Nema 10-30 converted to TT-30

[billhein94]

I may be asking a question that has been asked already, but my searches have been unsuccessful.

I have an available TT-30 receptacle that I would like to use on occasion to charge my Tesla Model Y. I mistakenly bought the Nema 10-30 adapter from Tesla. I now know the difference.....I work in the electrical/electronics field, and am confident in my ability to figure this out, I am just having a hard time finding any sort of information or wiring diagrams on the adapter. Soooo.....my questions are:

Could I cut off the 10-30 connector and replace it with a TT-30 connector? I have seen the Tesla adapters for sale without the connector, but they are sold out......are all the 24A versions the same just wired to a different connector?

I guess I really need to know which wire goes to which pin on a TT-30 connector. Anybody have any experience with something like this?

 

[CKwik240]

I'm going to build onto this thread as it has some good discussion already.

Background:
I took a camping trip this weekend. It was a one night stay at an RV site with a TT-30 connector. I've never used one of these plugs until this weekend. This was kind of a last minute decision to go and so I only had time to order a TT-30 to NEMA 14-50 adapter:

https://www.amazon.com/dp/B07MD41D45?psc=1&ref=ppx_yo2ov_dt_b_product_details

While it worked just fine electrically, since the connector pushed the head of the Mobile Adapter connector out a few inches and the cord ultimately sticks out perpendicular to the outlet face, it tends to pull down on the connection. My spot had an outlet that was somewhat loose so it would not stay connected unless I wrapped the cord over the pedestal. It worked. The second problem was that it didn't switch charge speed automatically. I forgot I needed to do this and since it worked initially, I wasn't reminded that this was necessary. I got about 50 miles of range before it started having issues. Never tripped the breaker and I'm guessing the thermal protection finally kicked in. I was getting about 13 mi/hr for some time. It didn't become apparent that there was an issue until the next day. Thankfully, the campsite wasn't far from civilization and with the 123 mi of range I had, I was able to do some sightseeing before heading over to a supercharger and then heading home.

So the most ideal solution is the EVSE Adapters TT-30 cable. But, I'd like to explore another option first. Obviously, the adapter I bought isn't the best solution and even an adapter that uses an intermediate cable still puts one more set of connectors in-between and the thermal sensor will only be detecting heat problems at the 14-50 or 10-30 connector.

I have an extra 10-30 connector as I had bought one when I got my Model 3 to charge rather than the whole set as they did not have the whole set available at the dealer and were sold out online. I have since bought the set. My plan is to cut open this connector and try to see if I can salvage the thermal protection circuit and the wiring such that I can add a TT-30 plug and attach the thermal protection circuit inside the plug head. Based on the EVSE Adapters pigtail photos, it looks like its a thermistor or thermocouple in the head. Ultimately, this would only cost me the price of a TT-30 plug and auto-switch the current to 24A.

My question is does anyone know if anyone has cut the head open before? It would be helpful to know if there are any reasons that this idea would be possible/practical, and ifs its been done before, it would give me a bit of a roadmap to how to cut this apart and avoid unnecessary damage. I'd rather not go in blind if I don't have to. TIA.

 

[jcanoe]

I'm going to build onto this thread as it has some good discussion already.

Background:
I took a camping trip this weekend. It was a one night stay at an RV site with a TT-30 connector. I've never used one of these plugs until this weekend. This was kind of a last minute decision to go and so I only had time to order a TT-30 to NEMA 14-50 adapter:

https://www.amazon.com/dp/B07MD41D45?psc=1&ref=ppx_yo2ov_dt_b_product_details

While it worked just fine electrically, since the connector pushed the head of the Mobile Adapter connector out a few inches and the cord ultimately sticks out perpendicular to the outlet face, it tends to pull down on the connection. My spot had an outlet that was somewhat loose so it would not stay connected unless I wrapped the cord over the pedestal. It worked. The second problem was that it didn't switch charge speed automatically. I forgot I needed to do this and since it worked initially, I wasn't reminded that this was necessary. I got about 50 miles of range before it started having issues. Never tripped the breaker and I'm guessing the thermal protection finally kicked in. I was getting about 13 mi/hr for some time. It didn't become apparent that there was an issue until the next day. Thankfully, the campsite wasn't far from civilization and with the 123 mi of range I had, I was able to do some sightseeing before heading over to a supercharger and then heading home.

So the most ideal solution is the EVSE Adapters TT-30 cable. But, I'd like to explore another option first. Obviously, the adapter I bought isn't the best solution and even an adapter that uses an intermediate cable still puts one more set of connectors in-between and the thermal sensor will only be detecting heat problems at the 14-50 or 10-30 connector.

I have an extra 10-30 connector as I had bought one when I got my Model 3 to charge rather than the whole set as they did not have the whole set available at the dealer and were sold out online. I have since bought the set. My plan is to cut open this connector and try to see if I can salvage the thermal protection circuit and the wiring such that I can add a TT-30 plug and attach the thermal protection circuit inside the plug head. Based on the EVSE Adapters pigtail photos, it looks like its a thermistor or thermocouple in the head. Ultimately, this would only cost me the price of a TT-30 plug and auto-switch the current to 24A.

My question is does anyone know if anyone has cut the head open before? It would be helpful to know if there are any reasons that this idea would be possible/practical, and ifs its been done before, it would give me a bit of a roadmap to how to cut this apart and avoid unnecessary damage. I'd rather not go in blind if I don't have to. TIA.

Your could make up a custom extension cord with a male TT-30 connector and a 10-30 female connector. Connect the hot lead from the TT-30 to one side of the 10-30. [Edited] Use the other hot connection on the 10-30 for the neutral connection from the TT-30, i.e. wire the neutral connection from the TT-30 to what would normally be the second hot connection of the 10-30. Wire ground to ground.

 

[Rocky_H]

Your could make up a custom extension cord with a male TT-30 connector and a 10-30 female connector. Connect the hot lead from the TT-30 to one side of the 10-30 and leave the other hot connection on the 10-30 unused. Wire the neutral connection from the TT-30 to the neutral connection on the 10-30.

That wiring setup won't work. You say to take the hot from the TT-30 to the hot of the 10-30 but to leave the other hot side of the 10-30 unused. But those are the only two pins the Tesla 10-30 plug is looking at for voltage, so it will see an open circuit and get nothing. When you are trying to flip from a 120V source to a 240V outlet, you can't connect Neutral to Neutral. That neutral is one of the sides of the voltage source, so it has to go on the other side as if you're connecting to Hot1 Hot2 of a 240V receptacle.

 

[CKwik240]

Your could make up a custom extension cord with a male TT-30 connector and a 10-30 female connector. Connect the hot lead from the TT-30 to one side of the 10-30. [Edited] Use the other hot connection on the 10-30 for the neutral connection from the TT-30, i.e. wire the neutral connection from the TT-30 to what would normally be the second hot connection of the 10-30. Wire ground to ground.

Sure. That is what the OP did. But as I mentioned, its another cable added to an existing cable which also means 1 extra connection and the thermal protection is only limited to the 10-30 plug. Replacing the plug on the 10-30 could allow me to retail the thermal protection if I can get it out intact. Plus, its just a cleaner solution since I have no need to keep this spare 10-30 intact.

 

[jcanoe]

Sure. That is what the OP did. But as I mentioned, its another cable added to an existing cable which also means 1 extra connection and the thermal protection is only limited to the 10-30 plug. Replacing the plug on the 10-30 could allow me to retail the thermal protection if I can get it out intact. Plus, its just a cleaner solution since I have no need to keep this spare 10-30 intact.

If you plan to regularly park at an RV campground that has TT-30 receptacles wouldn't it make sense to purchase the EVSEAdapters TT-30 plug adapter for the Tesla Gen2 Mobile Connector. An RV campground with 14-50 receptacles would be even better. Good luck with your 10-30 plug adapter conversion project.

 

[CKwik240]

If you plan to regularly park at an RV campground that has TT-30 receptacles wouldn't it make sense to purchase the EVSEAdapters TT-30 plug adapter for the Tesla Gen2 Mobile Connector. An RV campground with 14-50 receptacles would be even better. Good luck with your 10-30 plug adapter conversion project.

It would be the same thing ultimately. But if I can do it, it would only cost me $20. If I just bought it, It would cost be $100 and maybe get a little back if I sell the spare 10-30. Plus it would be kind of fun.

 

[CKwik240]

So I went ahead and tried to open up the 10-30 connector. I wouldn't recommend it. The side where the prongs protrude from appear to be held to the shell. But the backside looks to be injection molded into this casing with the wires in place so it's pretty much a solid block of plastic. I suspected this may have been the case but since I could not find any info as to how it was put together, I wanted to see for myself. It's unlikely I can remove the sensor intact and cleanly. I attached a few photos. I started grinding the back with my angle grinder bit broke the blade in the process. I didn't get any photos of that yet (I didn't get very far anyways, as I was doing it during some downtime while replacing my meter panel at home) but will put some more up when I have a chance pick up a new blade and keep going. I did get down to the backside of a couple prongs and they are definitely encased. I'll still try to see how far I can get and my plan was to encase the sensor anyways to help with heat transfer to the sensor, but it might be hard to remove it without damage since I can't see where exactly it is and what it looks like. Wish I had access to my parent company's x-ray or ct scans...