L14-30 extension cord

[alt7070]

Hi all, I have a L14-30 extension cord that I use with my generator. I wanted to use it to charge with a UMC 2 and dryer outlet (non-locking 14-30R) when visiting at a friend's house. I looked around and there are several 14-50 to L14-30 adapters (both directions, receptacle and plug), but almost no 14-30 to L14-30.

I could get the adapters and do this:

UMC 14-50P -> 14-50R to L14-30P adapter -> L14-30 extension cord -> L14-30R to 14-50P adapter -> dryer receptacle.

This would require setting the charge to 24A (since it's using the 50A Tesla plug) and removing the neutral on the last adapter to get it to fit in the dryer receptacle. I'd rather get 14-30 adapters, but the seem very rare for some reason. I'm also not a huge fan of multiple adapters, but I was hoping to reuse the generator cable rather than buy a new one (like this one: Heavy-duty NEMA 14-50R extension cord for EV, 30 ft.).

Anyone else using a L14-30 extension cord on trips for the occasional charge? Any feedback?

 

[Kirby64]

Buy the L14-30 adapter from EVSE adapters:
L14-30 Twist-lock Adapter for Tesla Model S/X/3 Gen 2

Then use a L14-30->14-30R (non-locking) adapter. That way you save one adapter and you get the correct current limiting.

That being said, what gauge wire is your L14-30 extension cord? It's probably not too much more expensive to just get a dedicated NEMA 14-50 extension cord... then you're always going to have the right ampacity as needed.

 

[ewoodrick]

You can get 14-30 adapter from Tesla. But then you have the wrong cord. It might be easier to get another cord.

But, unless you know that you are going to need all that current to charge, it may be a lot easier to charge off of 120V (especially 120V 20A with the right adapter from Tesla) and possibly a little bulk charging from a Supercharger or J-1772 site from Plugshare.com.
It's often fun to show off some supercharging while eating. That's what we do when visiting my dad.

Also, always remember, the longer the extension cord, the lower the charge rate.

 

[eprosenx]

Hi all, I have a L14-30 extension cord that I use with my generator. I wanted to use it to charge with a UMC 2 and dryer outlet (non-locking 14-30R) when visiting at a friend's house. I looked around and there are several 14-50 to L14-30 adapters (both directions, receptacle and plug), but almost no 14-30 to L14-30.

I could get the adapters and do this:

UMC 14-50P -> 14-50R to L14-30P adapter -> L14-30 extension cord -> L14-30R to 14-50P adapter -> dryer receptacle.

This would require setting the charge to 24A (since it's using the 50A Tesla plug) and removing the neutral on the last adapter to get it to fit in the dryer receptacle. I'd rather get 14-30 adapters, but the seem very rare for some reason. I'm also not a huge fan of multiple adapters, but I was hoping to reuse the generator cable rather than buy a new one (like this one: Heavy-duty NEMA 14-50R extension cord for EV, 30 ft.).

Anyone else using a L14-30 extension cord on trips for the occasional charge? Any feedback?

So in general, we try to discourage folks from using extension cords regularly (and Tesla says not to do it), however, in on-the-road situations staying at friends houses it just is the most practical thing.

With that being said, the less adapters the better. Each one is a point of failure.

Since the NEC for whatever reason explicitly lists all the non-locking NEMA receptacles as being what you are supposed to use for EV's, the locking ones are really not popular. That might make it hard to use your generator cord (as you are finding).

There is a high likelihood that in your use case I would just buy the following extension cord:

Heavy-duty NEMA 14-50R extension cord for EV, 30 ft. (they also sell a 20' version)

It does not have a neutral pin on the male end so it can plug into a 14-50 or a 14-30 receptacle without modification. Then you can use the Tesla included 14-50 adapter into the UMC. The downside is that the Tesla will think it is allowed to charge at up to 32a, when that circuit is only good to 24a. You would have to manually make absolutely sure to do this when you charge in order to avoid tripping the breaker (or worse, causing a fire if the breaker malfunctioned).

You could also potentially purchase the 14-30 Tesla adapter along with that extension cord and cut the neutral pin off (totally unused by EV's) so you could plug it in to that extension cord. This would result in the safest solution since it would automatically signal to the car the 24a limit.

 

[Petrlol]

If you need longer than 30ft I've used this one multiple times for 6+ hrs at full 32amps and it's been flawless.

Be sure to set your amperage and monitor everything closely!

Conntek 15307 14-50 RV/Generator Extension Cord, 50 - Feet Black https://smile.amazon.com/dp/B07FY691WQ/ref=cm_sw_r_cp_apa_i_WfSOCbJXEPKG2

 

[MagnusMako]

So in general, we try to discourage folks from using extension cords regularly (and Tesla says not to do it)

Been using a 24' extension cord from EVSE with zero issues for the last 4 months.

Also

Also, always remember, the longer the extension cord, the lower the charge rate.

I'm using 50 foot worth and my charge rate is the same as before. I'm sure at higher lengths it'll decrease though.

 

[alt7070]

Thanks all, very helpful info. Kirby64, it's a 10 gauge wire (40-ish feet).

Weird that the locking plugs/receptacles are not encouraged for EVs. I thought that would be better but, maybe note...?

Petrlol, I may get that cord you mentioned and chop off the neutral on the plug. Probably cheaper than buying all the adapters and safer. I already have the Tesla 14-30 adapter so I'd need to chop off the neutral on that plug too (to avoid having to set the amperage).

 

[eprosenx]

If you need longer than 30ft I've used this one multiple times for 6+ hrs at full 32amps and it's been flawless.

Be sure to set your amperage and monitor everything closely!

Conntek 15307 14-50 RV/Generator Extension Cord, 50 - Feet Black https://smile.amazon.com/dp/B07FY691WQ/ref=cm_sw_r_cp_apa_i_WfSOCbJXEPKG2

So to plug that cord into a 14-30 receptacle you would need to cut off the neutral pin (which would be totally fine for strictly EV use but would be dangerous for other purposes).

Been using a 24' extension cord from EVSE with zero issues for the last 4 months.

Also


I'm using 50 foot worth and my charge rate is the same as before. I'm sure at higher lengths it'll decrease though.

Just because you have not had any issues does not mean that it is not more statistically dangerous. There may only be an issue one in 1000 times, but I can't recommend it for regular use.

To the longer length causing slower charging comment: Unless the Tesla detects too much voltage drop and backs off, it will still charge at the same amps rate with or without an extension cord. The difference would be an extremely minor voltage difference due to resistance of the additional wire.

 

[eprosenx]

Thanks all, very helpful info. Kirby64, it's a 10 gauge wire (40-ish feet).

Weird that the locking plugs/receptacles are not encouraged for EVs. I thought that would be better but, maybe note...?

Petrlol, I may get that cord you mentioned and chop off the neutral on the plug. Probably cheaper than buying all the adapters and safer. I already have the Tesla 14-30 adapter so I'd need to chop off the neutral on that plug too (to avoid having to set the amperage).

I don't know why, but for whatever reason NEC 625 calls for non-locking plugs. <shrug>

 

[BrunoB]

I am planning to use this https://www.amazon.ca/gp/product/B005BNZFQ0/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 and then plug in the UMC's 1450 in it.

Any thoughts on this approach ?


Edit : Just realised that it is rated for 125v, that's not gonna work
Thanks

 

[davewill]

I am planning to use this https://www.amazon.ca/gp/product/B005BNZFQ0/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 and then plug in the UMC's 1450 in it.

Any thoughts on this approach ?


Edit : Just realised that it is rated for 125v, that's not gonna work
Thanks

If you look at the second photo, the labels on the cord clearly say 125/250v. It would make no sense for it to be 125v only with those plugs on it.