Do NOT Plug a 48A Connector into a 50A outlet to charge your EV.

[BennyTheBeaver]

I plan on plugging a 48a EVSE into a NEMA 14-50 plug.

You can do this, just need to be sure the model you purchase has adjustable amperage and it needs to be dropped to 40a (which I will be doing).

My reasoning: I have a NEMA 14-50 ready to go, but want the extra amperage should I choose to call an electrician and get the system hardwired in the future.

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[Shady]

I am installing a 48amp hardwired charger. Well its adjustable up to 50 amps. I have a SR Pro so will set it at 48amps.

I ran 4 stands of #4 copper stranded wire in case I need to use it for a future endeavor it was easy to do now lol. On a 60 amp breaker Aprox a 30ft run.

The charger has L1 L2 and PE. I am no electrician but I know its a 240 circuit and L1 and L2 are the line wires to get it to 240. Would PE go to Ground Or Neutral or I am an idiot for doing this myself and I should let an Electrician do it so I don't burn my garage to the ground.


I have already ran the wires and installed the breaker and connected the wires to the breaker ran the wires and conduit to the charger tested for 240 and called it a day. I just want to make sure I was correct about the wires before connecting them. again a the charger I have L1 L2 Ground and Neutral wires just want to be sure what I should connect to the PE terminal

 

[jimfigler]

I am installing a 48amp hardwired charger. Well its adjustable up to 50 amps. I have a SR Pro so will set it at 48amps.

I ran 4 stands of #4 copper stranded wire in case I need to use it for a future endeavor it was easy to do now lol. On a 60 amp breaker Aprox a 30ft run.

The charger has L1 L2 and PE. I am no electrician but I know its a 240 circuit and L1 and L2 are the line wires to get it to 240. Would PE go to Ground Or Neutral or I am an idiot for doing this myself and I should let an Electrician do it so I don't burn my garage to the ground.


I have already ran the wires and installed the breaker and connected the wires to the breaker ran the wires and conduit to the charger tested for 240 and called it a day. I just want to make sure I was correct about the wires before connecting them. again a the charger I have L1 L2 Ground and Neutral wires just want to be sure what I should connect to the PE terminal

Pe is ground (protective earth) not all hardwire units use a neutral

 

[Maxx]

Off topic but mildly related newbie question: I have a portable charger that I can adjust to almost anything bellow 40 Amp. It is 25’ long but the 30 amp dryer plug is almost 40 feet away. I may have to do this 10-20 times a year. This is a vacation property that I am not sure how long we will keep. It has 80 amp service with a 200 amp panel with lots of unused spots. Can I add a 25’ extension cord to my charger without setting anything on fire? What is the maximum safe current for this setup? 25% brings me down to 22.5 AMP. I have 20 and 24 so I am guessing 20 should be OK? Or this whole setup is asking for trouble and I have to do something dedicated?

 

[Maquis]

Off topic but mildly related newbie question: I have a portable charger that I can adjust to almost anything bellow 40 Amp. It is 25’ long but the 30 amp dryer plug is almost 40 feet away. I may have to do this 10-20 times a year. This is a vacation property that I am not sure how long we will keep. It has 80 amp service with a 200 amp panel with lots of unused spots. Can I add a 25’ extension cord to my charger without setting anything on fire? What is the maximum safe current for this setup? 25% brings me down to 22.5 AMP. I have 20 and 24 so I am guessing 20 should be OK? Or this whole setup is asking for trouble and I have to do something dedicated?

The derating factor is 20%, not 25. So you are allowed 24A continuous on a 30A circuit.
You didn’t say how far the panel is from the parking area, but I’d look at running a new circuit for charging.
If you must use an extension cord, getting one with J1772 ends to use on the output of the EVSE is probably best as well as most versatile.

 

[Maxx]

The derating factor is 20%, not 25. So you are allowed 24A continuous on a 30A circuit.
You didn’t say how far the panel is from the parking area, but I’d look at running a new circuit for charging.
If you must use an extension cord, getting one with J1772 ends to use on the output of the EVSE is probably best as well as most versatile.

Thanks for taking the time to respond. Panel direct distance to the parking area is 15’ but the cable run may be as long as 25’. I didn’t know about J1772 extension cords. Great tip.

I am trying to understand the main problem with using extension cord. Is it additional contact/failure points that is the concern? Or additional resistance that may cause voltage drop, heat loss, inefficiency or stress on the charger? And if more charging time is available, will reducing current, reduce those concerns?

Another question, if I do wire a dedicated reciprocal, is it OK to put in 30 amp breaker, wiring for 30 amp but 14-50 reciprocal so I won’t have to use another adapter with my charger? And I hear if the breaker is GFCI, there may be conflict with GFCI protected charger. This is near water property and everything outside is GFCI protected. If I go that rout, I wouldn’t want to wake up with empty battery. What would you suggest for breaker?

 

[Shady]

Thanks for taking the time to respond. Panel direct distance to the parking area is 15’ but the cable run may be as long as 25’. I didn’t know about J1772 extension cords. Great tip.

I am trying to understand the main problem with using extension cord. Is it additional contact/failure points that is the concern? Or additional resistance that may cause voltage drop, heat loss, inefficiency or stress on the charger? And if more charging time is available, will reducing current, reduce those concerns?

Another question, if I do wire a dedicated reciprocal, is it OK to put in 30 amp breaker, wiring for 30 amp but 14-50 reciprocal so I won’t have to use another adapter with my charger? And I hear if the breaker is GFCI, there may be conflict with GFCI protected charger. This is near water property and everything outside is GFCI protected. If I go that rout, I wouldn’t want to wake up with empty battery. What would you suggest for breaker?

the Breaker should be aprox 10% higher than the amps drawn.

The longer the run from panel to charger you tend to loose some amps I think but I dont think that is a factor till you hit around 100 feet to be noticeable

The 14-50 box just needs to be for a MINIMUM 30 amps for your 30 amp service.

If you are running a new circuit the cost to run more amps at the time of install is cheap compared to redoing it if you want more. and the charge time from a 30 amp to a 48 amp is significant. I guess that depends if you already have the charger .


I am not an electrician.

 

[Shady]

Finished my 48 amp charger install and no genie escaped the charger so the magic is happening.

It was a struggle to plug in the Truck the first time I sure did not want the magic smoke to escape

Thanks for the info and making me feel better about it being right.

On 110 I got 3 miles per hour charge. With the 48 its looking like close to 30 miles an hour added.

 

[Maquis]

Thanks for taking the time to respond. Panel direct distance to the parking area is 15’ but the cable run may be as long as 25’. I didn’t know about J1772 extension cords. Great tip.

I am trying to understand the main problem with using extension cord. Is it additional contact/failure points that is the concern? Or additional resistance that may cause voltage drop, heat loss, inefficiency or stress on the charger? And if more charging time is available, will reducing current, reduce those concerns?

Another question, if I do wire a dedicated reciprocal, is it OK to put in 30 amp breaker, wiring for 30 amp but 14-50 reciprocal so I won’t have to use another adapter with my charger? And I hear if the breaker is GFCI, there may be conflict with GFCI protected charger. This is near water property and everything outside is GFCI protected. If I go that rout, I wouldn’t want to wake up with empty battery. What would you suggest for breaker?

Most extension cords are mass-produced for lowest cost. The plugs and sockets tend to heat up under continuous load. Might only be inefficient, but could be dangerous. Yes, less load can mitigate the issues.

All outside receptacles must be GFCI-protected per the NEC. The idea that a circuit with multiple GFCIs causes nuisance tripping is urban legend. Think about every blow dryer with a GFCI built into the plug being used in a GFCI bathroom receptacle without issue.

For a 15’ run, I’d go ahead and run a 50A circuit. It’s not going to increase the cost that much. That will allow you to use the supplied Ford Mobile Charger, if needed.

 

[Maquis]

the Breaker should be aprox 10% higher than the amps drawn.

The longer the run from panel to charger you tend to loose some amps I think but I dont think that is a factor till you hit around 100 feet to be noticeable

The 14-50 box just needs to be for a MINIMUM 30 amps for your 30 amp service.

If you are running a new circuit the cost to run more amps at the time of install is cheap compared to redoing it if you want more. and the charge time from a 30 amp to a 48 amp is significant. I guess that depends if you already have the charger .


I am not an electrician.

For continuous loads such as EVSEs, the circuit must be used at not more than 80% of its rating. If you do the inverse math, the breaker ends up being 25% higher than the EVSE, not 10. Example: 30A circuit for a 24A EVSE.

Long runs result in voltage drop, not amps. The power delivered for charging is reduced either way.

 

[GoGoGadgetTruck]

The NEC limits plug in EVSEs to a max 50A circuit which means a 40A EVSE. So anything larger MUST be hard-wired to be legal.

I've seen this stated repeatedly, but I have never seen a specific reference. Given that 14-60 exists, I did a little searching and found

Does electrical code allow NEMA 14-60R receptacles in residential settings? - Home Improvement Stack Exchange

Is there EVSE-specific info elsewhere in the NEC? Because between that and the definition of "individual branch circuit" I see at

National Electrical Code Basics: Branch Circuits Part 1 - Technical Articles (eepower.com)

It looks like a NEMA 14-60 with a dedicated circuit should be fine for 48A use?

 

[Maquis]

I've seen this stated repeatedly, but I have never seen a specific reference. Given that 14-60 exists, I did a little searching and found

Does electrical code allow NEMA 14-60R receptacles in residential settings? - Home Improvement Stack Exchange

Is there EVSE-specific info elsewhere in the NEC? Because between that and the definition of "individual branch circuit" I see at

National Electrical Code Basics: Branch Circuits Part 1 - Technical Articles (eepower.com)

It looks like a NEMA 14-60 with a dedicated circuit should be fine for 48A use?

625.44 describes the acceptable receptacle outlets for EVSEs. The largest mentioned is 50A.
And follows with “all other equipment shall be permanently wired…”

 

[GoGoGadgetTruck]

625.44 describes the acceptable receptacle outlets for EVSEs. The largest mentioned is 50A.
And follows with “all other equipment shall be permanently wired…”

Thank you for the specific reference. It's very helpful.

 

[Shady]

625.44 describes the acceptable receptacle outlets for EVSEs. The largest mentioned is 50A.
And follows with “all other equipment shall be permanently wired…”

I wonder how long ago that standard was written and if changes are due to it now that 50+ amp chargers are getting fairly common.

 

[Kev12345]

are you saying the ford mobile connector doesn't derate automatically based on the plug end? Tesla does this with the dongles. 50 amp dongle will only draw a max of 40 amps. 30 amp dongle will only draw 24 amps etc.

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