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WTB: Dead Roadster MC240 for charging cable

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gregd

Active Member
Dec 31, 2014
2,716
1,916
CM98
Hi folks,

Since it will get lost on the Wanted part of the forum, I'll try here first.

I'm assembling an OpenEVSE charging box for my Roadster. Instead of the expected J1772 connector, I want to go straight into the Roadster's charge port. The easiest way to get the connector and cable at this point is to find a dead Mobile Connector with a good cable and connector on it, and remove the deceased part. I presume (somebody please stop me if this won't work!) that it has the required wires for the job.

I've asked at the local SC, and also over at Clipper Creek. Neither has anything. Given that these things aren't known for their reliability, I'm hoping that someone has one I could give a new life to.

Thanks,

Greg.
 
Hi folks,

Since it will get lost on the Wanted part of the forum, I'll try here first.

I'm assembling an OpenEVSE charging box for my Roadster. Instead of the expected J1772 connector, I want to go straight into the Roadster's charge port. The easiest way to get the connector and cable at this point is to find a dead Mobile Connector with a good cable and connector on it, and remove the deceased part. I presume (somebody please stop me if this won't work!) that it has the required wires for the job.

I've asked at the local SC, and also over at Clipper Creek. Neither has anything. Given that these things aren't known for their reliability, I'm hoping that someone has one I could give a new life to.

Thanks,

Greg.
This is what I did when my UMC died - cannibalized the Roadster connector and now use an OpenEVSE with it. Works well. Good luck.
 
Neither one of the portable charge cables are "built like a tank". Sorry if that offends some.

Both are built by entirely different companies in different countries. One feature of the Roadster UMC is a ventilation hole on the top of the unit (for the relay) that allows water in. Awesome design.

I could probably give you actual failure rate data of the Model S/X UMC, but I don't have it handy at the moment. I can tell you that it is not inspiring.
 
Interesting, Tony. Not seeing the hole on mine, but I don't use it in the rain so I didn't look too carefully.

Fortunately, I'm just looking for the cable itself and car-end connector, not the part of the active unit. This will go on an OpenEVSE mounted inside my garage where the car is parked. Based on feedback, the OpenEVSE mounting won't be tight, so I can take it with me if needed. The other end is a 14-50 plug. Not as portable, but should work in a pinch.

Still looking... Somebody must have a broken one in the closet somewhere. Please?
 
Interesting, Tony. Not seeing the hole on mine, but I don't use it in the rain so I didn't look too carefully.

Fortunately, I'm just looking for the cable itself and car-end connector, not the part of the active unit. This will go on an OpenEVSE mounted inside my garage where the car is parked. Based on feedback, the OpenEVSE mounting won't be tight, so I can take it with me if needed. The other end is a 14-50 plug. Not as portable, but should work in a pinch.

Still looking... Somebody must have a broken one in the closet somewhere. Please?
why not expand your search to the J1772 adapter cable? those are probably more plentiful and cheaper for your project.
 
Neither one of the portable charge cables are "built like a tank". Sorry if that offends some.
I have to agree with you on that, to the disappointment of the fanboys of each one. They "look" like they're built like a tank, but I'd hate to go into battle with a tank that unreliable.

I could probably give you actual failure rate data of the Model S/X UMC, but I don't have it handy at the moment. I can tell you that it is not inspiring.
I'd be interested in seeing those stats the next time you have them handy. I would guess a 10% failure rate within 2 years.
 
You guys are the experts on electronics / electrical layouts, and even though you may say the MC240 its not built like a tank, it is, in my opinion very VERY reliable. I used my MC240 for years as my dedicated home charger which I used daily and it never let me down. Only reason I decommissioned it was that the wire clamp on the Roadster end of the wire by the connector had popped off. I ended up trying to put a hose clamp there, well don't ever do that. Not enough clamping force. Not even close. Henry said you need a very high pressure camping press to get it locked on right. Anyways the hose clamp started cutting into the wires. I tried taking the connector off to fix and its almost impossible from my knowledge to take it apart and put it back together. I also found a broken part inside the connector.... I had a UMC that was my dedicated mobile charger. So I began using that as my dedicated home charger. Well that thing burned out in 8 months of use. Junk. And that hole that's on the top for the relay, well I think that's just there to let the magic smoke out or the genie where you ask for a wish to have a charger that's built of good quality. The MC240 also has more copper in the wires, the housing is built well even though its plastic but its not going to really break on you. Feels solid. And its serviceable unlike the UMC. Those are the qualities I believe people are saying its built like a tank, meaning built well and hasn't let anyone down. I have not found one post to this day from 2012 and searching the archives TMC regards to an MC240 (or Foundry charger) catastrophically failing on them. I'm sure there's one out there somewhere, but I've never seen one.
 
The MC240 also has more copper in the wires, the housing is built well even though its plastic but its not going to really break on you. Feels solid. And its serviceable unlike the UMC. Those are the qualities I believe people are saying its built like a tank, meaning built well and hasn't let anyone down. I have not found one post to this day from 2012 and searching the archives TMC regards to an MC240 (or Foundry charger) catastrophically failing on them. I'm sure there's one out there somewhere, but I've never seen one.

My roadster UMC is potted and is not very serviceable; did they just use a conformal coating on the PCB of the MC240 or is it potted? If it is potted like the 2.x UMC then it is unserviceable. I thought the IP rating of the housing was tied to them potting the electronics.
 
I had a UMC that was my dedicated mobile charger. So I began using that as my dedicated home charger. Well that thing burned out in 8 months of use. Junk.
So, I've been using mine for 2 years now as the primary home charger, and it's been just fine. Never used it outdoors, so perhaps that's a factor, and due to the limited current I could draw from the 10-30 dryer plug, it's been only used at a 24 amp charging rate. I'm suspecting it's that lower current load that has led to its apparent reliability (that's kind of a universal reliability factor, no?), so even though I now have a full 14-50 plug, I still keep the charging load light.

Anyway, the reason for replacing the UMC is just that history of unreliability, especially with a higher charging current now possible, and the desire to save it for occasional travel. Still looking for the cable and connector...
 
I used 220v@30amps on my UMC when charging, the main electrical part of the UMC with the reset button was always inside the house and the cable routed to the outside.
When they fail, what part tends to do them in? (I understand they're not serviceable, just curious where the weak spot is.) My guess is the main relay contacts... Am I close?
 
My UMC would fail due to fault that needed to be reset at the UMC or a fault from the UMC kicked off at the Roadster. It would charge the car sometimes, other times it would charge and then stop shortly. I started thinking that it was my Roadster but deduced if when I used another charge cable. Another Roadster had the same issues with my old UMC as well. Ended up cutting off the cables for backup.

There's a thread on TMC where a person did a tear-down which I added below and goes into why it failed:

"the failed component is a solid state (tantalum? cap), its very clearly smoked."

Journey to the center of the Roadster UMC
 
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So what would cause the cap to fail? From my experience, electrolytic caps fail if subjected to too much heat over time, or if they are under-rated (voltage), or through mechanical abuse (not likely if so well potted). They can also fail if not used for a long time (years), then subjected to full voltage, which is also unlikely in this scenario.

If this is on the low voltage part of the board, not near anything that would be affected (heated) by the charging current, then it sounds like it's an under-rated part for the environment it's in, which means all units are ultimately doomed. Unless they've updated the failing components over time. Any date code history or the like? Mine says the following on the back. Looks like a product # and S/N.

06-002837-00
6005168

I didn't see any notes on the ones that were dismantled, however. Did you happen to scribble that down somewhere?
 
That fits, except potentially (hopefully) for the timeframe. I would hope that by 2010 (assuming the UMC and car were manufactured at somewhat the same time), the whole thing would have been sorted out. Ok, so they probably did a bulk build of UMCs early on and stocked them, so that's not going to be true... Still, the issue would have been well known before any of these were built, yes? If so, hopefully the development team would not have used such parts. Otherwise, they're all doomed.

I guess a small bit of good news from Wiztecy's post is that the failure appears to be somewhat gradual, i.e. it gets flakey before totally failing. So, if you're depending on it for a one or two charges during a short trip, you're not likely to get stranded. Also, there's no indication (right?) that the UMC degrades while not being used, so not using it on a daily basis will extend its calendar life and the likelihood of it performing correctly during a trip.
 
A tantalum or electrolytic capacitor of any size is probably part of the power supply to run the electronics. It could be a TVS that's designed to provide protection from a voltage spike or surge. If it's part of the power supply then your charging rate (40A vs 24A for example) will have no effect on lifespan.