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I've noticed that when charging my Tesla on my 40A OpenEVSE, after a while the EVSE limits the charge rate to 20A because it has gotten over 60C.  It stays at 20A for 5 minutes or so, then goes back to 40A for 10 minutes, then back to 20A. Up and down.

I don't think this is a problem, but it does mean that the car charges a little more slowly than it could, since it averages 33A while in this mode.

However, I notice that the OpenEVSE case is a sealed enclosure.  Given that my unit is mounted inside my garage, far from any door or window and not going to get wet, would it be useful to cut some ventilation holes in it for cooling?  I'd probably put them on the side, one near the bottom and one near the top.

Does anyone see any issues with this?

Oh, it's also worth mentioning that the 33A average is at current temperatures (springtime).  In the summer when the garage is hotter, I expect the reductions to be longer and more frequent, and the net charging rate slower.

Hmm. My kit came without the lugs, so I cut the ferrules off, stripped the wires and wrapped the wires around the screws. Everything should have really good contact.

I'll let it warm up and then disconnect and open it up and see where the hot spots are.

The argument against ventilation makes sense.

It's the relay (Struthers & Dunn) that's getting hot. The hottest parts of it are the low-voltage screws, which seems odd.  My infrared thermometer measured them at about 160F right after I opened the cover. The input and output terminals were all about 145F.

Thanks!  Could you also send new wires?  I cut the ends off of mine.  Do you need an address?

I live in Scottsdale AZ and I'm seeing throttling down from 24A to 12A due to high temps.  I've gotten into the habit of directing a room fan at it while it runs.  It seems to do the trick.  I would prefer some sort of beefier built-in cooling option for the EVSE though.

I finally got around to updating my firmware yesterday to the latest version - 5.0.1.  I plugged my car in last night and came out to a red-backlit display that indicated the unit had gone over temp.

While I had the unit open, I put ferrules on the high-current feeds in and out of the relay, so I'd say I've eliminated that possibility.  Ambient temp in the garage was around 98F when I started charging.  It would appear that I have one of the displays that is overheating, but I don't have an IR camera to check.

My workaround will have to continue to be directing a fan at it, as that's what I've been doing up to this point.

Wondering if this thread is still active?

I've had heat/shutdown issues since charging my new Leaf SV+.  I've changed a bad spade connector and throttled back to 24 amps, but still have issues with the unit shutting down during a long charge.  At 22 amps, the unit gets up to about 110-115 oF at the front surface below the LCD screen.  The "menu" button gets quite hot.  The latest internal issue was a blown fuse with obvious heat damage around the upper terminal of the "white" wiring terminal block - along with an obvious burn smell inside the unit.  

Do you have any suggestions - I've replace the fuse, ensured good connections and taken the IR temps given above.

Mark