360V DC input split phase 120V/240V AC inverter

[summit]

is there any reason other all-in-one inverter can not support the high DC-PV input from an EV's high DC ? it seems the main requirement is the inverter's ability to limit the incoming current via the battery charging max current setting.

Am using an 5000-w auto-transformer to get 120vac from the 240vac all-in-one. This particular transformer can accept a few different inputs (220,240,...) and was getting a hum when the connection was not balanced (center tap for Neutral was not exactly in the middle). Now with the correct center-tap, no more hum. It's important to use a fuse/circuit breaker between the inverter 240vac output and the transformer though.

 

[alexbeatlw]

is there any reason other all-in-one inverter can not support the high DC-PV input from an EV's high DC ? it seems the main requirement is the inverter's ability to limit the incoming current via the battery charging max current setting.

Am using an 5000-w auto-transformer to get 120vac from the 240vac all-in-one. This particular transformer can accept a few different inputs (220,240,...) and was getting a hum when the connection was not balanced (center tap for Neutral was not exactly in the middle). Now with the correct center-tap, no more hum. It's important to use a fuse/circuit breaker between the inverter 240vac output and the transformer though.

I'm not a fan of autotransformers since they do not provide any isolation. And actually, in my case - converting 230vac to 120vac to be used inside of the camper - they aren't allowed per NFPA 70 551.20(E).

Not sure what're the autotransformers NFPA restrictions (if any) for the residential wiring.

 

[summit]

good to know, isolating transformer is for sure ideal, but can be quite pricey. My usage is only for during outage, hopefully rare and short duration. In fact, the off-grid system is completely disconnected (except for ground) during normal grid-on via transfer switch.

 

[Hedges]

I'm not a fan of autotransformers since they do not provide any isolation. And actually, in my case - converting 230vac to 120vac to be used inside of the camper - they aren't allowed per NFPA 70 551.20(E).

That is under heading 551.20 Combination Electrical Systems.

I think that means don't take in 120VAC, step down to 12VAC with an auto-transformer, and used for 12V load (might be AC, might be rectified for DC.) This would not have galvanic isolation, and if connected reverse polarity it could expose user to 120VAC "ground" connection of cigarette lighter outlets and vehicle chassis.

I wouldn't see any problems with using autotransformer to provide 240VAC or 120/240V split phase from 120VAC.

If I wanted to get autotransformer function without violating letter of the law, I would buy an isolation transformer and use its two primary windings as autotransformer.

 

[yabert]

As I said, try feeding 120V into 240V primary windings, or 240V into 480V worth of primary windings. No-load current will be a fraction as much, and VA should be much closer to W.

Thanks for your help Hedges. But really, I will have to scratch my head around this because I'm not sure to understand/know what to try.

 

[Hedges]

You were just doing something like this feeding 220VAC to ends of transformer and grounding center tap to make a neutral?



Do exactly that with primary windings of a 240/480 to 120/240 transformer.
In this case, H2 connected to H3 and ground, call it neutral.
H1 and H4 are L1 and L2.

Don't use secondary (unless you have some reason to.)
The primary acts as an auto transformer, but the windings are designed for 240/480V (would saturate partially at that voltage.)
Because you're using them for 120/240V, half the rated voltage, it is far from saturation and draws far less current.
It is good for the same current it is rated for, but less wattage at reduced voltage.

 

[summit]

yep, just have to mind the winding's gage and thus max current. Given an isolating transformer, with primary & secondaryy windings, what's the advantage to configure as an auto-transfomer ? wouldn't using both windings offer additional benefit of isolation ? can't beat the price (size, efficiency) of auto-transformer though

 

[summit]

inspired by the VanaBolt, plz comment/shoot-hole in 1st draft of poor-man-V2H. BTWay, is there chassis ground bounding between the Vanabolt & Util-Grd ?

 

[yabert]

inspired by the VanaBolt, plz comment/shoot-hole in 1st draft of poor-man-V2H.

You should start your new interesting thread about EV V2H in the section danger zone or show and tell.
It will be way more pertinent than this thread started 3 years ago when I'm looking for an inverter.

BTWay, is there chassis ground bounding between the Vanabolt & Util-Grd ?

No.

 

[yabert]

inspired by the VanaBolt

Oh! And the Vanabolt have been repair and have a new paint ?
Vanabolt... well, I would mean my 64 kWh battery back up on wheels.

 

[summit]

You should start your new interesting thread about EV V2H in the section danger zone or show and tell.
It will be way more pertinent than this thread started 3 years ago when I'm looking for an inverter.

did a quick search but no return 'danger zone" section ? got a link ? thanks. Any worry about the Bolt's pack about the "fire" issue ? nice paint job btw

 

[Hedges]

Danger Zone! (Advanced User Experiments Only)

diysolarforum.com

 

[yabert]

Any worry about the Bolt's pack about the "fire" issue ?

No, my Bolt had his battery recall after 100 000 km / one year ago ?
Thanks GM for the new battery ?

 

[Gimpster]

Hey everyone, sorry to barge into a thread... but I am a Bolt owner and have been toying with using it as battery backup system. I have a 12VDC -> 120VAC inverter setup on it with an Anderson connector, but lately I've had some utility reliability issues making me want to do more. Specifically I'd love to be able to do split phase to power large portions of my smallish (by American standard at 900 sq ft) house, and I'd been doing testing on using the HVDC cabin heater branch before I bumped into this thread. The market for all-in-one HVDC -> split phase inverters is not the greatest right now it seems.

I want to be clear I am not affiliated with anyone, but I've been looking at this unit:

EG4 6000XP Off-Grid Inverter | 8000W PV Input | 6000W Output | 480V VOC Input | 48V 120/240V Split Phase | All-In-One Solar Inverter

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

I looked at its manual in detail, and it appears to have an option to disable the MPPT function totally, which if I'm reading that right, is kinda interesting:



Maybe I'm over thinking it, but I've been warned by multiple people now I should think twice before connecting my EV's battery to an MPPT solar input on an inverter, yet I see tons and tons of people doing it with success on projects like this, primarily using Nissan Leaf battery assembles.

Home

This software enables EV battery packs to be used for stationary storage in combination with solar inverters. - dalathegreat/BYD-Battery-Emulator-For-Gen24

github.com

 

[summit]

Maybe I'm over thinking it, but I've been warned by multiple people now I should think twice before connecting my EV's battery to an MPPT solar input on an inverter, yet I see tons and tons of people doing it with success on projects like this, primarily using Nissan Leaf battery assembles.

plz share links or elaborate on these warnings. I am about to bench test this set up. Thx

 

[Gimpster]

plz share links or elaborate on these warnings. I am about to bench test this set up. Thx

There were concerns earlier in this very thread, and I've received some warnings from various folks in the DIY community. Again, I do not know how serious to take them given the amount of people I see doing second-life projects now for home storage with EV batteries + off grid inverters.

As for elaboration, I believe their concern(s) revolve around potential ramp rate issues.

 

[yabert]

Wow! The EG4 6000XP is the inverter I'm waiting for as you can see the title of this thread. Thanks.
Please let us know if this work well with your EV and don't hesitate to ask if you need more Bolt details.

 

[summit]

Wow! The EG4 6000XP is the inverter I'm waiting for as you can see the title of this thread. Thanks.
Please let us know if this work well with your EV and don't hesitate to ask if you need more Bolt details.

just picked up a relatively inexpensive PowMr 5.5K 48v, $299+$45 shipping, discontinued model I guess. The first thing I insisted was to remove the N-G screw, it took a few back/forth Whatsapp messaging to convince PowMr that it is necessary. Now I can use an autotransformer to get proper split phase for US grid. It's probably the same screw in your PowMr 24v, I can post a pix if you want.

I'm bench testing it right now, and am quite happy that the AC-OUT is able to AC-couple an Enphase M215 (in an uncontrolled manner, ie no throttling). In fact, a surprising discovery is the AC-OUT side can flow & charge back to the 48v battery. PowMr is surprised too. But it kinda makes sense because in line-mode, the AC-IN and AC-OUT are direct connection.

 

[yabert]

Now I can use an autotransformer to get proper split phase for US grid. It's probably the same screw in your PowMr 24v, I can post a pix if you want.

Really interesting. Sure I'm interested.

 

[Gimpster]

Wow! The EG4 6000XP is the inverter I'm waiting for as you can see the title of this thread. Thanks.
Please let us know if this work well with your EV and don't hesitate to ask if you need more Bolt details.

If I do buy it, I'll let you know and update this thread. Its one of those things I "don't really need, but would like". I have an Enphase based PV array on my home, and would love some home backup/storage options given how often I've been losing power lately, but its kinda offends me that between my Bolt and Tesla Model 3 LR I have what.... 140kWh gross of battery sitting in my garage on wheels. So while doing a "Bolt Battery Backup" feels like the right move, .... I think you get my meaning :D

But yah the That EG4 unit (actually made by Luxpower) seems to be everything I want, and everyone says no need for an auxiliary battery with it.

One clarification I will ask, your "Vanabolt" hehe ... the car is not shutting itself down due to perceived parasitic draw on the AC HV output? I saw an post in this thread on that, but it wasn't clear the outcome to me.

I can say for sure the car doesn't care if the heater is unplugged idle. My car literally sat there for hours in my test and never did it log a code lol. I have GDS2 so I scanned it with that.