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Tesla J1772 Adapter Melting on a JuiceBox 40

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Hello:

I've got a JuiceBox 40 at home, plugged in to a NEMA 14-50 outlet with a 50A breaker @ 240V. The JuiceBox can do 40A @ 240V or 10kW.

During charging of my Tesla, the J1772 handle gets extremely hot and melts the top right hole of the J1772-side of the adapter.
The UMC side of the adapter is totally fine, no melting. Attached are some photos. Has anyone ever seen something like this?
The handle is connected very securely to the adapter, it clicks into place with the handle lock.
I have already blown through two adapters, so it cant be the adapter, can it?
I contacted AutoChargers.ca in Canada who sells the JuiceBox and they have said that there is nothing wrong with the JuiceBox. I was told by a tesla employee that J1772 handles should have temp sensors on them so that they can turn done amperage in the event of overheating to prevent melting. Perhaps the sensor is damaged.
Any insights?
 
These are a bunch of pictures of the Tesla to J1772 Adapter (supplied with my UMC) with damage all on the top right pin hole.
Two Tesla to J1772 adapters were damaged in the exact same way using this JuiceBox charger.
 

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Last edited:
Either the J1772 handle on the JuiceBox is bad or the Tesla J1772 adapter is bad. The only way to find out is to change one of them and see if the problem reappears. (Though the heat/melting could have permanently damaged the adapter, so even if you get heat using a different J1772 charger it doesn't mean that the adapter caused it.)

I contacted AutoChargers.ca in Canada who sells the JuiceBox and they have said that there is nothing wrong with the JuiceBox.

Did they physically inspect your JuiceBox or how could they possibly know that it isn't defective?
 
I think I’d turn the amperage down to 30A. Most of the J1772s I’ve seen in the wild have topped out at 30A. If one or the other is slightly faulty this may solve your problem.

The 40a ones cost more. They should handle the rated current.

Sure, turning down for 40a to 30a reduces the generated heat by almost 1/2. But it shouldn’t be required...

I do agree most j1772 in the wild are 30a.
 
The J1772 standard currently support 80A and JuiceBox does manufacturer a 75A version of their EVSE so they they may even be using a 80A-capable connector on their 40A device. It's certainly not normal for the 40A model to generate that much heat at the connector.

Given that OP has gone through two adapters already and hasn't indicated the problem occurring on other J1772 chargers I'm inclined to believe it's a faulty J1772 connector on the JuiceBox.

My only other theory is that perhaps an unusual tension on the connector while charging could cause an issue, like if the cord is stretched across the garage instead of draping to the ground from the connector.
 
Contact eMotorWerks directly via their website. Their support has been good for me and I'm sure they will want to be sure there is no systemic issue with Tesla's adapter andtheir EVSE.

I would think this has to be a faulty connector on your JuiceBox or we'd have heard from some of the presumably many Tesla owners using a JuiceBox with Tesla's J1772 adapter.
 
If you have melted 3
The J1772 standard currently support 80A and JuiceBox does manufacturer a 75A version of their EVSE so they they may even be using a 80A-capable connector on their 40A device. It's certainly not normal for the 40A model to generate that much heat at the connector.

Given that OP has gone through two adapters already and hasn't indicated the problem occurring on other J1772 chargers I'm inclined to believe it's a faulty J1772 connector on the JuiceBox.

My only other theory is that perhaps an unusual tension on the connector while charging could cause an issue, like if the cord is stretched across the garage instead of draping to the ground from the connector.
I agree. J1772 connectors (what the OP calls "the handle") do not generally have temperature sensors in them. Tesla connectors sometimes have one depending on the version. All Tesla vehicles have a temp sensor in the inlet but it would be hard to put one in the J1772 adapter.

I would immediately clean the contacts in the J1772 connector using DeOxit or some other electrical cleaner. If that doesn't help then it's probably the wire crimp has come loose or the contact has worn out from too much arcing. I would replace the J1772 connector.
 
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Reactions: GSP
My first guess would be a poor connection between the J1772 handle and the adapter or a loose connection within the handle. Cleaning the contacts would be a good idea, especially the ones in the melted hole, and check that the pin and socket look well shaped. If the J1772 handle comes apart easily you could check the internal connections to make sure everything is tight. Running at lower amps should help everything stay cooler until you find the problem.
 
Well, those are for an inlet, and probably wouldn't fit in the Tesla adapter. Plus he's already tried multiple adapters and a new adapter is cheap enough that it wouldn't make any sense trying to repair it.

Not to mention that those are only 32a pins, which is too low, even if you meant for them to be pins for the plug.
 
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Reactions: hcsharp
This is clear as day: The hot pin is having a bad connection which is causing resistance which is causing the heat buildup... So one of the two connectors is faulty (ether the one in juicebox or in the car). I would highly recommend to stop using this charger until this is fixed. This is fire waiting to happen. The heat on the pins is causing additional wear on the contactor, causing additional resistance and thus additional heat. The amount of heat will only get worse to the point where it catches fire.

This connector/adapter should be replaced ASAP.

If you find the culprit, I would also check out / replace the other side as that is most likely damaged as well. The heat could very well have damaged the "good side" too. For example, its possible that the cable insulation inside your car has melted due to the heat.
 
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Reactions: chibi_kurochan
Did you ever figure out the issue with your EVSE? I'm using a Juicebox Pro 40 with my Model 3, and Juicebox GFI keeps getting tripped. Interestingly, all of these occurrences (so far?) have been while the handle is NOT plugged into the car. I've had the same issue with 3 brand new units, so emotorwerks is now pointing the finger at my charging adapter. Fortunately, I haven't noticed any problems actually charging my vehicle. I will try to visually inspect the Juicebox handle and my charging adapter in closer detail tonight.