Hack-charging on a generator

[cinergi]

I tried the UMC at 120 and 240 on my new Honda EU6500is and it refused to work at all - the UMC blinked red 4 times (ground loss) -- which makes sense given the generator ground/neutral design. I'll try again when it's connected to my house (and thus really grounded) and report back. I could have also grounded the generator but ran out of time to play with that today.

 

[cinergi]

Successfully charged at 6.5 kW on my EU6500is

 

[wycolo]

Excellent!! What is that interconnect installed to the left of your garage breaker box with cable going to rh outlet on Honda? The Honda manual does not mention any 'whole house' connection schemes.

Home Depot only had (on the shelf) SquareD CGK2C cover plate kit that allows the generator breaker to be ON only when main house breaker is OFF. Kinda basic but for emergencies quite doable. Yours is completely different.
--

 

[AudubonB]

And at how many amps did your Model S screen show it was drawing, Cinergi?

On edit: oops! Hadn't noticed that was a video, not just a screen shot. Thanks.

 

[cinergi]

Excellent!! What is that interconnect installed to the left of your garage breaker box with cable going to rh outlet on Honda? The Honda manual does not mention any 'whole house' connection schemes.

Home Depot only had (on the shelf) SquareD CGK2C cover plate kit that allows the generator breaker to be ON only when main house breaker is OFF. Kinda basic but for emergencies quite doable. Yours is completely different.
--

That's just the L14-30 inlet. That's wired directly to the main panel inside the house using a 30 amp breaker and an interlock kit (so I can't backfeed the grid).

- - - Updated - - -

And at how many amps did your Model S screen show it was drawing, Cinergi?

I think you can see in the video but IIRC I got it up to 26 amps before I hit the max 6500 VA load on the generator.

- - - Updated - - -

A full charge for an 85 kWh pack at 5.5 kW is, I think, about 16 hours. The EU6500is is rated for 4.7 hours on a tank of gas (4.5 gallons) at full load. That's 15 gallons of gas to fill the car for ~250 miles of range or ~17 mpg. :smile: (someone should probably check my math)

 

[mitch672]

A natural gas generator would solve the run time/many runs to get gasoline issue(s), and work as long as the natural has pipelines function.. of course that's a bit more money (not much more though), and an automatic transfer switch, usually. I have an old 8KW Winco NG generator on a 200A transfer switch, paid about $4K for it back in 1996, now they have packaged systems for not much more ($6-8K) that are 15-20KW...

 

[cinergi]

A natural gas generator would solve the run time/many runs to get gasoline issue(s), and work as long as the natural has pipelines function.. of course that's a bit more money (not much more though), and an automatic transfer switch, usually. I have an old 8KW Winco NG generator on a 200A transfer switch, paid about $4K for it back in 1996, now they have packaged systems for not much more ($6-8K) that are 15-20KW...

Yeah it was more an exercise in fun math than anything -- I don't see myself seriously charging the car from the generator ... great way to load test it!

 

[redi]

Cinergi,

Thanks for posting and testing this. I have the same gen/interlock kit for the house and was curious and had not gotten around to a test for hack-connecting it with http://www.amazon.com/dp/B003PY5BVG/ref=pe_385040_30332190_TE_M3T1_ST1_dp_1 if would work (and it won't - and saves $47 to test it) should we have some local electrical apocalypse. But good to know going through the HPWC will indeed work in the same situation.

 

[cinergi]

Cinergi,

Thanks for posting and testing this. I have the same gen/interlock kit for the house and was curious and had not gotten around to a test for hack-connecting it with http://www.amazon.com/dp/B003PY5BVG/ref=pe_385040_30332190_TE_M3T1_ST1_dp_1 if would work (and it won't - and saves $47 to test it) should we have some local electrical apocalypse. But good to know going through the HPWC will indeed work in the same situation.

What you have there would probably work *IF* you grounded the generator (there's a terminal for doing so). I believe that's why it works when I connect via the house (which provides the ground).

 

[mknox]

What you have there would probably work *IF* you grounded the generator (there's a terminal for doing so). I believe that's why it works when I connect via the house (which provides the ground).

This is a guess, but building systems have the Neutral and the Ground bonded together at the service entrance. The Model S might just be looking to see if Ground and Neutral are at the same potential.

 

[cinergi]

This is a guess, but building systems have the Neutral and the Ground bonded together at the service entrance. The Model S might just be looking to see if Ground and Neutral are at the same potential.

HPWC and UMC at 240 don't pay attention to neutral (it's not even physically connected in the HPWC).
Plus the error code I got on the UMC is clearly a "lost ground" error according to the manual.

(though indeed the neutral is floating on the eu6500is -- it's not bonded to ground)

 

[mknox]

HPWC and UMC at 240 don't pay attention to neutral (it's not even physically connected in the HPWC).
Plus the error code I got on the UMC is clearly a "lost ground" error according to the manual.

(though indeed the neutral is floating on the eu6500is -- it's not bonded to ground)

Hmmm. The UMC / HPWC must be "testing" the ground by trying to return a small amount of current from one or both of the 240 volt legs on the ground wire, or by detecting a voltage between the leg(s) and ground. In order for that to work, ground and neutral would have to be connected. This is more of a thought exercise, but it would be interesting to see if the Model S could be charged directly from the generator without having to go through the home. I doubt that just grounding the generator would work if the neutral remains floating.

BTW, I've been looking at reviews of that Honda generator and although expensive, it looks like a really nice unit.

 

[Cottonwood]

Hmmm. The UMC / HPWC must be "testing" the ground by trying to return a small amount of current from one or both of the 240 volt legs on the ground wire, or by detecting a voltage between the leg(s) and ground. In order for that to work, ground and neutral would have to be connected. This is more of a thought exercise, but it would be interesting to see if the Model S could be charged directly from the generator without having to go through the home. I doubt that just grounding the generator would work if the neutral remains floating.

BTW, I've been looking at reviews of that Honda generator and although expensive, it looks like a really nice unit.

Yup, the MS wants to see some sort of ground connection.

I'm a big fan of a pair of Honda 2000i's; good power and you can carry each one...combine with a 120/240 auto transformer and you can get some OK charge rates...

 

[cinergi]

Hmmm. The UMC / HPWC must be "testing" the ground by trying to return a small amount of current from one or both of the 240 volt legs on the ground wire, or by detecting a voltage between the leg(s) and ground. In order for that to work, ground and neutral would have to be connected. This is more of a thought exercise, but it would be interesting to see if the Model S could be charged directly from the generator without having to go through the home. I doubt that just grounding the generator would work if the neutral remains floating.

BTW, I've been looking at reviews of that Honda generator and although expensive, it looks like a really nice unit.

I'll give that a shot sometime, maybe this week.
The unit is really nice (but stupid expensive; a whole-home permanent generator costs the same without installation costs). It rolls around VERY easily despite being 280 pounds. It's pretty darn quiet and eco mode is nice. The power output is pretty nice (though I can hear some slight buzzing on my Verizon FiOS DVR box). It's got hoses that run to the bottom for draining fluids and whatnot -- some nice attention to detail.
It's going in for service despite being brand new -- it sometimes hunts/surges under ~1.5kW of load. Carb's probably dirty for some reason. Despite some of the crazy hunting/surging, the voltage remained constant. Pretty impressive.
Silly it only has two 5-20R's on it though.

 

[wycolo]

> That's just the L14-30 inlet. That's wired directly to the main panel inside the house using a 30 amp breaker and an interlock kit (so I can't backfeed the grid). [cinergi]

Could you identify and source this interlock kit? Was it supplied by your power company?

Using the Honda in a mobile setting such as pulling behind a Tesla on a small trailer, requires some sort of ground connection, simulated or otherwise. Directly connected out in the wild both the UMC and the Clipper Creek CS-60 fail to charge the MS. With the CS-60 the neutral is disconnected, as required, but I have the green (ground) to use somehow. Awaiting informed suggestions.
--

 

[cinergi]

> That's just the L14-30 inlet. That's wired directly to the main panel inside the house using a 30 amp breaker and an interlock kit (so I can't backfeed the grid). [cinergi]

Could you identify and source this interlock kit? Was it supplied by your power company?

Using the Honda in a mobile setting such as pulling behind a Tesla on a small trailer, requires some sort of ground connection, simulated or otherwise. Directly connected out in the wild both the UMC and the Clipper Creek CS-60 fail to charge the MS. With the CS-60 the neutral is disconnected, as required, but I have the green (ground) to use somehow. Awaiting informed suggestions.
--

It's a universal interlock kit -- just physically prevents the main and generator inputs from being on at the same time (even with the panel removed). It's pretty similar to something like http://www.gordonelectricsupply.com/tsimages/SQAREDE05421_51_PE_002.jpg but it's not specific to my panel (which is a Murray). My electrician supplied it so I don't know the exact source/model/etc ... but they're readily available in many electrical supply stores (including Home Depot). Using this, only the hot leads are disconnected (which is important, given the generator I'm hooking up has a floating neutral).

In a purely mobile scenario, there are various considerations for generators (depending on size and on whether neutral is bonded with ground, etc). It's pretty complex to understand and I always have to look it up. For example, read this post: Neutral bonding and generator - DoItYourself.com Community Forums

Though that doesn't really answer your question. I'm not sure how you'd (safely, at least) do it without grounding the generator.

 

[redi]

> That's just the L14-30 inlet. That's wired directly to the main panel inside the house using a 30 amp breaker and an interlock kit (so I can't backfeed the grid). [cinergi]

Could you identify and source this interlock kit? Was it supplied by your power company?

http://www.interlockkit.com

 

[EchoDelta]

If the rollers for the wheels won't work due to diameter, how about a treadmill?

..and some pillows. A lot of pillows, actually.

 

[brianman]

@EchoDelta - Excellent image.

I'd love to see some napkin calculations about what charge rate this might offer. Make whatever reasonable assumptions you deem useful.

 

[Kalud]

@EchoDelta Awesome!