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Discussion Starter #1
My 14 came with a Lear EVSE, the same that many here have had issues with. Ive used it a good bit and never had many issues with it until one day it gave me a ground fault error. I couldn't get it open so I gave it a calibrated technical tap and it started working again. Months go by. On a whim, I decided to replace the input cord with a longer cord to make it easier to user. In the process of getting it open, I pretty much destroyed the case. It was high frequency and/or solvent welded closed. Once I got it open, this is what I found:

Lear EVSE Roasted.jpg

Upon further investigation, I decided to cut apart the input cord.

Lear EVSE Cord Burned.jpg

I have a couple theories why the Lear EVSE got a bad rep. I also figured out why my EVSE triggered a ground fault then started working again. As you can see from the inside of the case, the input leads are roasted. This is understandable because of the current draw however I noticed something that did not make sense. The output cord has 16 gauge wire but the input is 14 gauge. For simplicity sake, I am going to assume the that the current on both input and output conductors is the same. (in reality, the input current is less than 1% higher so its not worth considering) Since the output wires are smaller, they should generating more heat but this is not the case as judged by the heat damage.

I believe that Lear or whoever made their input cord assemblies got a bad batch of 14 gauge copper. Maybe it wasn't electrical grade or contaminated with oil or something else. The connections were the source of heat and this heat caused the insulation to break down the insulation. Typically this gives off free fluorine and chlorine gas and this will attack the copper. I base my belief on a couple things.

-The 16 gauge wires did not burn.
-All the heat appears to originate at the connections. On the plug end, the ground wire cooked due to heat conducted from the hot and neutral. Inside the case, it did not cook.
-The ribbon wire to the display board has this green oily substance on it and a melted spot where it was leaning against the neutral wire. This is where I believe the ground fault came from. The oily substance contains copper chloride. The copper source is obvious, the chlorine I believe came from the decomposition of the insulation.
-Though its possible that the insulation could have out-gassed chlorine and/or fluorine due to being improperly cured during manufacture, I dont think this is the case because the inside end of the ground wire is not corroded. I believe the root cause is contaminated copper.

That aside, here is what I did to fix it. It will be in the next post because I cant post enough pics in the same message.
 

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Discussion Starter #2 (Edited)
Since the case was distroyed when attempting too open it, I bought a metal box to put it in. The lid I did some machining to make a hole for the LED display and an o-ring groove for the original seal. I used the original plastic window. I also discovered that the display board has a second row of LEDs that show charge status and more fault data.


Once machined and the window and board cleaned up, using a urathine sealent, I glued the window to the lid with the oring in the groove.

Lear EVSE Lid.jpg
Lear EVSE Lid Assembly.jpg

Countersunk flathead screws were used to attach the board to the lid. The threads were sealed with the same urathane. The same technique was used for the main board in the case. The input cord was replaced with a 3 ft 12 gauge SO cord. The existing 16 gauge cable was reused for 3 reasons: 1, it worked fine and 2, I could not source 14/3 + 20/2 or anything like it and 3, the cable was potted into the J1772. Both cords were sealed into strain reliefs and they were sealed with urethane.

Lear EVSE Open.jpg
Lear EVSE Closed.jpg

The box I chose was o-ring sealed. Once closed and powered up, this is what it looks like:

Lear EVSE Finished.jpg

A few additional notes:
-I used nylon standoffs, bushings and washers for mounting the boards to make certain that it is isolated. The prior case was plastic so it did not matter.
-I noticed that the EVSE when booting, the ground is not passed through to the J1772 until it is determined that there is no potential for leakage or fault current.
-When sealing the window to the lid, I clamped it overnight to make sure it got a good bond. Only the sealant around the outside is making the seal. The spot in the middle is there just to help hold it on.

I have not yet tried it on 240V but from what I have read, it will work fine. The input terminals on the board are labeled as L1/H and L2/N. Also I found a youtube video where someone used one just like mine on 240V with no issue. (cant find the video) Though I probably shouldn't have, I moved the nameplate sticker showing power ratings as well as the NRTL certification to the new case.

So in conclusion, I think the Lear EVSE gets a bad rap because of the poor quality input cord. If that cord is replaced, I think it would be fine. Simply replacing the plug will not work. Had I tried that, I would have discovered how cooked the wires were and this would have sent me down the road to replacing the cord. As for others that have these and have failed, I think it could be because one of the input wires melted and shorted to the ribbon.

I'm happy to share any part numbers I used if anyone is interested.
 

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Links for attachments aren't working, but it might be my computer...
 

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Nice job, thanks for the pics and details.

My Lear-built L2 Voltec unit died after 12 months, 7 days. It did not have the cooked wires of your L1 unit, but others with the L1 unit have posted similar pictures to yours with cracked wire insulation. I don't know if Lear just went lowest bidder for the components and got marginal quality cords and other components as a result, but there were a fair number of failures and ultimately all the early units were recalled.

Another common failure was the stress relief on the charge cord where it exited the case. These were made of semi-flexible plastic (not rubber) and they all cracked off within a year or so of use, meaning no stress relief on the cord as it was bent again and again at a 90° angle with repeated use.
 

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Yep, Attachments now show. Good work on the repair.
 

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Well done.

With EV charging we are running at these current levels continuously for a long period of time and it does require that these things be of a decent quality. Myself and some others often emphasis the use of good quality electrical outlets and wire for the home side.
 

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Discussion Starter #8
Well done.

With EV charging we are running at these current levels continuously for a long period of time and it does require that these things be of a decent quality. Myself and some others often emphasis the use of good quality electrical outlets and wire for the home side.
Agreed.

What I usually tell other EVers is
-Replace the receptacle with either a Hubbell or Leviton 120V 20A that is commercial or hospital grade.
-Replace the plug on the EVSE with either a Hubbell or Leviton 120V 15A that is commercial or hospital grade
-The circuit wiring must be 12 gauge, preferably 10 gauge especially if the run is over 60 feet.
 
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