protection circuitry connects from line to ground. If this circuit causes more than the 0.006 amps of leakage, the GFCI will trip. Devices that state not to connect to GFCI usually do so because of the type of internal surge protection they use.
Sponsored

 

Brademcee

Well-Known Member
First Name
Brad
Joined
Dec 29, 2020
Threads
5
Messages
231
Reaction score
324
Location
Chicago
Vehicles
Mach-E FE Blue Grabber, Tesla Model 3 Performance
Country flag
I am starting to wonder if switching out my 50-amp breaker will make a difference or possibly going to a hardwired EVSE (to eliminate the 240V outlet as a possible issue). I think there is some sensitivity to the charger in the MME with the 240V power and then the EVSE. Hopefully the dealer will let me take another MME home today to verify the issue repeats itself with another MME. I then know its not specific to my MME but something between the MME charger and the EVSE.
 

CHeil402

Well-Known Member
First Name
Chris
Joined
Sep 21, 2020
Threads
8
Messages
726
Reaction score
1,325
Location
King of Prussia, PA
Vehicles
2017 Audi A4, 2021 MME
Occupation
Electrical Engineer
Country flag
From an engineering perspective, no. All a GFCI does is compare the current flowing in the conductors. If all is well, it should net to zero (same number of electrons going out as coming back, in simple terms). If the out vs in varies my more than 0.006 amperes, it trips. (UL states it must trip between 0.004 and 0.006).

What can cause issues are surge protection schemes. Often surge protection circuitry connects from line to ground. If this circuit causes more than the 0.006 amps of leakage, the GFCI will trip. Devices that state not to connect to GFCI usually do so because of the type of internal surge protection they use.
From a Tesla forum, there was an issue with cascaded GFCI's because the Tesla Mobile Charger would 'verify' there was a solid ground by running some current to it during a self-test which would in turn trip the GFCI breaker. So no, in normal operation there is no issue, but if the end device performs any self-test like that (which I don't know if the Ford ones do) then it will cause an issue.
 

Maquis

Well-Known Member
First Name
Dave
Joined
Dec 21, 2020
Threads
34
Messages
5,688
Reaction score
8,068
Location
Illinois
Vehicles
2021 Mach E4X, 2023 Lightning Lariat ER
Country flag
From a Tesla forum, there was an issue with cascaded GFCI's because the Tesla Mobile Charger would 'verify' there was a solid ground by running some current to it during a self-test which would in turn trip the GFCI breaker. So no, in normal operation there is no issue, but if the end device performs any self-test like that (which I don't know if the Ford ones do) then it will cause an issue.
I don't doubt that to be true, but in my mind, that's poor design. The ground verification could be done at a current level low enough not to cause this issue.

I would also point out that the reason it trips the GFCI isn't due to cascaded GFCIs, per se, but rather to this unit self-test. Without this self test, the two GFCIs would have gotten along just fine.
 

dbsb3233

Well-Known Member
First Name
TimCO
Joined
Dec 30, 2019
Threads
56
Messages
10,100
Reaction score
11,965
Location
Colorado, USA
Vehicles
2021 Mustang Mach-E FE, 2025 Porche Macan Electric
Occupation
Retired
Country flag
Devices that state not to connect to GFCI usually do so because of the type of internal surge protection they use.
So from a practical standpoint, that sounds like a potential Yes.
 


dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
126
Messages
4,822
Reaction score
4,524
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
Wondering it if we can tell the MME it that its getting 50 amps.
you, or the electrician, can use a 'clamp ammeter' on the main conductors... Some of the better multi-meters ($50 and up) have this built in. This entails pulling the deadfront from the service panel and exposing you to 240vAC... so be careful.

you can also install a fancy 3rd party monitor like found at Sense.com or Efergy.com that will have clamp ammeters you can use to watch any circuit you want, including the main Utility service
 

bruceski88

Well-Known Member
First Name
Bruce
Joined
Aug 12, 2020
Threads
6
Messages
279
Reaction score
321
Location
CA
Vehicles
Mach e
Occupation
Retired Engineer
Country flag
I don't doubt that to be true, but in my mind, that's poor design. The ground verification could be done at a current level low enough not to cause this issue.

I would also point out that the reason it trips the GFCI isn't due to cascaded GFCIs, per se, but rather to this unit self-test. Without this self test, the two GFCIs would have gotten along just fine.
When I installed the Grizzle in Placer County, CA the inspector asked that I clamp the cable with the plug to the wall so it could not be easily removed from the outlet, so I think that was to make it dedicated. No such request in Sunnyvale CA.
 

malba2366

Well-Known Member
Joined
Dec 7, 2019
Threads
7
Messages
448
Reaction score
427
Location
NY
Vehicles
911 C2S
Country flag
Looks like I made it in under the wire last year. :)

Are there any issues with plugging a device with it's own GFCI into a circuit with a GFCI breaker?
From what I was told by my electrician you have a much higher chance of nuisance tripping with 2 GFCI. This is why he recommended not using a GFCI for the 14-50 plug he installed in my garage since the charge point charger has an internal GFCI.
 

Brademcee

Well-Known Member
First Name
Brad
Joined
Dec 29, 2020
Threads
5
Messages
231
Reaction score
324
Location
Chicago
Vehicles
Mach-E FE Blue Grabber, Tesla Model 3 Performance
Country flag
you, or the electrician, can use a 'clamp ammeter' on the main conductors... Some of the better multi-meters ($50 and up) have this built in. This entails pulling the deadfront from the service panel and exposing you to 240vAC... so be careful.

you can also install a fancy 3rd party monitor like found at Sense.com or Efergy.com that will have clamp ammeters you can use to watch any circuit you want, including the main Utility service
The electrician did this yesterday and confirmed we are getting the correct amps/volts from the panel and then also at the outlet.
 

JSW

Well-Known Member
First Name
Jeff
Joined
Dec 15, 2020
Threads
10
Messages
331
Reaction score
669
Location
Ann Arbor
Vehicles
Chevy Bolt; Porsche Boxster; Chevy Blazer; Jeep Wrangler
Country flag
Based on problems the OP and others are having, I decided to unpack my Ford mobile charger and try it. I’ve been using the same Clippercreek charging station in my garage for 4 years with other Evs, and most recently with the MMe. I plugged the Ford unit into the Clippercreek plug and, after a couple of faults/replugs, it’s charging as I write.

On an unrelated note, the mobile Ford unit is huge. I’m going to keep an old Chevy charger in the car and put the Ford unit in my back garage.
 

Maquis

Well-Known Member
First Name
Dave
Joined
Dec 21, 2020
Threads
34
Messages
5,688
Reaction score
8,068
Location
Illinois
Vehicles
2021 Mach E4X, 2023 Lightning Lariat ER
Country flag
When I installed the Grizzle in Placer County, CA the inspector asked that I clamp the cable with the plug to the wall so it could not be easily removed from the outlet, so I think that was to make it dedicated. No such request in Sunnyvale CA.
California has not yet adopted the 2020 NEC, so your installation is compliant - dedicated really has nothing to do with it.
 

Brademcee

Well-Known Member
First Name
Brad
Joined
Dec 29, 2020
Threads
5
Messages
231
Reaction score
324
Location
Chicago
Vehicles
Mach-E FE Blue Grabber, Tesla Model 3 Performance
Country flag
So I am proud to say that I am NOW able to charge the car from my 240V outlet using the Ford Mobile charger. I took the car to the dealer this morning for them to look at it but I do not think they performed any updates on the car. The sales person ended up driving to my house with another MME (35 miles each way) and another charger just in case. But when we got to the house, we connected the car again but this time after we inserted the charger into the charge port, he hit the unlock button. All of a sudden it started to charge normally. Not sure what the unlock button does on the charge port but after he did this, it is now charging from the 240V outlet. I have since taken the car out for another ride and now it is charging again but this time I did not have to hit the unlock button for it to charge. I have no idea what happened but now it seems to be charging fine.

Here is a pic (ignore my old Tesla sign in the background). I need to take that down and replace with something else like a Pony.

No idea why it is working now because unless the dealer did a software update (which I do not think they did nor did they tell me they did anything at the dealership), there is no reason why it should be working.

I will take what I can get! Now I just need to figure out why the tone settings for bass, treble and mid range are not saving after the car is powered off. That is a discussion for another forum.
Ford Mustang Mach-E Home Level 2 Charger Issues IMG_0705
 
OP
OP
jparduhn70

jparduhn70

Well-Known Member
Joined
Dec 27, 2019
Threads
16
Messages
517
Reaction score
702
Location
Knoxville, TN
Vehicles
2021 Mach-E First Edition
Country flag
So I am proud to say that I am NOW able to charge the car from my 240V outlet using the Ford Mobile charger. I took the car to the dealer this morning for them to look at it but I do not think they performed any updates on the car. The sales person ended up driving to my house with another MME (35 miles each way) and another charger just in case. But when we got to the house, we connected the car again but this time after we inserted the charger into the charge port, he hit the unlock button. All of a sudden it started to charge normally. Not sure what the unlock button does on the charge port but after he did this, it is now charging from the 240V outlet. I have since taken the car out for another ride and now it is charging again but this time I did not have to hit the unlock button for it to charge. I have no idea what happened but now it seems to be charging fine.

Here is a pic (ignore my old Tesla sign in the background). I need to take that down and replace with something else like a Pony.

No idea why it is working now because unless the dealer did a software update (which I do not think they did nor did they tell me they did anything at the dealership), there is no reason why it should be working.

I will take what I can get! Now I just need to figure out why the tone settings for bass, treble and mid range are not saving after the car is powered off. That is a discussion for another forum.
IMG_0705.jpeg
I’m happy it’s working for you. I haven’t had any luck yet. I swapped out the outlet today with a Bryant and it is a much more substantial one than the Leviton one that was originally installed. I tried pressing the unlock button and all that would happen with my car was a cycle on and off of the charger. I have a call in to my local Ford dealer and I asked them if they could bring a stock MME to my home to see if it will charge. Based on your experience, it’s almost like your charger learned something about the vehicle and then yours worked. Until the dealer has another in stock, I’m going to have to wait to see what’s going on.
 

malba2366

Well-Known Member
Joined
Dec 7, 2019
Threads
7
Messages
448
Reaction score
427
Location
NY
Vehicles
911 C2S
Country flag
So I am proud to say that I am NOW able to charge the car from my 240V outlet using the Ford Mobile charger. I took the car to the dealer this morning for them to look at it but I do not think they performed any updates on the car. The sales person ended up driving to my house with another MME (35 miles each way) and another charger just in case. But when we got to the house, we connected the car again but this time after we inserted the charger into the charge port, he hit the unlock button. All of a sudden it started to charge normally. Not sure what the unlock button does on the charge port but after he did this, it is now charging from the 240V outlet. I have since taken the car out for another ride and now it is charging again but this time I did not have to hit the unlock button for it to charge. I have no idea what happened but now it seems to be charging fine.

Here is a pic (ignore my old Tesla sign in the background). I need to take that down and replace with something else like a Pony.

No idea why it is working now because unless the dealer did a software update (which I do not think they did nor did they tell me they did anything at the dealership), there is no reason why it should be working.

I will take what I can get! Now I just need to figure out why the tone settings for bass, treble and mid range are not saving after the car is powered off. That is a discussion for another forum.
IMG_0705.jpeg
Glad you got it working! Does the Jukebox work now too?
Sponsored

 
 







Top