We have a Hyundai HY7000LE generator that we can use to fully run the house via a changeover switch during power cuts. It's rated output is 6.3kva (6.9kva peak). Quite some time ago I tried plugging the Tesla UMC charge point into it just to see if it would charge the car ... but no joy, it would always show a fault. I made sure the generator had a good earth but no difference. I knew that when running the house there were never any compatibility issues from any of our electronic devices including routers, computers and TVs so was a bit disappointed it didn't work for the car. I didn't pursue the issue but the other day came across the reason and the solution.
It seems that it is common for generators of this type to have a "floating neutral" rather than a "bonded neutral". This is the issue and the UMC/Tesla won't accept a supply with a floating neutral. The answer is therefore to connect the generator supply neutral to the generator supply earth. All the generator AC outputs are connected together so in addition to where you plug in the UMC you need to connect a spare plug which has the neutral pin connected to the earth pin ... and that's it! I earthed the generator to a pre-existing earthing stake nearby.
For the UMC I already have the additional 16 amp and 32 amp commando adapters to experiment with the load that can be managed from the generator. It turns out that the best match is to use the 16 amp adapter connected to the UMC allowing the car to charge at 4kW as reported in the app. It takes a few minutes of the UMC/Tesla pushing the amps up and then backing off before it settles down to a steady rate. When I used the 32 amp adapter there was a lot of huffing and puffing from the generator as it struggled to maintain a steady rate ... I suspect that if I had backed off the amps on the car charging screen I might have managed a steady 20 amps or so (I also don't know if the generator might be in need of some adjustment to how it manages the automatic control of revs when really pushed continuously.)
I thought my experiences may be of some others who have access to a generator. The likelihood of really needing to charge using a generator is fairly remote but it's interesting to know you can if you have to!
[ @arg had responded to my query about generator charging a long while ago so may be interested to discover the outcome! ]
It seems that it is common for generators of this type to have a "floating neutral" rather than a "bonded neutral". This is the issue and the UMC/Tesla won't accept a supply with a floating neutral. The answer is therefore to connect the generator supply neutral to the generator supply earth. All the generator AC outputs are connected together so in addition to where you plug in the UMC you need to connect a spare plug which has the neutral pin connected to the earth pin ... and that's it! I earthed the generator to a pre-existing earthing stake nearby.
For the UMC I already have the additional 16 amp and 32 amp commando adapters to experiment with the load that can be managed from the generator. It turns out that the best match is to use the 16 amp adapter connected to the UMC allowing the car to charge at 4kW as reported in the app. It takes a few minutes of the UMC/Tesla pushing the amps up and then backing off before it settles down to a steady rate. When I used the 32 amp adapter there was a lot of huffing and puffing from the generator as it struggled to maintain a steady rate ... I suspect that if I had backed off the amps on the car charging screen I might have managed a steady 20 amps or so (I also don't know if the generator might be in need of some adjustment to how it manages the automatic control of revs when really pushed continuously.)
I thought my experiences may be of some others who have access to a generator. The likelihood of really needing to charge using a generator is fairly remote but it's interesting to know you can if you have to!
[ @arg had responded to my query about generator charging a long while ago so may be interested to discover the outcome! ]
