Can I set up a Wall Connector and Nema 14-50 using the same line?

[joebruin77]

So my Wall Connector is temporarily down while the handle or plug is being repaired. I am going to have my electrician install a Nema 14-50 outlet next to the hard-wired Wall Connector. So in the future, if the Wall Connector is inoperable for any reason, I have the Nema 14-50 as a backup.

My question is this. I do not plan on using the Wall Connector and the Nema 14-50 outlet at the same time. I would only use the outlet if the Wall Connector is down. Is there some sort of device my electrician can set up so that the Wall Connector and the 14-50 outlet use the same electrical line from the breaker box, kind of like a Y switch? I would want a set up that is safe and is in accordance with building codes.

I welcome any thoughts or suggestions.

Thank you,
joebruin77

 

[DCGOO]

The short answer is of course you can. 50 amp breaker maximum on the line, 6 gauge wire. The only consideration I can think of is if you install a 14-50, you will need to include the neutral (3rd wire). The WC does not require the neutral. (both require a ground). Unlike installing multiple Wall Connectors on the same line, there is no load sharing configuration, limiting the total current. So if you mess up and use both (mistake), you will pop the breaker. But that is what the breaker is for.

 

[joebruin77]

Good news, I received a reply from the Tesla online store today, from someone in "Tesla Charging Installation". They asked me to send them pictures of my damaged plug and said they will check to see if it might be covered under the warranty. Yay Tesla!

 

[DCGOO]

Good news, I received a reply from the Tesla online store today, from someone in "Tesla Charging Installation". They asked me to send them pictures of my damaged plug and said they will check to see if it might be covered under the warranty. Yay Tesla!

Referring back to my original reply, you can only install the 14-50 if the line has the neutral available. The 14-50 requires it, the Wall Connector does not.

 

[brkaus]

And if your wall connector is on a 60a breaker, cannot connect a 14-50 to it.

 

[joebruin77]

And if your wall connector is on a 60a breaker, cannot connect a 14-50 to it.

Yes, the Wall Connector is on a 60amp breaker. So if I want a 14-50 next to the Wall Connector, the electrician would have to run a new and separate line from the breaker box? What amp size should the breaker be for the 14-50 outlet?

 

[miimura]

The best way to connect two non-concurrent loads to one circuit is a double throw safety switch. Notice the one linked below has a lever action that is ON / OFF / ON. That way only one device can be powered or a device can only be powered by one source.

GE 60 Amp 240-Volt Non-Fused Indoor General-Duty Double-Throw Safety Switch-TC35322 - The Home Depot

Of course, this does not resolve the 50A vs. 60A issue.

 

[Rocky_H]

My question is this. I do not plan on using the Wall Connector and the Nema 14-50 outlet at the same time. I would only use the outlet if the Wall Connector is down. Is there some sort of device my electrician can set up so that the Wall Connector and the 14-50 outlet use the same electrical line from the breaker box, kind of like a Y switch? I would want a set up that is safe and is in accordance with building codes.

The short answer is of course you can.

The short and accurate answer is: it depends on what version of electrical code your state is using. In the newer 2017 version of NEC, they have added and clarified a lot of things about electric vehicles that weren't really covered or specific before. One of those changes says that if a receptacle is being installed for electric vehicle charging, it must be the only thing on that circuit. So if your state has adopted NEC 2017, then no, you can't parallel a wall connector and outlet on the same 50A branch circuit.

The best way to connect two non-concurrent loads to one circuit is a double throw safety switch. Notice the one linked below has a lever action that is ON / OFF / ON. That way only one device can be powered or a device can only be powered by one source.

Besides just being good practice, this allows you to meet that requirement of a single dedicated connection on the circuit. By having an exclusive either/or switch, it meets that checks that box that there will only be one device on that circuit at a time.

 

[davewill]

The best way to connect two non-concurrent loads to one circuit is a double throw safety switch. Notice the one linked below has a lever action that is ON / OFF / ON. That way only one device can be powered or a device can only be powered by one source.

GE 60 Amp 240-Volt Non-Fused Indoor General-Duty Double-Throw Safety Switch-TC35322 - The Home Depot

Of course, this does not resolve the 50A vs. 60A issue.

You could also add a small load center after the switch to hold a 50a breaker. You might find it a bit pricey by the time you add a switch AND a load center to hold the breaker, though.

 

[miimura]

You could also add a small load center after the switch to hold a 50a breaker. You might find it a bit pricey by the time you add a switch AND a load center to hold the breaker, though.

Yes, you could mount the 14-50 in an RV panel to get the proper 50A breaker size for the 14-50 socket onto the 60A circuit after the double throw switch. That will be another ~$100.

GE RV Panel with 50 Amp RV Receptacle and 20 Amp GFCI Receptacle-GE1LU502SSP - The Home Depot

 

[brkaus]

Yes, the Wall Connector is on a 60amp breaker. So if I want a 14-50 next to the Wall Connector, the electrician would have to run a new and separate line from the breaker box? What amp size should the breaker be for the 14-50 outlet?

That would be ideal as long as there is capacity in the panel. 50a breaker.

you could also put a sub panel.

really depends on the house layout, existing breakers, power use of the house.

 

[Akikiki]

Good thread. Very useful information. Thanks everyone. Particularly Rocky_H

 

[Tessaract]

Yes, the Wall Connector is on a 60amp breaker. So if I want a 14-50 next to the Wall Connector, the electrician would have to run a new and separate line from the breaker box? What amp size should the breaker be for the 14-50 outlet?

Of course, you could always install a 50A breaker while you're using the 14-50.

 

[TampaRich]

The configuration OP is asking about is exactly what I had installed 4 years ago. No special adapters or splitters required, just a pass-through from the Nema 14-50 to Tesla wall charger.

 

[brkaus]

The configuration OP is asking about is exactly what I had installed 4 years ago. No special adapters or splitters required, just a pass-through from the Nema 14-50 to Tesla wall charger.

What size breaker do you have?

 

[jerry33]

Yes, the Wall Connector is on a 60amp breaker. So if I want a 14-50 next to the Wall Connector, the electrician would have to run a new and separate line from the breaker box? What amp size should the breaker be for the 14-50 outlet?

The 14-50 needs a 50 amp breaker. As I assume they will be located near each other, it won't be much more expensive to run a second set of wires through the same conduit. I suppose you could have a switch to a new panel so that either that or the HPWC connected, but I believe that would be far more expensive than running a second 50 amp circuit.

 

[DCGOO]

The configuration OP is asking about is exactly what I had installed 4 years ago. No special adapters or splitters required, just a pass-through from the Nema 14-50 to Tesla wall charger.

I have two Wall Connectors (configured w load sharing) and a 14-50 outlet all on a single 60 amp circuit. My two cars are configured to charge at 48 amps each. I rarely use the 14-50. It is up to me to not overload the circuit and pop the breaker.

 

[brkaus]

I have two Wall Connectors (configured w load sharing) and a 14-50 outlet all on a single 60 amp circuit. My two cars are configured to charge at 48 amps each. I rarely use the 14-50. It is up to me to not overload the circuit and pop the breaker.

Problem with that setup is that the 14-50 is rated for 50a. So, technically it could melt and short or the device connected could melt at 58a while the breaker would happily stay on.

 

[ajdelange]

One of those changes says that if a receptacle is being installed for electric vehicle charging, it must be the only thing on that circuit.

I don't have the NEC with me so I can't check but as I recall it says EVSE requires a dedicated circuit. My question would be as to whether installing a transfer switch (e.g. GE 100 Amp 240-Volt Non-Fused Emergency Power Transfer Switch-TC10323R - The Home Depot) and an outlet would be considered adding things other than EVSE.

The determining authority isn't me or anyone else on this site. It's your local inspector. These provisions are new and inspectors that do mostly residential aren't always up to speed as this stuff is more industrial than residential.
I think you have a very good argument as to why this should be allowed. It's obviously safe. A logical inspector would probably accept it. A "book" man might not. Your electrician should knows the local inspectors.

As to the breaker size required for a 14-50R it can be a 50 amp or 40 A.

As to the neutral - I don't know whether you are required to have it or not. Again, your electrician should know. But I will say that whenever I have done or had done new 240V work and did not run the neutral I have come to regret it and in every case where I have run the neutral, even though it was not at first needed I have not regretted the small marginal cost of 3 conductor over 2 conductor wire.

 

[joebruin77]

The configuration OP is asking about is exactly what I had installed 4 years ago. No special adapters or splitters required, just a pass-through from the Nema 14-50 to Tesla wall charger.

Yes, TampaRich, that is exactly the configuration I was thinking of. So I assume you have a 60 amp breaker on the line running from the breaker box to the outlet and Wall Connector?

I understand comments from brkaus and jerry33 that the breaker for a 14-50 should be a 50 amp breaker. If the Model 3 draws as most 32 amps, then in normal operating conditions there would be no danger as long as the Model 3 only draws at most 32 amps. But there is a danger if either the Model 3 malfunctions and draws more than 32 amps or if someone were to plug in another appliance that drew more than 32 amps. Am I correct in understanding that the whole point of a breaker is to provide a backup safety, so that if the car or anything else plugged into the 14-50 outlet malfunctions and draws more than 32 amps, the breaker would "flip"?

So if I am correct, what would be the cheapest way to safely have the configuration that TampaRich has, where the 14-50 outlet is right next to the Wall Connector and each has the 50 amp and 60 amp breaker respectively? It sounds like running a second line with the second line being connected to a 50 amp breaker in the breaker box would be the way to go.

If I do not have the capacity for another 50 amp breaker on my main breaker box, I could then either have my electrician install a subpanel or I could install the 14-50 outlet in an an RV panel with a double throw switch, such as the one miimura recommended? Which would be cheaper to install, a subpanel or a RV panel with a double throw switch?

Thank you,
joebruin77