Emergency charging from a portable generator

[Eric33432]

I installed soft start devices on all our Trane a/c units. They work very well, even though our 60 kW gen set will start our a/c units, the soft start units reduce pretty much completely eliminate flicker and strain on the generator and the compressors and may extend the life of the compressors.

They work by stretching out the time the start capacitor is in the circuit to the start winding into a 4-part start ramp sequence and controlling the current through the start capacitor and start winding using a triac so that the current through the start capacitor and winding is lower than it would otherwise be if it was just across the 240 volt line in series with the start winding. The units I have "learn" the amount of current that is necessary to start the compressor and have reduced the peak starting current by about 3 times.

EasyStart™ 368 Soft Starter

The EasyStart™ soft start motor starter supports 115 & 230V A/C motors & employs a 4-part start ramp sequence that offers the lowest possible start-up current.

www.microair.net

Shown are two units connected to Trane XL20i dual compressor condensing unit. This a/c has two compressors, a 2 ton and a 4 ton, thus requires two soft start units. (Note that only one or the other compressor runs at a time under the control of a two stage thermostat.)

At the time of this screen shot, the 2 ton compressor was operating. Nice day today, about 80˚F:

The app connects to the unit using Bluetooth.

 

[arvindm]

I've got a 23 MYLR that I usually charge on a 60amp circuit via the wall connector outside my garage. I have the mobile connector, and I usually just keep it in my car. Now I'm interested in being prepared in the event of an extended power outage in my area. When I first bought my house, I also purchased this portable gas generator. It's never been used and is still in the box.

I've been trying to figure out if it's possible to charge the Tesla from this, but I'm finding lots of conflicting information. Some sources say it can only be done from an inverter generator (not what I have), some say it can be done but I'll need a ground bonding plug, some say yes I'll just need some sort of adapter.

The highest power outlet on this generator is an L14-30 twist lock outlet at 240v. I found this adapter, which to my untrained eyes appears to be what I'd need to connect to the mobile connector and charge. But I'd like to make sure this is correct before I spend the money on it.

You will probably be able to get 2-3 miles per hour charge at the most. Depends on how many KW your generator puts out in a sustained way, not the peak output.

 

[Midnightsun]

Assuming the generator can output a constant 24A

120v L14 = 10-12 MPH
240V L14 = 20-24 MPH
In both cases, charging input must be set to 24A at the car.

 

[arvindm]

Assuming the generator can output a constant 24A

120v L14 = 10-12 MPH
240V L14 = 20-24 MPH
In both cases, charging input must be set to 24A at the car.

A portable generator will never be able to put out those KW in a sustained manner. A fixed home generator that can produce 32 amps constant will probably charge at the rate mentioned but its touch and go as the voltage and amps fluctuate quite a bit. I have not done it but friends who have a home generator have told me that charging is pretty slow with a generator.

 

[Midnightsun]

The generator shown does 7200W run which is 30A continuous. Only 24A continuous is required for the numbers I mentioned on an L14. No issue unless the generator outputs really dirty power.

 

[wws]

I've got a 23 MYLR that I usually charge on a 60amp circuit via the wall connector outside my garage. I have the mobile connector, and I usually just keep it in my car. Now I'm interested in being prepared in the event of an extended power outage in my area. When I first bought my house, I also purchased this portable gas generator. It's never been used and is still in the box.

I've been trying to figure out if it's possible to charge the Tesla from this, but I'm finding lots of conflicting information. Some sources say it can only be done from an inverter generator (not what I have), some say it can be done but I'll need a ground bonding plug, some say yes I'll just need some sort of adapter.

The highest power outlet on this generator is an L14-30 twist lock outlet at 240v. I found this adapter, which to my untrained eyes appears to be what I'd need to connect to the mobile connector and charge. But I'd like to make sure this is correct before I spend the money on it.

I've successfully tried it using the evseadapters L14-30 adapter you linked to. While the generator I used was supposedly rated high enough that it should have been able to charge at the full 24 amps, it didn't. I had to dial the charging current down to 11 or 12 amps before the car would start charging. IIRC, it was rated at 5.5 kW - so quite a bit less than the 9 kW unit you purchased.

 

[Febtober]

I tried charging it using the mobile connector and the basic 15amp 110volt outlet on the generator, but had no luck. As soon as I'd plug the car in, I'd get an error message to the effect of "communications error with charger" or something similar to that.