# Which outlet to use?



## halestorm (Apr 28, 2009)

Sorry, this is a tough thing to search for as it matches many unrelated items.

I want to install a dedicated 30A 220v circuit in my garage for charging. My charger is a PFC2500 168-12. This charger is programmed for 1350W output on 110v and 2420W output on 220v. So on 110v the AC input current is 1350W / 0.9 = 1500W AC / 110VAC = 13.6A and on 220v the AC input current is 2420W / 0.9 = 2689W AC / 220VAC = 12.2A.

I already have an existing 220v 30A circuit breaker with 10ga wire, but wired to nothing at this point, just an empty box with wire nuts on the end.

My confusion is that when I go to the hardware store looking at 30A/220v outlets, there are different types, a couple of different flat blade types and some twist locks. Which do I select, and why?


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## Sunking (Aug 10, 2009)

There are only two choices, and the answer lies in how many wires are required for your charger. It is either 3-wire or 4-wire.

3-Wire is a NEMA 6-30P. It provides L1, L2, and G. Strictly a 250 volt 30 Amp plug with *NO* Neutral.

4-Wire is a NEMA 14-30P. It provides L1, L2, N, and G. It is 250/125 volt 30 Amp plug.. With the *neutral* gives you 125 VAC . Examples are dryers and ovens where the heating elements operate at 250 VAC, and the motors and controls work from 125 volt.

So look and see what your charger requires. NEMA Plug/Receptacle designations are 1, 2, 5, 6, 7, 10, 14, 15, and 18. Following the Designation is the Current rating, followed by Plug or Receptacle For a home today in the USA with Single Phase Service 250/125, there are only three code compliant plugs/receptacles you can use. Those are 5, 6 and 14. Designations 1, 2, and 10 are no longer acceptable because they DO NOT have a Ground Conductor, and for reference only for older homes. 

FWIW there is no such thing as 220 and 110 volts in the USA. That standard died decades ago. It is 250/125.


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## halestorm (Apr 28, 2009)

Sunking said:


> There are only two choices, and the answer lies in how many wires are required for your charger. It is either 3-wire or 4-wire.


and apparently twist-lock or not? I don't see any twist-locks in your chart, yet that appears to be an option as well.




Sunking said:


> So look and see what your charger requires.


The charger was just supplied with a 10ga power cord. I can put any connector onto the end that I want. I've been using it on a 110v/15a circuit (sorry, "125v") so I have a standard household plug on it now. It is two hots and a ground. The company says I can use whatever plug/outlet I want.


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## Sunking (Aug 10, 2009)

halestorm said:


> and apparently twist-lock or not? I don't see any twist-locks in your chart, yet that appears to be an option as well.


That would be NEMA LX-YYP series. In that series there is only one option of L6-30P 250 volt 30 amp. Only a 3-Wire L1, L2, and G. There is no 4-wire option for 250/125. I would advise against using Locking. 






halestorm said:


> The charger was just supplied with a 10ga power cord. I can put any connector onto the end that I want.


No not by code you cannot. If you were to use say a NEMA 5-15P like every 125 volt house receptacle you have two problems. 

1. It is only rated for 125 volts @ 15 amps, and you are using 250 volts @ 30 amps. Recipe for a FIRE and Stupidity

2. It is a standard 120 volt receptacle that any fool can plug in a 120 volt cord and unknowingly some idiot wired it for 250 volts. Another excellent recipe for fire and stupidity. 

That is why we have codes and standards so you cannot plug in an inappropriate connector. When you see a receptacle you know immediately what it is. 

*So how many wires are in the Power Cord, Voltage and Current is all you need to know?*

*We know 250 volts at 30 amps.*

If it is 3-wires, you have two options. You can use a 6-30P or L6-30P if you want locking.
If it is 4-wires, you use a 14-30P.

It will take a minimum 10AWG copper from your breaker box to receptacle. 

Not rocket science, just Black and White. Pick one.


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## miscrms (Sep 25, 2013)

You should be able to use either 6-30 or 14-30 then. Putting a 6-50 or 14-50 plug on the charger would also be ok, but you do not want to put a 6-50 or 14-50 receptacle on a 30A circuit.

One thing to think about to help choose might be other places where you might want to plug in. 

My understanding is that 6-30 are more common in shops for welders, 240V saws, etc. If you have friends with shops where you might want to plug in that might be a good choice. They could also be 6-50, which you'd need an adapter for down to 6-30.

14-30 is common for clothes dryers. There are probably a lot more of these around than 6-30 in general. Older dryers outlets may be ungrounded 10-30 though.

14-50 are what you are likely to find in an RV park, so you'd need an adapter down to 14-30. 

Twist lock are not common to my knowledge. If a cord gets pulled, you generally want it to come out of the socket rather than rip it off the wall or break something exposing the wires. I think boats might use twist lock to avoid water splashing on a loose plug connection?

I would put in 14-30 unless you have other equipment (welder etc) with a 6-30 that you'd like to plug in, or know you will be visiting someone with a 6-30 outlet with some regularity.

Rob


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## Sunking (Aug 10, 2009)

miscrms said:


> Putting a 6-50 or 14-50 plug on the charger would also be ok,


 No it is not. His Power Cord is 10 AWG, and 30 amps is max on 10AWG. The other issue is the device is designed for 30 amps. If there was a fault inside the charger connected to a 50 amp circuit, fault current would higher than the charger can withstand. 

If an insurance adjuster or FD were to catch it as part of a claim would be denied, and the Home Owner would be held responsible and liable for all damages and injuries.


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## halestorm (Apr 28, 2009)

Sunking said:


> No not by code you cannot. If you were to use say a NEMA 5-15P like every 125 volt house receptacle you have two problems.


ok, sorry I wasn't entirely clear. Certainly not "anything I want" but there is some freedom. As mentioned in the original post, the charger can be either 120v or 240v. I can outfit it with a 120v/15A plug as I have now, or a 240v plug.


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## halestorm (Apr 28, 2009)

Sunking said:


> No it is not. His Power Cord is 10 AWG, and 30 amps is max on 10AWG. The other issue is the device is designed for 30 amps.


Actually, as stated in the original post, the device is less than 15A.

I think my un-used 30A breaker is going to be over kill and I would be better served to replace it with a 20A breaker.

I don't like the 15A/120v circuit it's on now; as stated, the extension cord from the car to the wall gets too warm for my comfort. Even though the cord and all of the wire is the correct gauge and I'm not tripping any breakers, the charger is on for a long period of time, not cycling on and off like my refrigerator or air conditioner. If I run it at 240v I'll drop the current down to only 12.2A instead of 13.6A. So I guess really a 6-15 ought to be sufficient, but 6-20 seems a little more comfortable, for the same reason why 5-15 isn't satisfactory.


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## Sunking (Aug 10, 2009)

halestorm said:


> If I run it at 240v I'll drop the current down to only 12.2A instead of 13.6A. So I guess really a 6-15 ought to be sufficient, but 6-20 seems a little more comfortable, for the same reason why 5-15 isn't satisfactory.


Strange, as I would think it is either 240 or 120, not both. Anyway 250 volts @ 12.2 amps is 3000 watts, and 125 @ 13.6 is 1700 watts. So 250 is going to be a lot faster.


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## Moltenmetal (Mar 20, 2014)

Sunking is not entirely correct, though his advice is motivated by a desire to keep you safe.

You are correct that source breakers have to be sized to protect conductors in the wall, and to protect the conductors in receptacles connected to the circuit. The weakest link sets the maximum permitted breaker rating.

Any device may have a feeder cord of gauge lighter than the full rating of the plug attached to it- but ONLY if the device itself protects its cord's conductors with a fuse or circuit breaker internal to the device itself. Example- a clock radio, any stereo component etc. 18 ga cord, tops, but internally fused to protect the light gauge cord. You would think this is unsafe because a short circuit through the cord, ie because someone sticks a pin through both conductors- would lead to currents higher than the cord is rated for and yet this is done all the time in approved devices.

A call to ElCon, or a pm to Wolftronix who repairs these chargers, would tell you if they are internally protected against line currents in excess of the rating of their 10 ga cord- I'm fairly certain they are, but check to be sure. if so, you could legitimately put a 30' 40 or even 50 A plug on that cord, because you are no longer relying on the circuit breaker in your panel to protect the cord's conductors- only the conductors in your wall. Sticking with a plug rated no higher than 30 A is still safest though.

I'd use a dryer or range receptacle or welder socket from a big box store. I may misremember, but one is 30A and the other is 40, one has the neutral you don't need and the other doesn't- I don't remember which is which. These will be fine for you, and will be the cheapest option by far. The other, less frequently used plugs/sockets can tend to cost 3-5x as much, depending on where you source them. 

Install conductors and a breaker which match the rating of the wall socket you select.

Once you confirm that the ElCon is indeed fused internally at no more than 30 A to match its 10 ga cord, buy a matching plug for your socket, slice off the existing 15 A 120V plug and replace. You'll likely need an extension cord though, too, and it will need to use the same 10 ga wire or heavier that the ElCon uses. Then, I suggest you also make up a reverse cheater cord- one that allows you to supply your dual voltage charger from a 120 V regular outlet, despite having a 240 V plug installed on it permanently. There is no safety problem doing so, unlike the reverse situation, ie a 120 V plug being fed 240 V from an improperly wired 120 V outlet which is not rated for the higher voltage...that's a recipe for fire as Sunking says- somebody will plug the wrong thing into that socket some day, guaranteed. 

Keep this reverse cheater cord and a 12 ga 120 V extension cord, in your trunk in case you get stranded somewhere and 120V is all that's at hand. Cheap insurance, which I've personally had to use on the road quite unexpectedly!

I also recommend terminating charge on the ElCon by using a switch installed on the BMS interlock, if you must prematurely stop charging. Do not unplug the charger under load, irrespective of the ampacity of the plug- at least not on purpose!

There are many more complex options that are also adequately safe.

The safest alternative is to install a J1772 port and to buy an EVSE to supply it. Neither are cheap, but they do offer idiot resistance and safety.


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## miscrms (Sep 25, 2013)

Beat me to it MM, I think you're right on the money. I would assume the charger is fuse protected on the AC side, but its good to make sure. If so, there should be no significant issue putting a higher rated power plug/cord on it, or driving it from a circuit with excess current rating.

NEMA 6-30R is a common 30A welder socket, with two hots and ground. NEMA 14-30R is the common 30A dryer socket, with two hots, neutral and ground. If the charger doesn't require neutral, which it seems not to, you can use either. If the wiring in the wall has all 4 conductors, it might make sense to just use the 14-30, but its really fine either way.

Rob


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## Sunking (Aug 10, 2009)

Moltenmetal said:


> Sunking is not entirely correct, though his advice is motivated by a desire to keep you safe.
> 
> You are correct that source breakers have to be sized to protect conductors in the wall, and to protect the conductors in receptacles connected to the circuit. The weakest link sets the maximum permitted breaker rating.
> 
> Any device may have a feeder cord of gauge lighter than the full rating of the plug attached to it- but ONLY if the device itself protects its cord's conductors with a fuse or circuit breaker internal to the device itself.


That is not entirely correct, but I understand the point you are trying to make. 

In order for a OCPD (over current protection device) to work and protect the conductors has to be up stream. No fuse or breaker in the device can protect the plug cord, only what is inside down stream.

To your point and credit I am speaking with respect to NEC which mandates teh rules for the facility wiring to the receptacles. After that point falls upon UL or other credited listing agency. No company or listing agency would instruct an owner or install inappropriate plugs or undersized wiring. Example a NEMA 5-15P or 5-20P on a device that uses 250 volts at 30 amps. No such design would be listed or approved. If they did is a bankrupting law suite waiting to happen. 

You are right safety is my priority as it comes from being a licensed PE of 35 years. Stop and think about this. If you go buy a extension with 3-wire and a 6-15P on it, it will have a minimum 14 AWG wires. If it has 3 wires and a 5-20P on it the conductors will be 12 AWG. Both correlate to NEC minimum wire requirements for 15 and 20 amp OCPD's. 

The key here the power cord supplied with the Charger. How many conductors and what size and color are they? If they are 14 or 12 AWG with a Black, White, and Green conductors, the device is intended to be a NEMA 5-15, 5-20 circuit respectively. If there are 3 10 AWG conductors with two Black, and one green, it is intended to be a 6-30 circuit, or one could use a 14-30 plug as there would just not be a Neutral conductor terminated on the Plug cord and that would allow it to be used on a NEMA 14-30 receptacle. 

Not only is there a safety issue at hand, but also performance. Undersized wire and plugs not only get warm, they loose a lot of power. That is what the heat is from. 

The debate is really a moot point IMO. If the charger is from a reputable manufacture like Elcon, the circuit requirements are in the owners manual. My educated guess is the Charger in question is made for International distribution, and they did not terminate it with a plug as each country has its own standards for plugs and receptacles. 

All I can do is advise the OP to comply with standards. Using a nonstandard plug configuration is just dangerous. Example wiring a NEMA 5-15 or 5-20 plug on a 250 volt 30 amp circuit. The next guy that plugs something into it is in for a nasty shock when he is expecting a 120 volt circuit. So based on latest information the OP says the circuit is 250 volts @ 15 amps. If that is true needs to be a NEMA 6-20 for 3-wire, or NEMA 14-20 for 4 wires. 

Look in the manual. That is what a licensed electrician would do, and has to do if he wants to keep his license and insurance. A Inspector would not accept anything else. 

Keep it Sane and Safe.


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## ken will (Dec 19, 2009)

As far as over-sized plugs go;
There is legal-technical correctness....
And then there is Reality!

NEMA matches *clean *plug power rating to wire ratings. 

In reality the connectors get dirty, increase in resistance, and get hot!!

If you use Nema rated over-sized plugs, then they will better match the wire ratings after they get used a few times.


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## Moltenmetal (Mar 20, 2014)

> To your point and credit I am speaking with respect to NEC which mandates teh rules for the facility wiring to the receptacles. After that point falls upon UL or other credited listing agency.


 Correct. And what the OP is planning to do is to modify a device ("appliance") in the scope of UL/FM/ETL etc. by adding a plug which has an ampacity greater than the maximum current demand of the device. I visited the ElCon website as well as looking at the datasheet for my own PFC2500 and found no mention of their charger being approved by UL- I sincerely doubt that it is UL approved/listed, and I doubt it's ETL, FM or even CSA approved/listed. 

Does a listed charger for DIY auto applications actually exist? I doubt the devices inside OEM vehicles are UL listed either- their safety rules are covered by DOT or other standards, and compensation of the victims is covered by product liability.

Strictly speaking, if you modify a UL approved/listed device in any way it is no longer UL approved. That probably goes for replacing the molded plug end on your electric lawnmower or the socket or plug end on your extension cord by the way, if you want to be ridiculous!

Them's the rules: then there's what makes sense. 

Conductors in the wall running between the breaker and the socket must be protected at the inlet end by the breaker. That's consistent with the rules, good practice and commonsense. Doing anything else is courting disaster.

But cords on approved end-user devices are nearly always sized for far less than the current required to trip the supply breaker. That's the rule rather than the exception. In those cases, the cord's conductors are in fact protected by a current limiting device in the end-user appliance itself. That device protects the conductors from short circuits or other high current faults occurring inside the device itself. It does not protect the cord from excess currents which may be drawn in the case of damage to the cord itself. 

Furthermore, you can buy UL approved extension cords which are fitted with plugs and sockets rated for 15 A, despite having conductors of only 18 ga.!

How on earth could that ever be considered safe? It isn't safe- there is a certainty that there have been fires as a result of overloaded extension cords or damaged supply cords. I'm not a lawyer, but I'm unaware of any case where a fire insurance claim was denied because someone used an extension cord of too light a gauge. 

In my opinion, this isn't a tragedy- quite the opposite. It's the triumph of commonsense over the stupid and blind application of rules. The reason you are permitted to sell appliances and extension cords with cords lighter than the rating of the plugs they have on them is simple: the risk of fire exists, but in practice is very small. This small risk is balanced against the benefit of not requiring 14 ga minimum conductors on every single consumer electronics item irrespective of what current it could pull.

Take as another example the "bisexual" 15/20A u ground outlet which you can buy at any big box store. That outlet can be supplied with 12ga conductors and connected to a 20A breaker- and yet every device you plug into it with a 15A plug on it, will no longer be protected by the upstream breaker. Does plugging a UL approved device into that UL-approved bisexual outlet violate the downstream device's UL certification? It probably does- the UL approval/listing process probably requires some peak current handling capability of the cord before it burns, which is determined by the cord's installed length, limited to 15A by the upstream breaker- and the result would likely change if it were fed from a 20A breaker... 

My advice to the OP stands: I suggest you cut the plug off your (likely) non-listed charger and replace it with a 30A 240V plug. It's the most practical solution, and though even using the charger is likely a violation of the letter of the codes and standards, modifying the charger in this way is unlikely to increase that risk in any meaningful way. 

Let's be realistic: this is likely the most minor of the electrical sins a DIY electric car converter will commit in the course of their project!  

A word of warning: be very careful plugging in and unplugging those large plugs, especially the ones which are offset so the cord comes out parallel to the surface of the receptacle rather than perpendicular to it. It's very easy to get your thumb on one conductor and a finger on the other, or on ground...and again, never disconnect these ElCons while under load- even if you end up supplying the unit via an EVSE. Look at the repair thread- to me, there's enough evidence of the ElCon units blowing up as a result of this happening one time too many. Arrest charge using the BMS interlock which is the way the unit is designed to have charging arrested. That's the safest way anyway, even if the ElCon can handle it which I doubt.


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## Sunking (Aug 10, 2009)

Moltenmetal said:


> Furthermore, you can buy UL approved extension cords which are fitted with plugs and sockets rated for 15 A, despite having conductors of only 18 ga.!


No you cannot. It would be 14 AWG minimum. Building power and lighting wiring are covered by NEC. Using 12 AWG as an example per NEC can carry as little as 10 amps in a conduit with 75 degree insulation bundled with 10 or more conductors. If the cable insulation is rated for 90 degrees in Free Air is 40 amps. Even in NEC 18 AWG can go as high as 14 amps. 

Power cords do not fall under NEC jurisdiction. They fall under UL. But like NEC the current rating depends on a large degree the temperature rating of the conductor insulation, whether or not it has free air circulating, bundled, ect. In apparatus up to 25 amps. However in the case of UL is much more limited and is determined by number of conductors, length, and size. 18 AWG with 2 current carrying conductors less than 50 feet is 10 amps. *Look it up here.* For UL approved NEMA Power cords* look here*



Moltenmetal said:


> My advice to the OP stands: I suggest you cut the plug off your (likely) non-listed charger and replace it with a 30A 240V plug.


I agree and is what I have been saying all along.


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## evmetro (Apr 9, 2012)

I absolutely love using the 6 50. I have one of these inlets in the fuel filler neck of each one of my conversions, and it is a rugged inlet. I squish the male plug end into a metal junction box with a metal lid on it so I can ram my extension cord onto it and off of it with out worrying about anything. It is also the standard connection for 220V welders, so I can plug in with my welder extension cord when I pull into my shop. I wire the plug end from my fuel filler door to my charger with 3/6, but I have to get the strands out of the fat extension cord material that it comes in when I buy 3/6 at home depot. The casing is probably there for a reason, but the 6 gauge wire that I pull out is REALLY flexible and easy to route. I don't know the ins and outs of wiring code, but I can say that the 6 50 is a very rugged connection that is worth using on an EV. If you need to upgrade the wiring in the car to be appropriate for a 6 50, it may be worth it if you want a rugged connection.


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## Moltenmetal (Mar 20, 2014)

> Quote:
> Originally Posted by *Moltenmetal*
> _Furthermore, you can buy UL approved extension cords which are fitted with plugs and sockets rated for 15 A, despite having conductors of only 18 ga.!_
> 
> No you cannot. It would be 14 AWG minimum. Building power and lighting wiring are covered by NEC. Using 12 AWG as an example per NEC can carry as little as 10 amps in a conduit with 75 degree insulation bundled with 10 or more conductors. If the cable insulation is rated for 90 degrees in Free Air is 40 amps. Even in NEC 18 AWG can go as high as 14 amps.


 To clarify what I was saying, yes indeed you CAN buy an 18 ga extension cord with NEMA 15A rated plugs and sockets on it, so there must not be a rule in UL that requires a cord's conductors to meet or exceed the ampacity of the plug you put on it. These cords are UL or CSA approved, and yet their conductors are not rated for the current that may be pulled through the cord if the only circuit protection is the breaker in the panel supplying the circuit. 

Obviously you won't be running an extension cord in conduit and shouldn't be bundling it with other conductors so the heat dissipation de-rating doesn't come into it- until someone runs it under a rug etc.! It's a far cry from a truly "safe" design practice. Rather, the practice of putting a 15 A plug on an 18 ga cord is marginally unsafe to some uses, but can be and typically is safe for its intended use, and is also very practical. Fortunately commonsense still prevails- at least to some degree.


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