Nema 14-50 splitter?

[Gutta420]

Hey all. Just wondering about using a splitter like the one in the pic I posted. Wondering if anyone here had the same setup. I have a c40 recharge and now that my model 3 is imminent I need a solution other than installing another 14-50 outlet. I will if I have to but I'm trying not to spend that money again.

So a few questions. First & foremost, is it safe? Fire risks? I assume it'll split the power between the two so charging speeds for both would be halved which would be fine as it would still be faster than a standard 120. Will charging two cars on the same circuit potentially overload things and to the breaker? Thanks in advance for any help or suggestions.

 

[Kandiru]

Very bad idea, and a fire hazard. My 40A wiring is entirely contained inside metal tubing all the way to the wall receptacle. Putting my
hand on the tubing I can feel the heat emanated by the wiring when under load.

On one of our garages I have two NEMAs in parallel, in case we have EV visitors, never use both, and signs on each state that.

Be safe!

 

[Sophias_dad]

Ya.... not a good idea. It won't split any power between anything. If both devices ask for 32 amps(or even 50) they'll get it. The best case is that the circuit breaker will trip. The worst case is your new splitter goes up in flames before that happens. If you use two UMCs(or equivalent) you'll get 64 amps through that splitter, and it could take a while for the breaker to trip, perhaps even minutes.


But yes, if you only use one or the other charger at a time, it would be fine. I could see doing that with scheduled charging, where you plug in both and set the Tesla to only charge after the other one is done(this assume the other is not auto-charging every now and again after it is fully charged)

 

[Gutta420]

Very bad idea, and a fire hazard. My 40A wiring is entirely contained inside metal tubing all the way to the wall receptacle. Putting my
hand on the tubing I can feel the heat emanated by the wiring when under load.

On one of our garages I have two NEMAs in parallel, in case we have EV visitors, never use both, and signs on each state that.

Be safe!

Thank you! That was my main concern, it being a fire hazard. Well, I guess I have to have another dedicated line ran on a separate circuit.

 

[robaross]

You could try this:

NEMA 14-50 Smart Splitter + Wifi

The fastest and easiest way to get charging installed for your Tesla at home. Shop now for free shipping and exclusive deals.

store.getneocharge.com

 

[Gutta420]

But yes, if you only use one or the other charger at a time, it would be fine. I could see doing that with scheduled charging, where you plug in both and set the Tesla to only charge after the other one is done(this assume the other is not auto-charging every now and again after it is fully charged)

Yea see that to me defeats the purpose of spending $100+ on this splitter. I could just unplug one and then plug the other in if that the case, I was looking for a solution to charge both at the same time. Ah well, like the other poster stated and you reiterated…it’s a fire hazard. I’ll go the route of charging one at a time for now until I get another dedicated 14-50 installed. And yes, the c40 does trickle charge after it reaches my limit (90%) to keep it there depending on how long it sits after the limit is reached. Does the tesla not do this?

 

[Gutta420]

You could try this:

NEMA 14-50 Smart Splitter + Wifi

The fastest and easiest way to get charging installed for your Tesla at home. Shop now for free shipping and exclusive deals.

store.getneocharge.com

Man I was super excited until I clicked on it and saw that price. Talk about sticker shock lol…was NOT expecting that. For that price I’m just going to get another 14-50 installed.

 

[jdcollins5]

I have one for my wife’s Pacifica plug-in hybrid. We only plug in at night for off-peak charging. She only uses the dryer in the mornings.

Note: I am a EE and fully aware of the issues if not used correctly. I chose not to pay $500 for a two breaker box to switch between the two.

 

[!igs]

I assume it'll split the power between the two so charging speeds for both would be halved which would be fine as it would still be faster than a standard 120.

That's not how circuits work AT ALL. Instead of drawing 40 amps from the outlet it will draw 80 amps.

I wouldn't call it a hazard either since your circuit breaker will simply trip.

It will work if you only charge one car at a time.

 

[!igs]

Very bad idea, and a fire hazard. My 40A wiring is entirely contained inside metal tubing all the way to the wall receptacle. Putting my
hand on the tubing I can feel the heat emanated by the wiring when under load.

THAT sounds like a fire hazard. Are you sure you used the correct wiring?

 

[jrweiss98020]

That's not how circuits work AT ALL. Instead of drawing 40 amps from the outlet it will draw 80 amps.

I wouldn't call it a hazard either since your circuit breaker will simply trip.

IF he sets the app for 20A max on each car, it will work. HOWEVER, I don't know if I would trust the app to retain the setting...

 

[robaross]

The smart splitter goes with YOU if you move. Your box may not have enough room for another breaker, or it can't handle the load. Also, neo-charge will work with you a little on price if you ask.

 

[!igs]

IF he sets the app for 20A max on each car, it will work. HOWEVER, I don't know if I would trust the app to retain the setting...

He said power split is halved. It's not. Power through the outlet is doubled when you have a parallel circuit.

 

[Sophias_dad]

And yes, the c40 does trickle charge after it reaches my limit (90%) to keep it there depending on how long it sits after the limit is reached. Does the tesla not do this?

Once the Tesla is charged to the requested level, it will stop charging. After a few hours or a day it'll start charging again at its full rate(lets say 32A) for maybe 10-15 minutes, repeating as necessary to stay within 3-4% of your desired target(approximately). The percentage has changed over the years.

 

[Sophias_dad]

I could just unplug one and then plug the other in if that the case, I was looking for a solution to charge both at the same time.

Ya, but that outlet will wear out quickly. 14-50's aren't usually designed to be plugged/unplugged hundreds of times. You can probably do it much more often with a hubbell/bryant/cooper, but a leviton will try to burn your house down after a while.

 

[Rocky_H]

Man I was super excited until I clicked on it and saw that price. Talk about sticker shock lol…was NOT expecting that. For that price I’m just going to get another 14-50 installed.

Adding an additional 50A circuit might get expensive--depends if your have enough spare capacity for it. So another option might be that you could split up that 50A circuit you already have allocated there into a 30A and a 20A. That would be full code compliance and not dangerous and you could keep both cars plugged in all the time whenever you want, and it wouldn't be an issue.

 

[Gutta420]

Adding an additional 50A circuit might get expensive--depends if your have enough spare capacity for it. So another option might be that you could split up that 50A circuit you already have allocated there into a 30A and a 20A. That would be full code compliance and not dangerous and you could keep both cars plugged in all the time whenever you want, and it wouldn't be an issue.

That may work actually. Quick question... obviously it will charge slower but would it basically be equivalent to a standard 110 because I know some 110's are 20 amp and others are 15. So at that point it'd probably make more sense to just plug it into a 110 huh?

 

[Rocky_H]

That may work actually. Quick question... obviously it will charge slower but would it basically be equivalent to a standard 110 because I know some 110's are 20 amp and others are 15. So at that point it'd probably make more sense to just plug it into a 110 huh?

No, quite different. The charging speed scales with power in Watts. That is voltage times amps. So doubling either one of those doubles the power, and therefore doubles the charging speed.

So a 240V circuit at 20A will be double the power of a regular 120V circuit at 20A. So any of these 240V circuits are pretty solid charging speeds, even for the 20 or 30A circuits and are way faster than the standard 120V outlets.

There's another factor too, where the car being on, running the charging has some significant overhead power consumption. And if you're using something really low power, like a 120V outlet, you're losing a pretty significant portion, like a fourth or so of that, just to overhead losses. So getting up to a higher power input has the same overhead loss, but all that extra is bonus into the battery and does really help the charging speed. So double power is more than double for your charging speed when it's getting it above those really low power connections.

 

[cali8484]

I have the the splitter and it works just fine. However, I don't use it to charge 2 different cars at the same time. The splitter is only used to avoid having to plug/unplug which is inconvenient for NEAM 14-50.

 

[Brenzo]

Adding an additional 50A circuit might get expensive--depends if your have enough spare capacity for it. So another option might be that you could split up that 50A circuit you already have allocated there into a 30A and a 20A. That would be full code compliance and not dangerous and you could keep both cars plugged in all the time whenever you want, and it wouldn't be an issue.

I am trying to do something like this, but the electrician quoted $800, which is more than I paid to install the original outlet that required pulling power from the panel to the garage.

He said to take the existing 14-50, install a 50 amp breaker box where the outlet is then run (2) 20 amp 240-volt outlets.

Obviously would lose some charging capacity, but I thought (maybe not?) that it would be cheaper than buying a splitter like SPLITVOLT NEMA 14-30/14-50 SWITCH SPS - Splitvolt or Shop Home Level 2 EV Charging Adapters | NeoCharge