Just opened a panel to find a nightmare EV charger install

I went through something similar when I tried to hook up my Grizzl-E Classic last summer. I figured I could handle the 6-gauge wire and a 50-amp breaker myself since I'd done plenty of outlet swaps before. I didn't realize how much heat builds up when you're pulling 40 amps for six hours straight.

After about a month, I noticed a faint burnt plastic smell in the garage. When I opened the sub-panel, I saw the black THHN insulation was already getting brittle and discolored at the lug. It turns out I hadn't tightened the terminal nearly enough. I was just using a standard screwdriver and guessing by feel, wich is a recipe for disaster with these high-draw appliances.

I ended up buying a dedicated torque wrench to hit the exact 50 inch-pounds specified in the manual and switched to a high-quality Hubbell industrial outlet. That loose connection was basically acting like a heating element. For anyone doing this themselves, don't just "snug it up." If you don't have the right tools to measure the tension on those heavy-duty conductors, you're better off paying a licensed guy to come out for an hour. It's alot cheaper than a new house.

I had a similar realization but from the perspective of service capacity. When I put in my ChargePoint Home Flex, I went overboard on the physical install—4AWG THHN inside 1-inch EMT conduit. I thougth I was being the ultimate DIYer until the inspector asked for my load calculation. I totally missed that my 100-amp panel couldn't actually support a 60-amp breaker for a 48-amp continuous draw once you factored in the electric oven and the heat pump. Everything looked clean and professional, but the math didn't add up. I had to pivot and install a Wallbox with a power meter for active load management to avoid a full service upgrade. It was a wake-up call that electrical work isn't just about making tight connections or using the right gauge; it’s about the entire ecosystem of the house. Now I tell everyone that the paperwork and the NEC load calculations are just as vital as the torque wrench.

You're right on the money about that panel entry. I've seen folks skip the strain relief entirely, but a huge detail people miss is the actual plastic bushing on the knockout. If you don't have a proper connector there, the constant thermal expansion of the wire during those 8-hour charging cycles makes the cable rub against the sharp edge of the steel panel.

Eventually, it'll slice right trough the insulation and arc directly to the enclosure. It’s a tiny $0.50 part that prevents a massive failure, yet DIYers skip it every single time they just 'poke' a wire into the box without thinking about vibration or heat movement.

The yellow tape is what kills me. If you're gonna DIY, at least use the right colors or buy the right wire. I've seen guys try to use white neutral as a hot without even marking it, then wonder why the next guy gets zapped. It's that "good enugh" mindset that'll burn a place down. People don't get that these chargers aren't like a toaster or a lamp. You're basicly running a space heater on max for the whole night. If those connections aren't rock solid, you're toast.

Oh man, reading these horror stories makes me so glad I haven't tried to wire mine yet! I'm totally new here and just bought my first EV, so I'm soaking all this up. The part about the torque wrench is wild—I didn't even know you needed a specific one for electrical stuff. Quick question though, if the heat is that intense, does it matter what kind of lightbulbs you have in the garage? I just put in some super bright LEDs and I'm wondering if the extra heat from the panel will make them flicker or burn out faster!